Paraduodenal hernia with intestinal necrosis: Three case reports and review of literature

Abstract

BACKGROUND

Paraduodenal hernia (PDH) is the most common congenital internal hernia and a rare cause of acute abdominal pain. Its clinical manifestations and signs often mimic common abdominal emergencies, leading to significant challenges in clinical diagnosis and imaging differentiation. This article reports three cases of right PDH (RPDH) and reviews 173 PDH-related articles published in the past 20 years, hoping to assist clinical diagnosis and treatment, minimize misdiagnosis and missed diagnosis, and improve patient outcomes.

CASE SUMMARY

We report three cases of RPDH, including one rare subtype (case 1). The patients were a 42-year-old woman, a 54-year-old man, and an 18-year-old man, all of whom presented to the emergency department with acute abdominal pain as the initial symptom, with varying durations and accompanying symptoms including nausea, vomiting, and diarrhea. Contrastenhanced computed tomography imaging suggested RPDH. Two patients (case 1 and case 3) underwent emergency exploratory laparotomy, while the remaining patient (case 2) initially received conservative treatment but required surgery 11 days later. All the three patients were diagnosed with RPDH intraoperatively and recovered well postoperatively. No recurrent abdominal pain was reported during long-term outpatient follow-up.

CONCLUSION

PDH presents non-specifically as acute abdominal pain; diagnosis relies on contrast computed tomography, and timely surgery is needed for complications.

Key Words: Paraduodenal hernia; Intestinal necrosis; Contrast-enhanced computed tomography; Gastrointestinal emergency; Internal hernia; Case report

Core Tip: This report describes three patients with paraduodenal hernia (PDH), including a rare case of right-sided PDH. Contrast-enhanced computed tomography is the preferred imaging modality for diagnosis. Surgical intervention is the definitive treatment for PDH, and exploratory laparotomy is indicated in critical situations. A PubMed search identified 173 articles reporting 197 cases of PDH published over the past 20 years. These cases highlight that PDH should be considered in the differential diagnosis of unexplained acute abdominal pain, and timely imaging evaluation and surgical intervention are key to improving patient outcomes.

INTRODUCTION

Internal hernia is a condition in which abdominal viscera herniate through a congenital or acquired defect in the peritoneum or mesentery. Its overall incidence is less than 1%[1]. Paraduodenal hernia (PDH) is the most common congenital internal hernia, accounting for approximately half of all cases[1,2-5]. It is classified into left-sided PDH (LPDH, also called Landzert’s hernia) and right-sided PDH (RPDH, also called Waldeyer’s hernia) types. The left-sided type is more common, and its incidence is higher in males, with a male-to-female ratio of approximately 3:1[3,6-9]. The pathogenesis of PDH is associated with abnormal midgut rotation during embryogenesis, and the underlying mechanisms of LPDH and RPDH are different[1-7,10-18]. Generally, it is accepted that LPDH is caused by abnormal midgut rotation during embryogenesis, and the jejunal loop fails to complete its normal anatomical migration. Under normal circumstances, the jejunal loop rotates from left to right and is eventually fixed on the right side of the abdominal cavity. Instead, it becomes embedded within a peritoneal fossa lateral to the left duodenum (known as Landzert’s fossa). RPDH, by contrast, results from either inadequate rotation of the superior mesenteric artery and its anterior cecal branches or abnormal fusion of the right mesocolon with the posterior abdominal wall. This leads to the formation of an abnormal peritoneal recess adjacent to the duodenum (Waldeyer’s fossa), into which bowel or other abdominal contents may herniate[6,13,19,20].

Clinically, PDH often presents with recurrent postprandial abdominal pain, so it is easily misdiagnosed as chronic gastritis, duodenal ulcer, or other gastrointestinal disorders; it may also manifest as acute intestinal obstruction. Due to the non-specific clinical presentation of PDH and its considerable variability among patients, the diagnosis is challenging[5-7,11]. The reported misdiagnosis rate ranges from 30% to 50%[21], with an average duration of misdiagnosis of 1 month to 3 months. In untreated acute PDH, the mortality even reaches 20%-50% due to intestinal necrosis and septic shock[8,10]. Hence, internal hernia should be considered in the differential diagnosis of intestinal obstruction; timely diagnosis and clinical intervention are critical for reducing mortality.

This article reports three cases of RPDH managed in our hospital after retrospectively retrieving data from hospital records. The patients, a 42-year-old woman, an 18-year-old man, and a 54-year-old man, all presented to the emergency department (ED) with acute abdominal pain. In all three cases, computed tomography (CT) imaging suggested PDH, which was subsequently confirmed during exploratory laparotomy.

CASE PRESENTATION

Chief complaints

Case 1: A 42-year-old woman presented to the ED with an 8-hour history of abdominal pain.

Case 2: An 18-year-old man presented to the ED with a 1-week history of abdominal pain, which had worsened over the past day.

Case 3: A 54-year-old man presented to the ED with a 5-day history of abdominal pain, which recurred for 5 hours.

History of present illness

Case 1: The patient developed upper abdominal pain after lunch 8 hours prior to presentation, characterized by continuous, severe colicky pain. This was accompanied by nausea, vomiting (gastric contents), and diarrhea (yellow watery stools).

Case 2: The patient developed upper abdominal pain without obvious cause 1 week prior to presentation, which was moderate, paroxysmal dull pain, accompanied by nausea, vomiting (gastric contents), and diarrhea (yellow watery stools).

Case 3: The patient developed persistent diffuse abdominal pain after eating 5 days prior to presentation, which was difficult to describe. There was no radiating pain, nausea, or vomiting, and the pain resolved spontaneously. Therefore, the patient did not seek medical attention. Five hours prior to admission, the patient experienced recurrent abdominal pain with the same characteristics as the initial episode, without obvious cause.

History of past illness

Medical history was unremarkable in all cases.

Personal and family history

Personal and family histories were unremarkable in all cases.

Physical examination

Case 1: Vital signs: Temperature (T) 37.8 °C, heart rate (HR) 98 bpm, respiratory rate (RR) 20 breaths/minute, blood pressure (BP) 107/70 mmHg. The abdomen was flat, with tenderness and rebound tenderness in the right upper quadrant. No visible peristalsis was observed. No abdominal mass was palpable, and shifting dullness was not elicited.

Case 2: Vital signs: T 36.6 °C, HR 59 bpm, RR 20 breaths/minute, BP 114/68 mmHg. The abdomen was flat, with tenderness and rebound tenderness in the right upper quadrant. No visible peristalsis was observed. No abdominal mass was palpable, and shifting dullness was not elicited.

Case 3: Vital signs: T 36.7 °C, HR 68 bpm, RR 18 breaths/minute, BP 164/89 mmHg. The abdomen was soft and protuberant with an asymmetric contour. Tenderness was noted in the right upper quadrant without rebound tenderness, and a soft, non-pulsatile mass measuring approximately 15 cm × 10 cm was palpable.

Laboratory examinations

Case 1: White blood cell count (WBC): 10.61 × 10⁹/L (elevated); neutrophils (Neut%): 93% (elevated); lymphocytes (Lymph%): 4.5% (decreased); monocytes%: 1.6% (decreased); eosinophils%: 0.1% (decreased). Other laboratory findings were within normal limits.

Case 2: WBC: 7.79 × 10⁹/L (normal); Neut%: 65.9% (normal); Lymph%: 25.8% (normal); prothrombin time: 15.1 seconds (elevated); international normalized ratio: 1.21 (elevated); direct bilirubin: 4.4 μmol/L (elevated), indirect bilirubin: 18.5 μmol/L (elevated), homocysteine: 28.7 μmol/L (elevated). Other laboratory findings were within normal limits.

Case 3: WBC: 8.0 × 10⁹/L (normal); Neut%: 82.1% (elevated); Lymph%: 11.3% (decreased); monocytes%: 5.9% (normal); eosinophils%: 0.3% (decreased). Other laboratory findings were within normal limits.

Imaging examinations

Case 1: Contrast-enhanced CT (CECT) (Figure 1) revealed RPDH. Scanning parameters: Slice thickness, 1 mm; contrast agent, iohexol 300 mgI/mL; dose, 1.5 mL/kg.

Figure 1 Multiplanar computed tomography images and intraoperative observations of internal hernia of case 1. A-C: Multiplanar computed tomography images [coronal (A), sagittal (B), axial (C)] showing the location of the herniated lesion (orange star), consistent with the imaging features of internal hernia. The scale bar in (C) represents 50 mm; D and E: Intraoperative views: Gross appearance of the herniated bowel loops (indicated by the blue arrow) under laparoscopy; the dashed box denotes the target area, and the orange star marks the location of the herniated bowel (D). Intraoperative image after surgical manipulation (indicated by the blue arrow), showing the necrotic small intestine, with the orange star indicating the region of the necrotic bowel segment (E).

Case 2: CECT (Figure 2) revealed intestinal malrotation, complicated by internal hernia (suspected PDH or cecal hernia) and ischemic and edematous changes in the intestinal wall, along with a small amount of pelvic effusion. Scanning parameters: Slice thickness, 1 mm; contrast agent, iohexol 300 mgI/mL; dose, 1.5 mL/kg.

Figure 2 Multiplanar computed tomography images of case 2. A: Coronal view; B: Sagittal view; C: Axial view. The area marked by the orange star indicates the herniated bowel loops, whose location and morphology are consistent with the imaging characteristics of internal hernia (bowel loops herniated into an abnormal space). The scale bar in (C) represents 50 mm.

Case 3: CECT (Figure 3) showed a saccular opacity in the right upper quadrant, complicated by partial small bowel obstruction suspected to be secondary to an internal hernia, most likely PDH. Scanning parameters: Slice thickness, 1 mm; contrast agent, iohexol 300 mgI/mL; dose, 1.5 mL/kg.

Figure 3 Multiplanar computed tomography images of case 3. A: Coronal view; B: Sagittal view; C: Axial view. The area marked by the orange star indicates the herniated bowel loops, whose location and morphology are consistent with the imaging characteristics of internal hernia (bowel loops herniated into an abnormal space). The scale bar in (C) represents 50 mm.

FINAL DIAGNOSIS

Case 1

RPDH with intestinal necrosis.

Case 2

RPDH; congenital intestinal malrotation; intestinal obstruction; small bowel perforation; localized peritonitis.

Case 3

RPDH with partial small-bowel obstruction.

TREATMENT

Case 1

Emergency exploratory laparotomy was performed. During the operation, approximately 200 mL of bloody ascites was observed in the abdominal cavity. A segment of small intestine approximately 100 cm in length was twisted along its mesentery at a point approximately 320 cm from the ligament of Treitz, and then coursed upward along the descending duodenum posterior to the portal vein. It passed through a 2 cm diameter peritoneal defect and herniated into the lesser sac. The bowel was edematous and dusky. The small intestine was completely retracted and observed in warm saline-soaked gauze for 20 minutes. Although some segments regained normal color and viability, a 20 cm segment remained non-viable (Figure 1D-E). The peritoneal defect posterior to the portal vein was closed with a continuous suture using 3-0 polyester non-absorbable surgical suture. To ensure adequate blood supply to the anastomosis, the resection margins were extended to include viable tissue, and a 40 cm segment of small intestine located approximately 320 cm from the ligament of Treitz was resected, followed by end-to-end anastomosis. A closed suction drain was placed beneath the right hepatic lobe.

Case 2

After symptomatic treatment including fasting, intravenous fluids, gastrointestinal decompression, antispasmodic therapy, and anti-infective therapy, the abdominal pain improved, and the patient was discharged 5 days later. Six days after discharge, the patient was readmitted with abdominal pain and underwent emergency laparotomy. During the operation, 100 mL of bloody ascites and chronic appendicitis were observed. Intraoperative findings confirmed RPDH, with the small intestine herniating through the congenital defect posterior to the portal vein and inferior to the suspensory ligament of the duodenum. A 1-cm thick fibrous band between the appendix and the sigmoid colon was also identified. A 300-cm segment of small intestine was twisted around this band and herniated into the ileocecal region and the retrocolic space posterior to the ascending colon, causing localized obstruction. A segment of small intestine 100 cm proximal to the ileocecal region had a small bowel perforation and seromuscular tear, and the proximal small intestine was dilated. After aspiration of the ascites, the intestinal adhesions were lysed, the appendix and the adhesive band were removed, the ruptured small intestine was repaired with interrupted sutures, and the defect which was posterior to the portal vein and inferior to the suspensory ligament of the duodenum was closed with a continuous suture using 3-0 polyester non-absorbable surgical suture.

Case 3

Emergency exploratory laparotomy was performed. During the operation, a mesenteric defect was identified adjacent to a mesenteric artery. The entire small intestine had passed through this defect and was herniated into the retroperitoneal recess posterior to the right mesocolon; the bowel appeared viable. The hernia orifice was incised and the incarcerated intestinal loop was reduced from the retroperitoneal recess. The retroperitoneum was closed with a continuous suture using 3-0 polyester non-absorbable surgical suture, and the jejunum was fixed distal to the ligament of Treitz.

OUTCOME AND FOLLOW-UP

Case 1

The patient recovered well and was discharged on postoperative day 7. At 1-month follow-up, she remained asymptomatic with no recurrence of abdominal pain.

Case 2

The patient recovered well and was discharged on postoperative day 15 of the second hospitalization. At 6-month follow-up, he remained asymptomatic with no recurrence of abdominal pain.

Case 3

The patient was discharged on postoperative day 6. He was readmitted 9 days later with abdominal pain and vomiting. CT showed partial small-bowel obstruction and a small amount of free pelvic fluid. He received symptomatic treatments including gastrointestinal decompression, nil per os, intravenous fluids, antispasmodic and anti-infective therapy, and was discharged 5 days later. At 10-year follow-up, the patient remained asymptomatic with no recurrence of abdominal pain.

DISCUSSION

We retrieved 173 case reports on PDH published over the past 20 years from the PubMed database, comprising a total of 197 cases (Table 1). Selected statistical results are presented in graphical format (Figure 4). Internal hernia is defined as a pathological condition in which abdominal viscera, most commonly a segment of small bowel, owing to its high mobility and relatively free anatomical location, protrude into another compartment of the abdominal cavity through a normal or abnormal defect or crypt on the peritoneum or mesentery[1-4,6,10-13]. This abnormal displacement not only compromises organ function but may also result in blood flow disorders due to strangulation, leading to life-threatening complications such as intestinal necrosis and septic shock. Based on anatomical location, internal hernias can be classified into PDH, foramen of Winslow hernia, pericecal hernia, sigmoid mesocolon-related hernia, mesenteric hernia, omental hernia, supravesical hernia, and pelvic hernia[5,8]. Different types of internal hernias vary in clinical presentation, diagnostic difficulty, and treatment strategies due to differences in the anatomical structure of the hernia site. Based on etiology, internal hernias are divided into congenital and acquired forms. Congenital hernias are predominantly associated with anomalies of embryonic development[1-7,10-18]; some patients may remain asymptomatic for years until triggers such as increased intra-abdominal pressure provoke symptom onset in adulthood. Acquired hernias most frequently result from prior abdominal surgery (the leading cause, accounting for approximately 70%), trauma or inflammation[1,5,8]. The overall incidence of internal hernias is low (less than 1%)[1,3,5,11], among which PDH accounts for nearly half of all cases[1-5], making it the most common congenital internal hernia and the focus of this report. PDH is categorized into LPDH and RPDH. LPDH is approximately three times more common than RPDH[1,3,6,8,9], and the condition is approximately three times more common in males than in females[1,3,6-9]. The age at diagnosis typically ranges from 40 years to 60 years, with a mean of approximately 38.5 years[22]. These data indicate that young and middle-aged adults are the primary affected population, and clinicians should maintain a high index of suspicion for PDH in this age group with unexplained abdominal pain. The pathogenesis of PDH is closely related to midgut rotation during embryogenesis, while the underlying mechanisms differ between LPDH and RPDH. It is generally accepted that LPDH results from abnormal midgut rotation during embryogenesis. Under normal circumstances, the jejunal loop rotates from left to right and is eventually fixed on the right side of the abdominal cavity. When this rotation process is incomplete or aberrant, the jejunal loop fails to complete its normal anatomical migration and instead becomes embedded within a peritoneal fossa lateral to the left duodenum, the Landzert’s fossa. RPDH, in contrast, is caused by either inadequate rotation of the superior mesenteric artery and its anterior cecal branches, or by abnormal fusion of the right mesocolon with the posterior abdominal wall. This creates the formation of an abnormal peritoneal recess, the Waldeyer’s fossa, adjacent to the duodenum, into which the small bowel or other abdominal contents may herniate[6,13,19,20]. Some authors have further subclassified RPDH into three types based on anatomical and etiological features[23].

Figure 4 Epidemiological and clinical characteristics of paraduodenal hernia. A: Paraduodenal hernia (PDH) showed a marked male predominance: 138 male cases vs 58 female cases, with 1 case of unclear gender, consistent with literature reports of male bias; B: Left-sided PDH was most common (n = 146), compared with 50 cases of right-sided PDH and 1 case of indeterminate laterality, reflecting anatomical predisposition to left-sided herniation; C: Highest incidence occurred in middle-aged adults (35-54 years, n = 81), followed by older adults (≥ 55 years, n = 43) and adolescents (13-18 years, n = 19). Cases were rare in infants and young children, suggesting a link to age-related abdominal changes or chronic intra-abdominal pressure; D: Cross-sectional imaging (computed tomography/multi-detector computed tomography/contrast-enhanced computed tomography, n = 167) was the most frequent preoperative diagnostic tool, followed by intraoperative confirmation (n = 124). Less common methods included barium contrast studies, magnetic resonance imaging, laparoscopy, and paracentesis, highlighting computed tomography’s central role in PDH diagnosis. PDH: Paraduodenal hernia; NR: Not reported; CT: Computed tomography; MDCT: Multi-detector computed tomography; CECT: Contrast-enhanced computed tomography; MRI: Magnetic resonance imaging.

Table 1 Summary of reported paraduodenal hernia cases retrieved from PubMed (2005-2025).

Ref.	Sex	Age	Side	Symptoms	Duration of illness	Intestinal necrosis	Preoperative diagnosis confirmed	Diagnostic method	Misdiagnosis/delay	Surgical method	Outcome
Shrestha et al[1]	M	51 years	Left	Abdominal pain, bilious vomit, inability to pass stool or flatus	5 days	Y	Y	CT	NR	Exploratory laparoscopy	C/R
Wassef et al[10]	M	21 years	Left	Abdominal pain, vomit, nausea	Several months	N	N	Surgery	Y	Laparoscopic exploration	Obstruction, reoperation
Deshmukh et al[11]	M	33 years	Left	Abdominal pain, nausea, vomit	2 years	N	N	CT and surgery	NR	Laparoscopic exploration	C/R
Vel et al[6]	M	25 years	Left	Abdominal pain, vomit	2 months	N	N	CECT and surgery	Y	Laparoscopic exploration	C/R
Alshdaifat et al[12]	M	31 years	Left	Abdominal pain, vomit, constipation	3 days	N	N	CT with oral and intravenous contrast and surgery	NR	Exploratory laparoscopy	Reoperation
Broadhurst et al[13]	M	50 years	Left	Epigastric pain, vomit	12 hours	N	Y	CECT	NR	Exploratory laparoscopy	C/R
Deflaoui et al[2]	M	45 years	Left	Epigastric pain, bilious vomiting	Acute	N	Y	CT	NR	Exploratory laparoscopy	C/R
Sah et al[3]	M	59 years	Left	Abdominal pain, vomit, inability to pass stool or flatus	3 days	N	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Nguyen et al[4]	M	49 years	Right	Abdominal pain, bilious vomit, constipation	2 days	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Bhagvat et al[5]	M	30 years	Left	Abdominal distension, vomiting, obstipation	2 days	N	Y	CECT	NR	Laparoscopic exploration	C/R
Fysel et al[7]	M	Early 30 s	Right	Abdominal pain, bilious vomit	3 months	N	Y	CT	NR	Robotic surgery	C/R
Yodying[14]	F	56 years	Left	Abdominal pain, vomit	1 day	Y	Y	CT	NR	Laparoscopic exploration	C/R
Kadravello et al[15]	F	13 years	Left	Abdominal distension, vomit	1 week	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Shah et al[16]	M	15 years	Right	Abdominal pain, vomit	6 months	Y	N	Surgery	NR	Exploratory laparoscopy	Death
Tavasolizadeh and Dalili et al[17]	M	26 years	Right	Abdominal pain	1.5 months	N	N	Double-contrast CT and surgery	Y	Exploratory laparoscopy	C/R
Charara et al[18]	F	19 years	Left	Abdominal pain, nausea	2 years	N	Y	CT	NR	Laparoscopic exploration	C/R
Filotico et al[36]	NR	72 years	Left	Intraoperative incidental finding	NR	N	N	Surgery	NR	Laparoscopic exploration	C/R
Tanaka et al[8]	F	86 years	Right	Abdominal pain	8 hours	Y	N	Surgery	Y	Exploratory laparoscopy	C/R
Brogna et al[9]	M	83 years	Left	Abdominal pain, vomit	Acute	N	N	Contrast-enhanced MDCT	Y	Exploratory laparoscopy	C/R
Atak et al[37]	M	47 years	Right	Abdominal pain, vomit	Acute	Y	N	Surgery	NR	Exploratory laparoscopy	C/R
H et al[31]	M	24 years	Right	Vomiting, pain in the right hypochondrium and right lumbar region	2 weeks	N	Y	CECT	Y	Exploratory laparoscopy	C/R
Alblowi et al[38]	M	48 years	Right	Abdominal pain, nausea	24 hours	N	Y	Barium upper gastrointestinal study and CECT	NR	Laparoscopic exploration	C/R
Bhardwaj et al[39]	F	NR	Left	Intraoperative incidental finding	NR	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Cobb et al[19]	M	3 years	Left	Abdominal pain, constipation, anorexia, insomnia, vomit	6 days	N	N	CT and surgery	Y	Laparoscopic exploration	C/R
Ohira et al[40]	F	72 years	Right	Nausea, vomit, diarrhea, liver dysfunction, hypokalemia	7 years	N	Y	3D-CT and endoscopic duodenography	Y	Exploratory laparoscopy	C/R
Wang et al[23]	M	33 years	Right	Abdominal pain	4 hours	N	N	CT and surgery	Y	Exploratory laparoscopy	C/R
Hina et al[41]	M	36 years	Left	Abdominal pain, vomit, nausea, inability to pass stool or flatus	3-4 years	Y	N	Surgery	Y	Exploratory laparoscopy	C/R
Shukla et al[42]	M	Teenager	Left	Abdominal pain	Over 1 year	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Anwar et al[43]	M	32 years	Left	Abdominal pain, vomit	Since childhood	N	N	Surgery	NR	Exploratory laparoscopy	C/R
AlSafadi and Smyk[44]	F	5 years	Left	Stomach pain, vomit, fever	NR	NR	NR	Autopsy	NR	NR	Death
Xue et al[22]	F	Early 30’s	Left	Abdominal pain, nausea, vomit	20 years	N	N	CT and surgery	NR	Laparoscopic exploration	C/R
Trabelsi et al[45]	M	59 years	Left	Intestinal obstruction	Acute	N	Y	CT	NR	Exploratory laparoscopy	C/R
Puerta Vicente et al[46]	M	53 years	Right	Abdominal pain, distention	Acute	N	Y	CT	NR	Exploratory laparoscopy	C/R
Rampal et al[47]	M	26 years	NR	Abdominal pain, bilious vomit, constipation	3 days	Y	N	Surgery	NR	Exploratory laparoscopy	Ostomy
Lamprou et al[35]	F	37 years	Right	Abdominal pain, nausea	6 hours	N	Y	CT	NR	Exploratory laparoscopy	C/R
Tong et al[48]	M	50 years	Left	Abdominal pain, nausea, vomit	12 hours	N	Y	CT	NR	Laparoscopic exploration	C/R
Wang et al[49]	M	8 years	Left	Cryptorchidism	NR	N	N	Surgery	NR	Laparoscopic exploration	C/R
Giordano et al[50]	M	19 years	Left	Abdominal pain, nausea, vomit	6 months	N	N	Surgery	Y	Exploratory laparoscopy	Reoperation
Vierstraete and Maes[51]	M	42 years	Left	Abdominal pain, vomit	12 hours	N	N	Surgery	Y	Laparoscopic exploration	C/R
Gosalvez-Tejada et al[52]	F	15-week-old	Left	Bilious emesis	11 weeks	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Hudák et al[53]	M	39 years	Left	Abdominal pain, vomit	3 years	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Ikoma et al[32]	M	9 years	Left	Abdominal pain	3 years	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Somuncu and Bozdağ[34]	M	28 years	Left	Abdominal pain	Acute	N	N	CT and surgery	NR	Laparoscopic exploration	C/R
Chikara et al[27]	M	30 years	Left	Abdominal pain, bilious vomit, a mass in left hypochondrium	14 years	N	N	Surgery	Y	Laparoscopic exploration	C/R
Chikara et al[27]	M	21 years	Left	Abdominal pain	15 hours	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Poudel et al[54]	M	36 years	Right	Abdominal pain, vomit	1.5 months	N	Y	CT	NR	Exploratory laparoscopy	C/R
Moshref et al[55]	M	55 years	Left	Abdominal pain, nausea, diarrhea	5 years	N	Y	CT	Y	Laparoscopic exploration	C/R
Hasegawa et al[56]	F	17 years	Left	Abdominal pain	Since childhood	N	Y	CECT	Y	Laparoscopic exploration	C/R
Rajput et al[20]	F	20 years	Left	Abdominal pain, nausea, vomit	2 years	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Manojlović et al[57]	M	39 years	Left	Abdominal pain, vomit	Since childhood	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Zachariah et al[58]	M	41 years	Left	Abdominal pain, constipation, postprandial bloating	1 week	N	Y	CECT	NR	Exploratory laparoscopy	C/R
Oshita et al[59]	M	30 years	Right	Abdominal pain, nausea, vomit	10 years	N	Y	CECT and upper gastrointestinal contrast radiography	Y	Laparoscopic exploration	C/R
Omarov et al[60]	M	59 years	Right	Abdominal pain	4 days	N	Y	CT with oral and intravenous contrast	NR	Laparoscopic exploration	C/R
Ismavel et al[33]	M	23 years	Right	Abdominal pain, vomit	2 hours	Y	N	Surgery	NR	Exploratory laparoscopy	C/R
Vanmali et al[61]	M	57 years	Left	Abdominal pain, vomit	Recurrent	N	Y	CT with oral and intravenous contrast	NR	Exploratory laparoscopy	C/R
Udo and Obong[62]	M	33 years	Left	Abdominal pain, distention, vomit, inability to pass stool or flatus	6 hours	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Bollampally et al[63]	M	29 years	Right	Abdominal pain, distention, bilious vomit	NR	N	Y	CECT	Y	Exploratory laparoscopy	C/R
Misheva et al[64]	F	42 years	Left	Abdominal pain, nausea, vomit	Acute	N	Y	CT	NR	Laparoscopic exploration	C/R
Xu et al[65]	M	38 years	Left	Vomit, hematemesis	2 days	N	N	CT, ultrasound-guided abdominal puncture and Surgery	NR	Exploratory laparoscopy	C/R
Mizouni et al[66]	M	28 years	Left	Abdominal pain	1 day	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Peru et al[67]	M	29 years	Right	Abdominal pain	Acute	N	Y	CT	NR	Exploratory laparoscopy	C/R
Vu and Bui[68]	F	19 years	Left	Abdominal pain, distension, vomit	24 hours	N	N	CT and surgery	NR	Laparoscopic exploration	C/R
Kadhem et al[69]	M	26 years	Left	Abdominal pain, nausea, vomit	2 months	N	Y	CT	NR	Exploratory laparoscopy	C/R
John et al[70]	M	29 years	Left	Abdominal pain, nausea	24 hours	N	Y	CT	Y	Laparoscopic exploration	C/R
John et al[70]	F	39 years	Left	Abdominal pain, nausea, vomit	Several years	N	Y	CT with oral and intravenous contrast	Y	Laparoscopic exploration	C/R
John et al[70]	F	29 years	Right	Abdominal pain, nausea, vomit	1 day	N	N	Surgery	Y	Robotic surgery	Reoperation
Kwan et al[71]	F	18 years	Right	Abdominal pain, vomit, weight loss	6 weeks	N	Y	CT with oral and intravenous contrast	NR	Laparoscopic exploration	C/R
Ma et al[72]	M	23 years	Left	Abdominal pain, vomit, constipation	12 hours	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Sakamoto and Lefor[73]	M	79 years	Left	Abdominal pain	5 years	N	Y	CT	Y	Laparoscopic exploration	C/R
Walkner and Nebiker[74]	M	37 years	Right	Abdominal pain, nausea, vomit	Acute	N	N	CT and surgery	NR	Laparoscopic exploration	C/R
Cho et al[75]	M	34 years	Left	Abdominal pain, postprandial nausea, vomit	Acute	N	N	Surgery	NR	Laparoscopic exploration	C/R
Sinensky et al[76]	M	53 years	Left	Abdominal pain	Acute	N	Y	CT	NR	Exploratory laparoscopy	C/R
Al Otaibi et al[77]	F	24 years	Left	Abdominal pain	Since childhood	N	Y	CECT	Y	Exploratory laparoscopy	C/R
Cho et al[78]	M	30 years	Right	Abdominal pain, vomit	1 year	N	N	CECT and surgery	NR	NR	C/R
Kulendran et al[79]	M	25 years	Left	Abdominal pain, vomit, constipation	16 hours	N	N	Surgery	NR	Laparoscopic exploration	C/R
Lopez et al[80]	M	16 years	Left	Abdominal pain, nausea, vomit, constipation	5 years	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Jin et al[81]	M	83 years	Left	Abdominal pain	8 hours	N	Y	CECT	NR	Exploratory laparoscopy	C/R
Moussa et al[82]	M	46 years	Left	Abdominal pain, vomit	3 days	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Takagishi et al[83]	F	56 years	Right	Abdominal pain, nausea, vomit	6 hours	N	N	Surgery	Y	Laparoscopic exploration	C/R
Kim et al[84]	M	4 years	Right	Abdominal pain, bilious vomit	3 years	N	Y	CT	Y	Exploratory laparoscopy	C/R
Bodur et al[85]	M	22 years	Left	Abdominal pain, vomit	NR	N	Y	CT	NR	Laparoscopic exploration	C/R
Manipadam et al[86]	F	31 years	Right	Abdominal pain, distension, vomit	2 months	N	N	CT and surgery	Y	Laparoscopic exploration	C/R
Martins et al[87]	F	17 years	Left	Abdominal pain	2 days	N	Y	Ultrasonography and CT	NR	Exploratory laparoscopy	C/R
Gökçal et al[88]	M	39 years	Left	Epigastric cramps, nausea, vomit	NR	N	Y	CT	Y	Laparoscopic exploration	C/R
Sleiman et al[89]	M	76 years	Left	Abdominal pain, anorexia, nausea, vomit, constipation	24 hours	N	Y	CT	NR	Exploratory laparoscopy	C/R
Wakabayashi et al[90]	M	76 years	Left	Abdominal pain	NR	N	N	Surgery	NR	Laparoscopic exploration	C/R
Alila et al[91]	M	50 years	Left	Abdominal pain,vomit, inability to pass stool or flatus	48 hours	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Alila et al[91]	F	18 years	Right	Abdominal pain	Acute	Y	N	Surgery	Y	Exploratory laparoscopy	C/R
Joseph et al[92]	M	43 years	Right	Abdominal pain, nausea, vomit, constipation	10 years	N	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Kozman and Fisher[93]	F	15 years	Left	Abdominal pain, anorexia, nausea, vomit, fever	12 hours	N	N	Surgery	Y	Exploratory laparoscopy	Reoperation
Lin and Liu[94]	M	16 years	Left	Abdominal pain, vomit, bloody stool	acute	Y	Y	CT	NR	Exploratory laparoscopy	C/R
Volpi et al[95]	M	59 years	Left	Abdominal pain	1 year	N	N	Surgery	NR	Exploratory laparoscopy	Vomit, nausea and delayed gastric emptying after the surgery
Indiran and Maduraimuthu[96]	M	19 years	Left	Abdominal distention, constipation, vomit	3 days	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Barbosa et al[97]	M	73 years	Left	Abdominal pain, distention, vomit	acute	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Winder et al[24]	M	34 years	Left	Postprandial abdominal pain	3 years	N	N	Surgery	NR	Laparoscopic exploration	C/R
Liu[98]	M	35 years	Left	Abdominal pain	1 day	N	Y	CT with oral and intravenous contrast	NR	Exploratory laparoscopy	C/R
Kulkarni et al[99]	M	36 years	Left	Abdominal pain, distention, vomit	1 week	N	Y	CT	Y	Laparoscopic exploration	C/R
Kulkarni et al[99]	M	42 years	Left	Subacute intestinal obstruction	1 year	N	Y	CT	Y	Laparoscopic exploration	C/R
Mehra et al[100]	M	46 years	Right	Vomit, abdominal pain	3 days	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Mehra et al[100]	M	23 years	Right	Abdominal pain, distention, bilious vomit	Since childhood	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Zizzo et al[101]	M	43 years	Left	Abdominal pain, nausea, vomit	2 days	N	Y	CT	NR	Laparoscopic exploration	C/R
Yu et al[102]	F	40 years	Left	Abdominal pain	2 hours	N	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Lim et al[25]	F	42 years	Left	Postprandial abdominal pain, distention	2 years	N	N	CT and surgery	Y	Laparoscopic exploration	C/R
Gusz and Wright[103]	M	69 years	Left	Abdominal pain	2 years	N	N	Surgery	NR	Laparoscopic exploration	C/R
Suwanthanma et al[104]	M	80 years	Left	Abdominal pain, inability to pass stool or flatus	2 hours	Y	Y	CT	Y	Exploratory laparoscopy	Wound dehiscence and lung complication due to underlying COPD
Shi et al[105]	M	14 years	Left	Postprandial vomit, abdominal pain, nausea, syncope	6 years	Y	N	Surgery	Y	Exploratory laparoscopy	An additional 12 operations, sepsis, renal failure, duodenal stump leak, full parenteral nutrition
Tomino et al[106]	M	23 years	Right	Abdominal pain, nausea, vomit	Acute	N	Y	CT	NR	Laparoscopic exploration	C/R
Licciardello et al[107]	M	45 years	Left	Abdominal pain, vomit, constipation	10 days	Y	N	CT and surgery	Y	Exploratory laparoscopy	C/R
Assenza et al[108]	M	67 years	Left	Abdominal pain, distention, diarrhoea, vomit	1 day	N	Y	CT	NR	Laparoscopic exploration	C/R
Poh et al[109]	M	77 years	Left	Abdominal pain, vomit	10 hours	N	Y	CT	NR	Exploratory laparoscopy	Postoperative ileus, relieved after conservative treatment
Cundy et al[28]	M	55 years	Left	Abdominal pain, constipation, vomit, a soft non-pulsatile mass in the left lower quadrant of abdomen	3 years	Y	N	CT and surgery	Y	Exploratory laparoscopy	Melaena stool
Lee and Choi[110]	F	74 years	Left	Abdominal pain	3 hours	N	Y	CT	NR	Laparoscopic exploration	C/R
Hassani et al[111]	M	55 years	Left	Abdominal pain, vomit	Several hours	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Erdas et al[112]	F	32 years	Right	Abdominal pain, nausea, vomit	2 years	N	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Bouchentouf et al[113]	F	47 years	Left	Abdominal pain, vomit	Several years	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Cengiz et al[114]	M	43 years	Left	Abdominal pain, distention, nausea, vomit, constipation	1 day	N	Y	CT	NR	Exploratory laparoscopy	C/R
Siddika et al[29]	M	35 years	Left	Postprandial vomit, abdominal pain, a mass in the left upper quadrant of abdomen	Since childhood	N	Y	CT	Y	Laparoscopic exploration	C/R
Torcivia et al[115]	F	47 years	Left	Intraoperative incidental finding	NR	N	N	Surgery	NR	Laparoscopic exploration	C/R
Öztaş et al[116]	M	42 years	Left	Abdominal pain, nausea, vomit	Since childhood	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Martín-Lagos-Maldonado et al[117]	M	52 years	Right	Abdominal pain, nausea	Several months	N	N	CECT and surgery	NR	Laparoscopic exploration	C/R
Al-Khyatt et al[118]	M	47 years	Left	Abdominal pain, bilious vomit, a tender mass in the left upper quadrant of abdomen	2 years	N	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Mozaffar et al[119]	F	41 years	Left	Constipation, anorexia, bilious vomit	3 days	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Manfredelli et al[120]	F	86 years	Right	Abdominal pain, distention, vomit, nausea, constipation	1 day	Y	N	Surgery	NR	Exploratory laparoscopy	C/R
Coakley et al[121]	M	25 years	Left	Abdominal pain	2 years	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Omland and Hougen[122]	F	73 years	Left	Abdominal pain, distention, diarrhea, constipation	10 days	NR	NR	Autopsy	Y	NR	Death
Kondo and Adachi[123]	M	76 years	Right	Abdominal pain, vomit, nausea	3 years	N	N	Surgery	Y	Exploratory laparoscopy	NR
Hafeez Bhatti and Khan[124]	F	18 years	Left	Abdominal pain, vomit, constipation	5 days	Y	N	Surgery	Y	Exploratory laparoscopy	Ostomy
Hussein et al[125]	F	59 years	Left	Abdominal pain, bilious vomit, nausea	10 years	N	N	CT with oral and intravenous contrast and surgery	Y	Laparoscopic exploration	C/R
Akbulut et al[126]	M	42 years	Left	Abdominal pain, vomit, nausea, constipation	3 days	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Nam et al[127]	F	12 years	Left	Abdominal pain, postprandial nausea	1 month	N	Y	CT and small bowel series	NR	Laparoscopic exploration	C/R
Nam et al[127]	M	3 months	Left	Irritability	Several days	N	Y	CT and small bowel series	NR	Laparoscopic exploration	C/R
Lu and Liu[128]	F	45 years	Right	Abdominal pain	NR	N	Y	CT	NR	Exploratory laparoscopy	C/R
Lu and Liu[128]	M	15 years	Right	Abdominal pain, bilious vomit	2 years	N	Y	CT	NR	Exploratory laparoscopy	C/R
Lam et al[129]	M	14 years	Right	Abdominal pain, constipation, bilious vomit, nausea	Acute	Y	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Nuño-Guzmán et al[130]	M	41 years	Right	Postprandial vomit, nausea, abdominal pain, distention	3 months	N	Y	CT and upper gastrointestinal series	Y	Exploratory laparoscopy	C/R
de Paula et al[131]	F	27 years	Left	Abdominal pain, nausea	6 days	N	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Liao et al[132]	F	45 years	Right	Abdominal pain	12 hours	N	Y	CECT	NR	Exploratory laparoscopy	C/R
Al-Mufarrej et al[133]	M	42 years	Left	Abdominal pain	6 hours	N	N	Surgery	NR	Laparoscopic exploration	C/R
Ghorbel et al[134]	F	2 months	Left	Bilious vomit	12 hours	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Zaz et al[135]	M	60 years	Left	Abdominal pain, vomit, a mass in right upper quadrant of abdomen	8 hours	Y	N	Surgery	Y	Exploratory laparoscopy	C/R
Fernández-Rey et al[136]	M	39 years	Left	Abdominal pain	NR	N	Y	CT	NR	Exploratory laparoscopy	C/R
Falk et al[137]	F	76 years	Left	Abdominal pain, vomit, nausea, a mass in left upper quadrant of abdomen	1 day	Y	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Parmar and Parmar[138]	M	38 years	Left	Abdominal pain	5 years	N	N	CT and surgery	NR	Laparoscopic exploration	C/R
Abdullah et al[139]	F	48 years	Right	Abdominal pain, distention	24 hours	N	Y	CT	NR	Exploratory laparoscopy	C/R
Yun et al[140]	M	38 years	Left	Abdominal pain, vomit	Several hours	N	Y	Upper gastrointestinal series with small bowel follow-through	Y	Exploratory laparoscopy	C/R
Lederer et al[141]	F	A fetus at 30 weeks and 3 days of gestation	Right	Ascites developed at 16 weeks of gestation and gradually increased, caesarean section at 30 + 3 weeks gestation, no spontaneous respiration, cyanotic, petechial bleeding and curled dammed veins on the abdomen	14 weeks	N	N	Autopsy	Y	NR	Death
Khalaileh et al[142]	F	53 years	Left	Abdominal pain, vomit, nausea	Acute	N	Y	CT	NR	Laparoscopic exploration	C/R
Fukada et al[143]	M	46 years	Right	Abdominal pain	Acute	N	N	Surgery	NR	Exploratory laparoscopy	SMAS, duodenojejunostomy
Seya et al[144]	F	77 years	Left	Intraoperative incidental finding	NR	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Lin et al[145]	M	30 years	Left	Abdominal pain, bilious vomit	1 week	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Downes and Cawich[146]	M	47 years	Left	Abdominal pain	1 year	Y	N	Surgery	Y	Exploratory laparoscopy	C/R
Okan et al[147]	M	43 years	Left	Abdominal pain, distention, a mass in the left upper quadrant	NR	N	Y	CT	NR	Exploratory laparoscopy	C/R
Teng and Yamout[148]	M	16 years	Left	Abdominal pain, vomit	Several hours	N	N	CT upper gastrointestinal contrast and Surgery	NR	Exploratory laparoscopy	C/R
Cho et al[149]	M	63 years	Left	Abdominal pain, vomit	1 week	Y	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Bittner et al[150]	F	26 years	Right	Abdominal pain, vomit, nausea	6 years	N	N	CT of the abdomen with oral and intravenous contrast and surgery	Y	Laparoscopic exploration	C/R
Poultsides et al[151]	F	67 years	Left	Abdominal pain, bilious vomit, constipation	3 days	N	N	CT and surgery	NR	Laparoscopic exploration	C/R
Uchiyama et al[152]	F	80 years	Left	Abdominal pain	NR	N	N	CT, upper gastrointestinal series and surgery	NR	Laparoscopic exploration	C/R
Wang et al[153]	M	22 years	Left	Abdominal pain	2 years	N	Y	CT	NR	Exploratory laparoscopy	C/R
Kuzinkovas et al[154]	M	59 years	Left	Rectal bleeding, lethargy, tiredness, abdominal pain	1 year	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Jarboui et al[155]	M	17 years	Right	Abdominal pain, vomit	NR	Y	N	CT and surgery	NR	Exploratory laparoscopy	Intestinal obstruction, reoperation
Lin et al[156]	M	15 years	Right	Abdominal pain, vomit, nausea	NR	N	Y	MDCT	Y	Exploratory laparoscopy	C/R
El Sharkawy and Al-Nakshabandi[157]	M	38 years	Left	Abdominal pain, distention, nausea, vomit	2 weeks	N	Y	Small bowel follow-through examination, CECT	NR	Laparoscopic exploration	C/R
Prada-Arias et al[158]	F	9 months	Right	Abdominal pain, bilious vomit	4 months	N	Y	CECT	Y	Exploratory laparoscopy	C/R
Descloux and Wiens[159]	F	65 years	Left	Intraoperative incidental finding	NR	Y	N	Surgery	NR	Exploratory laparoscopy	C/R
Shoji et al[160]	M	60 years	Left	Abdominal pain	NR	N	Y	CT, MRI and barium enema	NR	Laparoscopic exploration	C/R
Dassinger and Eubanks[161]	M	13 years	Right	CT incidental finding	NR	N	N	CT and surgery	NR	Laparoscopic exploration	C/R
Kandpal et al[162]	M	26 years	Left	Abdominal pain, vomit	3 days	N	Y	MRI, CECT and barium enema	Y	NR	C/R
Papaziogas et al[163]	F	35 years	Left	Abdominal pain, vomit, dyspepsia	Since childhood	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Brehm et al[164]	F	54 years	Left	Abdominal pain	Several years	N	Y	CT	Y	Exploratory laparoscopy	C/R
Thoma et al[165]	F	72 years	Left	Abdominal pain	30 years	N	N	Gastrointestinal barium study, CT and surgery	Y	Exploratory laparoscopy	C/R
Singh et al[166]	M	37 years	Left	Abdominal pain	1 week	N	N	Surgery	NR	Exploratory laparoscopy	C/R
Socas Macías et al[167]	M	47 years	Left	Abdominal pain, vomit	Since adolescence	N	N	Surgery	Y	Exploratory laparoscopy	C/R
Kurachi et al[168]	F	47 years	Left	Abdominal pain, nausea	NR	N	Y	CT	NR	Exploratory laparoscopy	C/R
Meeussen et al[26]	M	58 years	Left	Postprandial abdominal pain, nausea, vomit, constipation	Several weeks	N	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Cingi et al[169]	M	30 years	Left	Abdominal pain, nausea, vomit	6 months	N	N	CT and surgery	Y	Exploratory laparoscopy	C/R
Moon et al[170]	M	18 years	Left	Abdominal pain, nausea, vomit	Acute	N	N	CT and surgery	NR	Exploratory laparoscopy	C/R
Huang YM et al[171]	M	24 years	Left	Abdominal pain, bilious vomit	6 months	N	N	CT, upper gastrointestinal series and surgery	NR	Laparoscopic exploration	C/R
Yang et al[172]	F (3), M (13)	15-67 years	Left (13), right (3)	Postprandial abdominal pain (3); nausea, vomiting, and severe epigastric pain after strenuous exercise or sudden postural changes (13); hematochezia (6); a mass in left/right upper quadrant of abdomen (3)	2-4 hours (6), 5-7 hours (10)	Y (4), N (12)	Y (2), N (14)	X-ray (16), CT (6), BUS (6), abdominal paracentesis (3) and surgery (14)	Y (14), NR (2)	Exploratory laparoscopy (16)	C/R (16)
Ovali et al[173]	F	52 years	Left	Abdominal pain, nausea, vomit	3 years	N	Y	CT of the abdomen with oral and intravenous contrast	NR	Non-surgical management	C/R
Tainaka et al[174]	F	3 years	Left	Abdominal pain, vomit	5 days	N	N	CT, small bowel follow-through image and surgery	NR	Exploratory laparoscopy	C/R
Osadchy et al[175]	M	48 years	Left	Abdominal pain, vomit	Several months	N	Y	CT of the abdomen with oral and intravenous contrast	Y	NR	C/R

Data derived from a systematic PubMed search (2005-2025) using the terms “paraduodenal hernia”. Inclusion criteria: Confirmed paraduodenal hernia, original patient data; exclusion: Duplicates. Two independent reviewers performed screening and data extraction. Sex: M: Male; F: Female; NR: Not reported. Side: Left: Left paraduodenal hernia; Right: Right paraduodenal hernia; NR: Not reported. Intestinal necrosis: Y: Yes; N: No; NR: Not reported. Preoperative diagnosis confirmed: Y: Preoperative diagnosis confirmed by imaging/pathology; N: Not confirmed preoperatively; NR: Not reported. Misdiagnosis/delay: Y: History of misdiagnosis or delayed diagnosis; NR: Not reported. Outcome: C/R: Complete recovery; Reoperation: Required additional surgery; Death: Died during follow-up; Ostomy: Required ostomy; NR: Not reported. CT: Computed tomography; CECT: Contrast-enhanced computed tomography; MDCT: Multi-detector computed tomography; MRI: Magnetic resonance imaging; BUS: B-mode ultrasound; COPD: Chronic obstructive pulmonary disease; SMAS: Superficial musculoaponeurotic system.

Notably, in case 1, intraoperative findings showed that the small bowel had not herniated through the Waldeyer’s fossa or Winslow’s foramen, but instead passed from right to left through a congenital defect posterior to the portal vein and inferior to the suspensory ligament of the duodenum. This unusual hernia defect is rarely described in the literature, suggesting that RPDH may encompass a broader spectrum of anatomic variants than recognized. RPDH can present with highly variable clinical features. The presence of yellow watery stools in cases 1 and 2 may be attributable to increased intestinal peristalsis during acute or severe diarrhea, which precipitated the development of an internal hernia. Notably, the final diagnosis of case 2 included appendicitis, localized peritonitis, yet the patient had only localized tenderness in the right upper abdomen. This finding can be explained by the fact that the small intestinal perforation site was encapsulated by the lesser omental bursa and part of the greater omentum, which confined the inflammatory process locally and prevented generalized peritonitis. Chronic appendicitis was an intraoperative finding which did not account for the patient’s acute abdominal pain. Unconjugated hyperbilirubinemia observed in this patient was likely secondary to dehydration and systemic infection related to the acute abdominal condition. RPDH can present with highly variable clinical manifestations: Some patients remain asymptomatic for prolonged periods and are only incidentally diagnosed during physical examinations or workups for other conditions. Symptomatic patients typically present with recurrent postprandial abdominal pain[24-26], often described as dull or bloating, accompanied by nausea, vomiting, and other gastrointestinal symptoms. These chronic symptoms are easily misdiagnosed as common digestive disorders such as chronic gastritis or gastric ulcer. Some patients with symptoms may present acutely with severe, rapidly progressive abdominal pain and signs of intestinal obstruction (e.g., cessation of flatus and defecation), suggesting incarceration of the herniated bowel. Rarely, a palpable abdominal mass[27-29] (corresponding to the hernia sac and its contents) can be touched. Without effective treatment, the mortality rate among patients with acute presentations ranges from 20% to 50%[8,10]. The main causes of death include ischemic necrosis secondary to strangulation, septic shock, and multiple organ failure. Thus, timely diagnosis and treatment are essential to reduce mortality of PDH.

The main differential diagnoses of PDH include acute appendicitis (more common in young adults, with tenderness and rebound tenderness at McBurney’s point), mesenteric vascular embolism (acute severe abdominal pain, often with a history of atrial fibrillation), adhesive intestinal obstruction (history of prior abdominal surgery), and mesenteric lymphadenitis (more common in adolescents). The non-specific clinical manifestations of internal hernias often lead to delayed or wrong diagnosis. Clinical data indicate that approximately 30%-50% of patients with internal hernias are initially misdiagnosed with other digestive diseases, with an average delay of 1-3 months before confirmation[21]. A study in 2013 reported that 53% (47/89) of patients with internal hernia had a history of recurrent abdominal pain without a definitive diagnosis, which closely align with the aforementioned range[30]. Therefore, a clear diagnostic approach should be established in clinical diagnosis and treatment. When patients experience unexplained abdominal pain (such as recurrent postprandial abdominal pain or acute severe abdominal pain), the possibility of internal hernia should be considered, and rapid imaging evaluation should be performed. Traditionally, PDH is diagnosed using small-bowel following-through[27], but it has gradually been replaced due to its long examination time (2-4 hours) and multiple contraindications, including acute intestinal obstruction. Currently, multi-detector CT (MDCT) is increasingly used in internal hernia diagnosis and has become the first-line imaging modality[1,3,8,11] due to its high resolution, rapid imaging speed, and three-dimensional reconstruction capabilities, with reported diagnostic accuracy up to 95% and sensitivity of 95%-100%[1]. The characteristic CT findings of PDH consist of three key features: (1) Clustered distribution of dilated bowel loops at the hernia orifice, forming a “bowel mass”; (2) Mesenteric vascular abnormalities (e.g., congestion, engorgement, or displacement) caused by traction of the herniated bowel; and (3) The “whirl sign”, resulting from rotation of the mesenteric vessels and bowel[14,31-33]. In addition, MDCT can clearly demonstrate the vascular status of the herniated bowel, presence of intestinal ischemia or necrosis, and anatomical relationships with adjacent vessels and organs, thereby providing precise imaging guidance for assessing intestinal necrosis and for determining the need of intestinal resection. Surgery is the only curative treatment for PDH, with the goals of reducing bowel, managing the hernia sac, and repairing the defect. Intraoperatively, incarcerated bowel loops must be carefully assessed for viability. If ischemia or necrosis is identified, bowel resection and anastomosis should be performed. Hernia sac resection is not necessary. Small, non-adherent sacs may be left in situ to avoid vascular injury due to extensive dissection (in all three cases presented herein, the sac was not resected, and no recurrence of internal hernias was observed during follow-up). Depending on the size of the hernia orifice and the condition of the surrounding tissue, the defect may be closed primarily or repaired with mesh. During repair, the defect should be closed with adequate tension to prevent recurrence while avoiding undue tension that might compromise vascularity[27,34]. Postoperative small bowel obstruction in case 2 may have resulted from inadequate tension during primary suture closure of the hernia orifice. In addition, attention should be paid to avoiding damage to adjacent blood vessels, such as the inferior mesenteric vein.

Regarding the surgical approach, laparoscopic surgery is preferred in experienced medical centers owing to its advantages, including less postoperative pain, earlier resumption of oral intake (mean, 1.33 days), and shorter hospital stay (mean, 3.6 days)[34]. This approach is particularly suitable for hemodynamically stable patients without major complications such as perforation or bowel necrosis. Conversely, immediate laparotomy should be performed in patients with intestinal ischemia or strangulation, bowel perforation, marked intestinal dilation (diameter ≥ 4 cm)[35], high suspicion of bowel necrosis, contraindications to pneumoperitoneum, or when institutional experience or equipment is limited. Laparotomy provides adequate exposure, allowing rapid control of the problem and maximizing the chance of patient survival. In the present series, all three patients underwent laparotomy: Case 1 for intestinal necrosis, case 2 for complete incarceration, and case 3 for small bowel perforation with dense adhesions, indications that met the criteria for open surgery.

The diagnostic and treatment strategies for PDH include: (1) For patients with acute abdominal pain and suspected PDH, CECT should be performed; (2) If CECT demonstrates characteristic findings of PDH (e.g., clustered bowel loops, “whirl sign”, mesenteric vessel engorgement or displacement), emergency surgical evaluation is required; (3) For hemodynamically stable patients without serious complications (e.g., perforation, bowel necrosis), laparoscopic exploration is the preferred approach; (4) For patients with intestinal necrosis, perforation, or hemodynamic instability, immediate laparotomy is indicated; and (5) Intraoperatively, bowel viability must be carefully assessed, non-viable segments should be resected, and hernia sac resection and hernia orifice repair should be tailored to intraoperative findings. This report has the following innovations: (1) It reports three cases of RPDH, including a rare subtype of RPDH (case 1), in which the small intestine herniated into the lesser sac through a congenital defect posterior to the portal vein, suggesting a broader spectrum of anatomic variants of RPDH; (2) It provides clinical data on an adolescent patient with PDH (case 2), highlighting the importance of considering this diagnosis in young patients presenting with unexplained abdominal pain; and (3) It further supports the efficacy of exploratory laparotomy in the management of complex PDH cases (e.g., intestinal necrosis, perforation, or dense adhesions), offering evidence to guide surgical decision-making in emergency settings.

This study has several limitations. It was a single-center, retrospective study with a small sample size (three cases), which may have introduced selection bias; long-term follow-up data (e.g., 5-year recurrence rate, bowel function) are lacking; and the outcomes of laparoscopic surgery vs open surgery for PDH were not quantitatively compared. Future research should focus on multi-center prospective randomized controlled trials comparing the long-term efficacy of laparoscopic and open surgery; development of artificial intelligence-assisted MDCT diagnostic systems for PDH; and further investigation into the genetic and molecular mechanisms underlying congenital PDH.

CONCLUSION

The clinical presentation of PDH is usually non-specific, rendering diagnosis challenging and requiring both extensive clinical knowledge and experience. CT, especially CECT, is widely regarded as the preferred imaging modality for definitive diagnosis. Surgery remains the definitive treatment for PDH. Although laparoscopic surgery offers distinct advantages over open surgery, exploratory laparotomy remains a critical option in emergency settings such as bowel necrosis or perforation. This report presents three cases of RPDH, including a rare subtype of RPDH, and provides valuable insights for clinical diagnosis and treatment. All three patients underwent open surgery; the procedures were uneventful, incisions healed well, and no hernia recurrence was observed during outpatient follow-up. Therefore, we emphasize that timely diagnosis and surgical intervention are crucial for improving patient outcomes.