Posterior approach to Calot’s triangle in situs inversus totalis: A case report and review of literature

Abstract

BACKGROUND

Situs inversus totalis (SIT) is a rare congenital anomaly in which the thoracic and abdominal viscera are completely mirrored, complicating spatial orientation and surgical techniques during laparoscopic cholecystectomy (LC). With the conventional anterior approach, this mirrored anatomy often causes instrument crossing, restricted manipulation, and surgeon disorientation. The posterior approach may offer a more ergonomic pathway aligned with the mirror-image anatomy, but its clinical utility and technical rationale in SIT remain incompletely defined.

CASE SUMMARY

A 33-year-old man with SIT presented with a 6-month history of intermittent upper left quadrant abdominal pain, which had worsened over the preceding month. He was diagnosed with chronic cholecystitis with focal necrosis (gangrenous change). A three-port LC was performed in a mirror-image modified American position using a posterior approach to Calot’s triangle. The procedure was completed uneventfully within 64 minutes, with no biliary injury or perioperative complications. A closed-suction drain was placed intraoperatively and removed on postoperative day 3. The patient was discharged on postoperative day 4 and remained asymptomatic at the 3-month follow-up, with no evidence of bile leakage or surgical-site infection.

CONCLUSION

For SIT patients undergoing LC, accessing Calot’s triangle via the posterior approach is a feasible surgical strategy.

Key Words: Situs inversus totalis; Laparoscopic cholecystectomy; Mirror-image anatomy; Posterior approach to Calot’s triangle; Case report

Core Tip: Mirror-image anatomy in situs inversus totalis can increase ergonomic and cognitive demands during laparoscopic cholecystectomy, particularly when Calot’s triangle dissection is challenging. We describe a posterior approach to Calot’s triangle as a stepwise access strategy in which a posterior window is developed and dissection proceeds in a posterior-to-anterior direction to facilitate sequential anatomic confirmation. This pathway may help limit instrument crossing and reduce the need for repeated reorientation in situs inversus totalis cases while maintaining adherence to the critical view of safety principles.

INTRODUCTION

Situs inversus totalis (SIT) is a rare congenital anomaly characterized by complete mirror-image transposition of the thoracic and abdominal organs, with an estimated incidence of 1 in 10000-20000 and a slight male predominance[1]. This autosomal recessive condition is associated with genetic abnormalities on chromosome 7, chromosome 8, and chromosome 14[2,3]. Although most individuals with SIT are asymptomatic, the reversed anatomy complicates both diagnosis and treatment. For example, biliary diseases may present with atypical symptom localization, such as upper left quadrant pain in cholecystitis, which increases the risk of misdiagnosis or delayed intervention[4]. More critically, failure to recognize the mirror-image anatomy or to adjust conventional surgical landmarks can lead to serious iatrogenic injury[5].

Laparoscopic cholecystectomy (LC) in patients with SIT is technically demanding because the mirror-image anatomy conflicts with the surgeon’s spatial orientation and the standard ergonomic setup[6]. Even with a preoperative diagnosis, surgeons often encounter instrument crossing, counterintuitive hand movements, and reduced operative efficiency. Since the first successful LC in a patient with SIT was reported in 1991[7], several technical modifications have been proposed, including adjustments to surgeon positioning, trocar placement, single-incision surgery, and robotic assistance. In complex cases featuring severe inflammation or dense adhesions in Calot’s triangle, however, the traditional anterior approach can exacerbate these ergonomic difficulties. While a posterior approach to Calot’s triangle may theoretically align better with the mirror-image anatomy, its application and technical rationale in SIT have not been thoroughly elaborated in the literature.

This report describes LC in a patient with SIT and, together with a review of the literature, provides a descriptive summary of technical challenges that may arise when managing Calot’s triangle in mirror-image anatomy. On this basis, we discuss factors relevant to the posterior approach from anatomical, cognitive, and operational perspectives. This report is intended to supplement case-level experiential evidence and may inform individualized surgical planning and perioperative decision-making for patients with SIT undergoing LC.

CASE PRESENTATION

Chief complaints

Intermittent upper left abdominal pain persisted for 6 months but worsened over the past month.

History of present illness

Six months prior, the patient began experiencing intermittent upper left abdominal pain without obvious precipitating factors. The pain worsened after the patient consumed greasy food and was accompanied by a bitter taste and belching. No fever, nausea, vomiting, or jaundice occurred. During the past month, pain increased in frequency, disrupting daily activities and sleep.

History of past illness

The patient had a confirmed history of SIT. There was no significant history of cardiac, pulmonary, or renal disease; no prior abdominal surgery; no hypertension or diabetes mellitus; and no drug allergies.

Personal and family history

The patient did not smoke or consume alcohol. There was no family history of situs inversus or gallbladder disease.

Physical examination

The vital signs were as follows: Temperature, 36.8 °C; heart rate, 78 beats/minute; blood pressure, 120/76 mmHg; and respiratory rate, 18 breaths/minute. Cardiac auscultation revealed prominent heart sounds in the right hemithorax. The abdomen was flat, with mild tenderness in the epigastrium and upper left quadrant, without rebound tenderness or guarding. Murphy’s sign was negative. The liver and spleen were not palpable below the costal margins, and bowel sounds were normal. The body mass index was 20.4 kg/m². The patient was classified as American Society of Anesthesiologists physical status II.

Laboratory examinations

Blood tests showed leukocytosis with neutrophil predominance, with a white blood cell count of 12.50 × 10⁹/L [reference range: (3.50-9.50) × 10⁹/L] and neutrophils accounting for 84.4% (reference range: 40.0%-75.0%). Mild lymphopenia was present, with an absolute lymphocyte count of 0.72 × 10⁹/L [reference range: (1.10-3.20) × 10⁹/L]. Electrolyte testing showed mild hypokalemia (serum potassium, 3.41 mmol/L; reference range: 3.50-5.30 mmol/L). Liver function tests showed mildly elevated bilirubin levels [total bilirubin, 31.2 μmol/L (reference range: 5.0-28.0 μmol/L), and direct bilirubin, 9.6 μmol/L (reference range: 0-7.0 μmol/L)]. Cytokine testing revealed a markedly elevated interleukin-6 level (379.70 pg/mL; reference range: 0-5.30 pg/mL) and a mildly elevated interleukin-10 level (5.94 pg/mL; reference range: 0-4.91 pg/mL). Other liver and renal function indices were within normal limits, and no abnormalities were identified on additional evaluations, including urinalysis, coagulation testing, and tumor marker screening.

Imaging examinations

Abdominal ultrasonography revealed situs inversus, an irregular gallbladder wall, and fine echogenic sediment within the lumen. Two hyperechoic lesions with posterior acoustic shadowing were identified, with the larger lesion measuring approximately 1.3 cm. The intrahepatic and extrahepatic bile ducts were not dilated. Chest computed tomography (CT) confirmed dextrocardia (Figure 1A). Abdominal magnetic resonance imaging and magnetic resonance cholangiopancreatography (MRCP) revealed the liver and gallbladder in the upper left abdomen, with the pancreas, spleen, and kidneys on the right. The biliary and pancreatic ducts showed no abnormal dilatation or filling defects. The gallbladder was enlarged with wall thickening. Nodular filling defects were noted within the gallbladder lumen, extending to the cystic duct region; the larger defects measured approximately 1.1 cm in diameter. A small amount of pericholecystic fluid was present around the gallbladder fossa (Figure 1B).

Figure 1 Preoperative imaging confirming situs inversus totalis. A: Chest computed tomography showing dextrocardia; B: Magnetic resonance cholangiopancreatography demonstrating cholelithiasis and situs inversus totalis.

FINAL DIAGNOSIS

Chronic cholecystitis with focal necrosis (gangrenous change); SIT.

TREATMENT

The procedure was performed by an attending hepatobiliary surgeon (associate chief physician) with more than 5 years of surgical experience. A second senior surgeon was immediately available for intraoperative assistance. The operating room layout was adapted accordingly. After induction of general anesthesia, the patient was placed supine. Given situs inversus, a mirror-image modified American position was adopted: The surgeon and camera assistant stood on the patient’s right side, the scrub nurse on the left, and the laparoscopic stack was positioned toward the patient’s left shoulder. The operating table was placed in a 30° head-up position with a 20° right tilt. The primary surgeon was right-handed.

A three-trocar configuration was used, beginning with the placement of a 10-mm supraumbilical port and insufflation to 12 mmHg. A 5-mm auxiliary port was then established in the subxiphoid region, followed by a 10-mm primary working port positioned 2 cm below the left costal margin along the midclavicular line (Figure 2A). Diagnostic laparoscopy confirmed the anatomy in SIT.

Figure 2 Illustrates the operative setup and key steps in the posterior dissection of Calot’s triangle. A: Schematic diagram of laparoscopic port placement; B: Gallbladder located left of the falciform ligament with dense adhesions to the greater omentum; C: Posterior dissection of the cystic duct in Calot’s triangle; D: Posterior dissection of the cystic artery in Calot’s triangle.

The gallbladder was markedly distended and densely adherent to the greater omentum (Figure 2B). After the gallbladder contents were aspirated, the adhesions were carefully dissected to expose Calot’s triangle. Given the mirrored anatomy, a posterior approach to Calot’s triangle was used to avoid instrument crossing and to facilitate dissection in an avascular plane. The surgeon’s left hand, operating through the subxiphoid port, provided superior and medial traction on Calot’s triangle and retracted the liver. The right hand manipulated an electrocautery hook via the left subcostal port to dissect within the posterior triangle (posterior Calot’s triangle) and create a posterior window inferior to the cystic duct near the gallbladder infundibulum. Loose tissue posterior to the cystic duct was gently dissected to fully mobilize its posterior wall (Figure 2C). A dissector was passed through this posterior window and brought out anteriorly. The gallbladder was then retracted laterally with the left hand, while the right hand dissected the anterior aspect of Calot’s triangle. Alternating anterior and posterior dissection with the dissector and electrocautery hook continued until the triangle was fully delineated. Dissection was maintained above Rouviere’s sulcus and close to the gallbladder to protect the common bile duct.

The loose connective tissue within Calot’s triangle was bluntly dissected along the gallbladder neck. After the lower third of the gallbladder was separated from the liver bed, the fatty and lymphatic tissue in the triangle was cleared to skeletonize the cystic artery and cystic duct (Figures 2D and 3). After joint confirmation of these structures, the cystic artery was ligated with an absorbable ligating clip (Lapro-Clip™; Covidien, MA, United States) and divided. The gallbladder was then dissected from the liver bed using electrocautery. After clear identification of the cystic duct-common bile duct junction, the cystic duct was secured with two absorbable ligating clips (Lapro-Clip™; Covidien, MA, United States) and transected. The gallbladder specimen was retrieved through the enlarged subxiphoid port site. The operative field was irrigated, and hemostasis was confirmed. Given severe inflammatory edema with diffuse oozing, a closed-suction drain was placed in the gallbladder fossa for postoperative monitoring and to reduce the risk of fluid collection. The procedure concluded uneventfully without biliary injury. Perioperative management included intravenous levofloxacin in 0.9% sodium chloride (0.5 g once daily for six consecutive doses, administered from hospital day 1 through postoperative day 3). Venous thromboembolism prophylaxis consisted of early postoperative ambulation.

Figure 3 Schematic diagram of the posterior approach to Calot’s triangle. A posterior window is developed to enable a posterior-to-anterior dissection sequence and stepwise anatomic confirmation of the cystic duct and cystic artery. CA: Cystic artery; CD: Cystic duct; CHD: Common hepatic duct; CBD: Common bile duct.

OUTCOME AND FOLLOW-UP

The procedure was completed in 64 minutes. The postoperative course was uneventful, with no bleeding, bile leakage, or surgical-site infection. Drain output progressively decreased and remained nonbilious; the drain was removed on postoperative day 3 when the 24 hours output was < 15 mL. The patient was discharged on postoperative day 4. At the 3 months follow-up, there was no readmission or evidence of bile leakage or surgical-site infection.

DISCUSSION

SIT introduces significant clinical complexity because of the complete mirror-image arrangement of the thoracic and abdominal viscera[8]. Symptom localization can be deceptive; for example, cholecystitis or cholelithiasis typically presents with left hypochondriac pain, increasing the risk of misdiagnosis or treatment delay. Studies report that approximately 30% of SIT patients with acute cholecystitis experience epigastric pain, whereas 10% experience upper right quadrant pain, indicating that the central nervous system’s perception of visceral transposition does not fully align with the anatomical reality[9]. If SIT is unrecognized preoperatively, imaging studies may misinterpret the mirror-image anatomy as organ malposition or a pathological mass. Moreover, SIT is commonly associated with conditions such as Kartagener syndrome or congenital heart disease[10]. Cardiac transposition may produce electrocardiographic abnormalities and should be further evaluated with echocardiography[11]. Collectively, these factors increase anesthetic and perioperative risk, underscoring the need for systematic cardiopulmonary assessment and airway preparation before surgery[12,13]. Previous reports indicate that failure to recognize SIT preoperatively or inadequate preoperative preparation is a major contributor to serious intraoperative complications, including bile duct injury[5,14]. In contrast, other evidence indicates that systematic high-resolution preoperative imaging can reduce the operative time and improve surgical safety[15]. Consequently, a comprehensive preoperative imaging assessment - encompassing echocardiography, abdominal ultrasonography, CT, and MRCP - is fundamental for performing laparoscopic surgery safely in patients with SIT.

LC is the standard surgical treatment for symptomatic gallstones and cholecystitis. In patients with SIT, however, the mirror-image arrangement of the thoracic and abdominal viscera poses substantial technical challenges for LC[16]. This anatomic variation increases the demands on the surgeon’s spatial orientation, bimanual coordination, and laparoscopic proficiency and disrupts established operative workflows in conventional anatomy[17]. In the mirrored operative field, visual input no longer aligns with ingrained instrument-handling patterns and procedural logic, creating a persistent mismatch among instrument trajectory, visual feedback, and inherent motor programs[18]. Key steps in standard LC, particularly the exposure and dissection of Calot’s triangle, rely heavily on experience and muscle memory; under mirror-image conditions, these steps require continual cognitive recalibration and movement adjustment. This sustained cognitive load may impair procedural fluency, reduce surgical efficiency, and increase the risk of intraoperative error, particularly when exposure is limited or when inflammation is severe.

To address these challenges, several technical adaptations have been described in clinical practice. These include adjustments to surgeon positioning (e.g., a mirror-image modified American or French position), optimization of trocar placement, left-hand-dominant manipulation, and the use of single-incision laparoscopic or robot-assisted techniques. In this study, we report the successful surgical management of a patient with SIT and a difficult Calot’s triangle using a posterior approach to Calot’s triangle. In addition, we conducted a literature review by searching the PubMed/MEDLINE, Web of Science Core Collection, and Google Scholar databases for English-language reports describing LC in patients with SIT. Year filters were set to 2000-2026, and all searches were last performed on December 13, 2025. The full search strategies were as follows: PubMed/MEDLINE: [(“situs inversus” (Medical Subject Headings Terms) OR “situs inversus totalis” (title/abstract) OR “Kartagener syndrome” (title/abstract) OR “left-sided gallbladder” (title/abstract)] AND “cholecystectomy” (Medical Subject Headings Terms) AND English (language) AND humans (filter) AND [2000-2026 (publication date)]; Web of Science (topic): (“situs inversus totalis” OR “Kartagener syndrome” OR “left-sided gallbladder” OR “mirror image”) AND (“cholecystectomy” OR “gallbladder removal”), filtered to English and year published 2000-2026; Google Scholar: “situs inversus totalis” AND “cholecystectomy” (first 200 results screened; accessed on December 13, 2025). Reference lists of eligible articles were also manually screened to identify additional relevant cases. The inclusion criteria were as follows: (1) Case reports, case series, or review articles reporting original case(s) with extractable individual-level data for patients with imaging-confirmed SIT who underwent LC (multiport or single-incision); and (2) Availability of extractable patient-level data. The exclusion criteria were as follows: Reports of non-total situs inversus (e.g., partial situs inversus), cases involving concomitant major or therapeutic surgical procedures, insufficient operative detail to extract predefined perioperative variables, non-English publications, and unavailable full texts. Two authors independently screened the titles and abstracts and full texts and independently extracted predefined case-level variables using a standardized data-extraction form; discrepancies were resolved by discussion and consensus. Missing data were not imputed; analyses were performed on an as-reported basis, and denominators therefore varied across variables. The study identification, screening, eligibility assessment, and inclusion criteria are summarized in Figure 4.

Figure 4  Flow diagram of literature search and study selection.

Using this approach, we identified 110 reported SIT-LC cases, including the present case (Supplementary Table 1). Across the included reports, the mean age was 47.2 ± 12.8 years (range, 20-76 years; age available in 109 cases), and cases were more frequently reported in females [82 (74.5%)] than in males [28 (25.5%); Table 1]. Preoperative diagnoses were most commonly cholelithiasis/symptomatic gallstone disease (39.1%), followed by chronic cholecystitis (34.6%) and acute cholecystitis (24.4%); other diagnoses were infrequent (1.8%; Table 1). The most commonly described primary pain location was the upper left quadrant/hypochondrium (65.1%), followed by epigastric pain (25.7%), whereas right upper quadrant pain was uncommon (2.8%); cases described only as “abdominal pain” without a specified location were categorized as other/not specified (6.4%; Table 1). The reporting of preoperative imaging was heterogeneous. Ultrasonography was most frequently reported (89.1%), followed by chest radiography (69.1%) and abdominal CT (39.1%). Magnetic resonance imaging and MRCP were reported in 5.5% and 12.7% of the patients, respectively; preoperative endoscopic retrograde cholangiopancreatography was reported in 3.6% (Table 2). Operative management was described with variability across reports, including differences in port number/configuration and surgeon position. With respect to surgeon handedness, most procedures were performed by right-handed surgeons [79 (71.8%)], whereas left-handed surgeons were reported in only three cases (2.7%). One case (0.9%) described an ambidextrous approach or involvement of two surgeons, and in 27 cases (24.5%), surgeon handedness was not reported (Table 3). With respect to the position of the primary surgeon, the most common setup positioned the surgeon on the patient’s right side [86 (78.2%)], followed by the surgeon positioned between the patient’s legs [12 (10.9%)] and the surgeon on the patient’s left side [5 (4.5%)]. In seven cases (6.4%), the surgeon’s position was either not reported or described as other configurations (Table 3). Four-port LC predominated (73.6%), with smaller proportions managed using three-port (10.9%), five-port (4.5%), or single-incision approaches (10.9%; Table 3). As reported, the perioperative course was often described as uneventful: The median operative time was 65 minutes (interquartile range 50-80; range 30-135; n = 66), and the median postoperative stay was 2 days (interquartile range 1-3; range 1-8; n = 99; Table 4). Postoperative adverse events were uncommon (1.8%) and included early postoperative respiratory complications managed conservatively and a postoperative day-20 presentation due to retained choledocholithiasis requiring endoscopic retrograde cholangiopancreatography (Table 4).

Table 1 Demographic characteristics and clinical presentation of reported situs inversus totalis patients undergoing laparoscopic cholecystectomy (n = 110), mean ± SD/n (%).

Variables	Value
Demographics
Age, years (n = 109)	47.2 ± 12.8
Age, years (range)	20-76
Sex
Male	28 (25.5)
Female	82 (74.5)
Preoperative diagnosis
Chronic cholecystitis	38 (34.6)
Acute cholecystitis	27 (24.4)
Cholelithiasis/symptomatic gallstone disease	43 (39.1)
Other	2 (1.8)
Primary pain location
Left upper quadrant/hypochondrium	71 (65.1)
Epigastric	28 (25.7)
Right upper quadrant	3 (2.8)
Other/not specified	7 (6.4)

Age was missing in 1 case; the age summary is based on available cases (n = 109). Diagnostic categories were extracted as stated in the original reports and were not reclassified. Primary pain location was extracted as reported. Cases described only as “abdominal pain” without a specified location were categorized as “other/not specified”.

Table 2 As-reported preoperative investigations in reported situs inversus totalis-laparoscopic cholecystectomy cases (n = 110), n (%).

Variables	Value
Ultrasonography	98 (89.1)
Abdominal computed tomography	43 (39.1)
Magnetic resonance imaging	6 (5.5)
Magnetic resonance cholangiopancreatography	14 (12.7)
Chest radiography	76 (69.1)
Preoperative endoscopic retrograde cholangiopancreatography	4 (3.6)

Modalities were counted only when explicitly reported; non-mention was coded as “not reported” (not “not performed”). Percentages therefore reflect reporting frequency rather than true utilization. Multiple modalities could be reported per case; category totals may exceed 110. Magnetic resonance imaging and magnetic resonance cholangiopancreatography were coded separately according to explicit wording in the original reports.

Table 3 Operative set-up and technical adaptations in reported situs inversus totalis-laparoscopic cholecystectomy cases (n = 110), n (%).

Variables	Value
Surgeon handedness
Right-handed	79 (71.8)
Left-handed	3 (2.7)
Ambidextrous/two-surgeon	1 (0.9)
Other/not reported	27 (24.5)
Primary surgeon position
Surgeon on patient’s right side	86 (78.2)
Surgeon on patient’s left side	5 (4.5)
Surgeon between the legs	12 (10.9)
Other/not reported	7 (6.4)
Port strategy
3-port	12 (10.9)
4-port	81 (73.6)
5-port	5 (4.5)
Single-incision laparoscopic surgery	12 (10.9)

Variables were extracted only when explicitly stated; non-mention was coded as “not reported”. Data summarize reporting frequency across case reports/series and are descriptive only.

Table 4 Perioperative outcomes in reported situs inversus totalis-laparoscopic cholecystectomy cases (n = 110), median (interquartile range)/n (%).

Variables	Value
Operative time, minutes (n = 66)	65 (50-80)
Operative time, minutes (range)	30-135
Postoperative stay, days (n = 99)	2 (1-3)
Postoperative stay range, days	1-8
Postoperative adverse events
Adverse event reported	2 (1.8)
No adverse event reported	99 (90.0)
Adverse event not reported	9 (8.2)

In the mirror-image anatomy of SIT, operative difficulty is influenced not only by disease severity and technical approach but also by the surgeon’s habitual motor patterns and ergonomic adaptation. Mirror-image anatomy may amplify the effect of surgeon handedness on procedural fluency. Left-handed or ambidextrous surgeons may have an advantage because their instrument trajectories can align more naturally with the mirrored operative field, enabling anatomically intuitive dissection without major alterations to the operative sequence and potentially facilitating more stable exposure of Calot’s triangle[19]. In contrast, right-handed surgeons often must readapt instrument paths and spatial orientation to the mirror-image view, which can increase the difficulty of bimanual coordination and may increase the risk of bile duct injury because of instrument crossing and a less well-organized system[6]. To mitigate these challenges, a two-surgeon collaborative approach has been proposed in which each surgeon uses their dominant hand to dissect different aspects of Calot’s triangle to reduce instrument crossing and improve ergonomics[20]. Accordingly, during LC in patients with SIT, bimanual coordination - and its compatibility with mirror-image anatomy - likely influences both surgical safety and efficiency.

To address the operational challenges posed by mirror-image anatomy for right-handed surgeons, two main strategies are commonly described in the published case literature: Optimizing the operative angles by adjusting the surgeon’s position and trocar placement and utilizing single-port laparoscopic and robot-assisted surgical platforms. In multiport LC for patients with SIT, the American position is most frequently reported, followed by the French position[21,22]. Previous studies suggest that the American position, with mirrored trocar placement, may better align with right-handed operating habits and is therefore widely used[23]. However, it may be associated with limitations, including a restricted visual field and instrument crossing. In contrast, the French position has been described as providing a more direct coaxial view, which may improve exposure and reduce instrument interference[24]. Operationally, the American position seeks to accommodate right-handed surgeons through a mirrored port layout, whereas the French position aims to provide a more forward-facing view by reconfiguring spatial relationships. Overall, no uniformly adopted “standard” position for LC in SIT has been established in the available literature. In our view, patient positioning and port configuration should be individualized according to surgeon experience, team coordination, and intraoperative findings. Accordingly, a pragmatic approach is to use the setup with which the team is most familiar and to modify the operative plan as needed.

Beyond conventional multiport laparoscopy, single-incision laparoscopic surgery (SILS) and robot-assisted surgery offer advanced minimally invasive approaches for the mirror-image anatomy of SIT. SILS uses a single umbilical incision, which may improve cosmesis and reduce postoperative pain while providing an operative axis that partially accommodates mirrored anatomy, thereby facilitating Calot’s triangle dissection for right-handed surgeons[25,26]. Exposure can be maintained using internal anchoring or percutaneous suspension techniques rather than assisted traction[27]. However, the confined working space through a single port increases the risk of instrument crowding and collision, necessitating greater bimanual coordination and spatial awareness[28]. Although the complication profile of SILS largely parallels that of conventional LC, it may be associated with higher rates of incisional infection and incisional hernia[28].

Robot-assisted surgery, with articulated arms, three-dimensional visualization, and a stable platform, may partially mitigate handedness constraints and instrument crossing in mirror-image anatomy[29]. Analyses of large databases, such as the National Surgical Quality Improvement Program, suggest that robotic cholecystectomy may be associated with fewer severe complications, lower conversion rates, and shorter hospital stays[30]. In addition, robotic systems readily integrate with indocyanine green fluorescence imaging, enabling three-dimensional delineation of biliary and vascular structures and potentially enhancing the safety of Calot’s triangle dissection for patients with SIT[31,32]. Available reports suggest that SILS and robot-assisted surgery are safe and feasible; however, the current evidence is largely limited to a small number of case reports. Both techniques involve a steep learning curve, require specialized instrumentation, and entail substantial technical and financial costs, which largely restrict their use to specialized centers[29]. Robust comparative evidence vs conventional multiport laparoscopy remains scarce. Consequently, SILS and robot-assisted surgery should be considered advanced technical alternatives for selected cases rather than routine standard procedures for patients with SIT.

Therefore, establishing an ergonomic and cognitively stable surgical approach for patients with SIT that minimizes the dependence on surgeon handedness and reduces the need for frequent positional adjustments remains a central challenge in LC. In this context, selection of the dissection pathway is a modifiable strategy to improve the exposure and operative workflow under mirror-image conditions. In this report, the “posterior approach” refers to a posterior-first dorsal route to Calot’s triangle, initiated by beginning dissection in the posterior plane, creating a posterior window, and proceeding along the dorsal plane in a posterior-to-anterior direction until the cystic structures are clearly delineated. This is best understood as an access strategy to Calot’s triangle rather than a distinct operation. Conceptually, it differs from fundus-first dissection, which begins at the gallbladder fundus and proceeds caudally along the liver bed and is commonly used as a bail-out option when Calot’s triangle is hostile[33]. In contrast, the posterior approach emphasizes earlier and more verifiable exposure through a dorsal dissection plane to facilitate identification of the cystic duct and cystic artery. It also differs from the classic infundibular approach, which relies on circumferential dissection around the infundibulum to identify an apparent cystic duct-infundibulum junction; this visual “funnel” may be unreliable in the context of marked inflammation or edema[34]. Finally, it differs from subtotal cholecystectomy, a bail-out option that intentionally leaves part of the gallbladder wall or stump when safe identification cannot be achieved[33,35]. The intent of the posterior approach is to support anatomic confirmation and attainment of the critical view of safety when feasible while maintaining readiness to escalate to bail-out strategies if anatomy remains uncertain. Compared with an anterior-dominant strategy, a posterior dissection pathway to Calot’s triangle may provide a more predictable sequence of exposure in a mirror-image field, potentially reducing instrument crossing and repeated reorientation. Because mirror-image anatomy can conflict with operative habits and cognitive schemas developed under conventional anatomy, an anterior-first trajectory may, in some challenging settings, be more susceptible to ergonomic inefficiency or perceptual mismatch; however, robust comparative evidence is lacking. Accordingly, we employed a posterior approach to Calot’s triangle as the core strategy in this case, on the basis of its anatomical rationale and ergonomic and cognitive plausibility, with the aim of facilitating clear anatomic confirmation rather than implying superiority in safety outcomes.

Anatomically, the posterior approach has a clear safety rationale. Prior studies indicate that the cystic artery typically runs superomedial to the cystic duct and lies predominantly in the anteromedial portion of Calot’s triangle[36]. In contrast, the posterior triangle is relatively distant from critical vascular structures, including the cystic artery and right hepatic artery, and its loose connective tissue may facilitate the development of a safer dissection plane[37]. Prioritizing dissection along this plane during LC may help minimize the risk of injury to anterior vascular structures. Related evidence further suggests that, in difficult cases, a posterior approach may shorten the operative time and reduce bleeding without increasing the rate of bile duct injury[37], thereby providing an anatomical and clinical rationale for its use in SIT.

Operationally, a posterior approach may improve ergonomics in SIT. Under a conventional anterior approach, instrument crossing and nonphysiological torsion can occur, potentially destabilizing fine manipulation and compromising ergonomic efficiency[17,18]. In contrast, a posterior pathway can permit a more parallel instrument trajectory toward the target area, which may better match right-handed motor patterns, reduce spatial interference, and improve stability and precision. These features may be particularly beneficial in mirror-image anatomy, where repeated reorientation can increase technical difficulty and reduce operative controllability.

More critically, a posterior approach may mitigate the cognitive spatial orientation conflict imposed by mirror-image anatomy. Available evidence indicates that major surgical errors may arise more commonly from cognitive misperception than from technical failure[38]. An anterior-first strategy may require early engagement with the most variable and complex anatomy, potentially increasing the cognitive load. In contrast, a posterior pathway allows dissection to begin in a relatively consistent tissue plane, establish a stable visual reference, and progressively confirm key structures along a posterior-to-anterior route, which may facilitate cognitive recalibration. A posterior perspective on the cystic duct, cystic artery, and adjacent structures may further support multiangle confirmation of biliary anatomy and complement the critical view of safety; nonetheless, critical view of safety verification remains essential regardless of the approach used.

Previous strategies for LC in SIT have largely focused on modifying external factors, such as surgeon position and instrument configuration. In contrast, a posterior approach to Calot’s triangle modified the dissection pathway and operative logic, potentially providing a more stable and predictable sequence of exposure in a mirror-image field and reducing the dependence on surgeon handedness and spatial reorientation.

Although the evidence base for LC in patients with SIT is largely limited to case reports and small case series, several recurring perioperative consideration domains have been described in the published literature. First, mirror-image anatomy may complicate symptom localization and radiological interpretation[39]. Accordingly, reports commonly emphasize targeted preoperative imaging to confirm SIT and to evaluate visceral orientation and biliary anatomy[23,29]. Second, SIT-associated cardiopulmonary conditions (e.g., Kartagener syndrome or congenital heart disease) may increase anesthetic complexity[1]. The literature therefore often recommends focused cardiopulmonary assessment and an appropriate airway management plan[12]. Third, SIT-LC introduces ergonomic and cognitive challenges in a mirror-image operative field, including counterintuitive hand-eye coordination and potential instrument interference[40]. Reported mitigation strategies include adopting a team-familiar operating room layout, optimizing the port configuration, and adjusting the position of the surgeon to accommodate the mirrored view[6,19]. From a safety perspective, SIT-LC can be regarded as a technically demanding variant of conventional LC, with higher requirements for spatial orientation and bimanual coordination[15]. Accordingly, SIT-LC is preferably performed by surgeons who are already proficient in conventional LC and who routinely apply safe identification principles, including attaining the critical view of safety and timely initiation of established bail-out strategies when anatomy remains uncertain[41]. For surgeons early in the LC learning curve, SIT-LC is generally not an ideal introductory case. We propose a pragmatic case-selection strategy that prioritizes patients with preoperatively confirmed SIT and imaging information sufficient to support operative planning. When the biliary anatomy is unclear, concomitant choledocholithiasis is suspected, or severe inflammation is anticipated, additional CT and/or MRCP may be considered to refine the preoperative assessment; if the anatomy still cannot be reliably identified intraoperatively, the threshold for initiating bail-out strategies or conversion to open surgery should be lower[33].

This study has several limitations, including substantial heterogeneity across published case reports and case series, small subgroup sample sizes, and incomplete reporting of key variables. Accordingly, all pooled quantitative summaries, including complication rates, should be interpreted as descriptive, as-reported patterns rather than population-level incidence estimates. Because the evidence is largely derived from case reports and small case series, the findings are inherently vulnerable to publication bias, with uneventful or technically successful cases more likely to be reported. The literature is also affected by selective outcome reporting and inconsistent documentation of perioperative endpoints. Missing data were not imputed, and denominators therefore varied across outcomes. Diagnostic labels and classifications were frequently author defined and non-standardized across reports. For example, “acute” vs “chronic” cholecystitis is variably defined on the basis of clinical presentation, imaging findings, or pathological criteria. These factors further limit comparability and preclude robust between-group inference. While this single-case outcome is encouraging, it should be interpreted as illustrative rather than confirmatory. Accordingly, our experience suggests that a posterior approach may be a practical option in patients with SIT when it facilitates anatomic clarification and ergonomic workflow rather than being superior. In addition, the concept of “relative posterior safety” is not absolute: Important vascular variants, including right hepatic artery variations, may still course near the posterior aspect of the cystic duct within the posterior triangle[42]. Therefore, meticulous sharp and blunt dissection under direct vision remains essential, and blind manipulation should be avoided[43]. Overall, a posterior approach to Calot’s triangle may be a useful technical option for addressing the anatomic and cognitive challenges of SIT. In the setting of a difficult Calot’s triangle, severe inflammation, or fibrosis, surgeons should avoid rigid adherence to an anterior-first strategy and instead consider a posterior pathway as a viable alternative, adapting the dissection sequence while prioritizing safe anatomic identification to maintain procedural stability and controllability.

CONCLUSION

LC in patients with SIT is feasible but technically demanding, particularly when inflammation or dense adhesions obscure Calot’s triangle. In this case, a posterior approach to Calot’s triangle enabled clear anatomical identification and safe dissection, leading to a successful procedure without perioperative complications. Combined with the reviewed literature, our experience indicates that thorough preoperative imaging, flexible operative planning, and awareness of a posterior dissection pathway as one possible strategy may help surgeons navigate mirror-image anatomy. Larger case series are needed to further evaluate the indications, limitations, and reproducibility of this approach.

ACKNOWLEDGEMENTS

We sincerely thank the patients and their families for their cooperation throughout data collection, treatment, and follow-up. We also acknowledge the authors of the cited literature, whose prior work provided an essential foundation for this study.