Evaluation of diagnostic laparoscopy results in Turkish patients with unexplained ascites

Abstract

BACKGROUND

Diagnostic laparoscopy is a minimally invasive surgical method to diagnose intra-abdominal diseases.

AIM

To evaluate patients with unexplained ascites who could not be definitively diagnosed via advanced radiological and endoscopic methods and serological, cytological, and microbiological examinations and, therefore, underwent diagnostic laparoscopy.

METHODS

This retrospective analysis evaluated 82 patients who underwent diagnostic laparoscopy due to unexplained ascites. Patients’ medical records were obtained from the hospital database. Their age, sex, complaints at admission, laboratory results, radiological imaging results, diagnostic laparoscopy reports, and pathology reports were analyzed.

RESULTS

The serum-ascites albumin gradient was < 1.1 in 96.3% of the patients (n = 79). Among patients, 22 (26.8%) had benign diagnoses and 60 (73.2%) had malignant diagnoses. In addition, 55 (67.1%) were deceased, and the median follow-up time from diagnosis to death was four months. The overall follow-up time ranged from 1 to 142 months, with a median of 14 months. Patients’ diagnoses were significantly associated with their survival (P < 0.05, χ² test). The mortality rate was 86.7% among patients with malignant diagnoses and 13.6% among patients with benign diagnoses.

CONCLUSION

Diagnostic laparoscopy is minimally invasive, has a low complication rate, and requires a short hospital stay. It can be safely performed to diagnose and treat ascites that remain unexplained after advanced radiological and endoscopic examinations.

Key Words: Diagnostic laparoscopy; Ascites; Peritoneal thickening; Peritoneal tuberculosis; Survival

Core Tip: Diagnostic laparoscopy is minimally invasive, has a low complication rate, and requires a short hospital stay. Diagnostic laparoscopy has an essential role in diagnosing patients with ascites whose cause cannot be identified with advanced imaging modalities and endoscopic examinations. Most non-cirrhotic ascites are malignant and have a poor prognosis. Satisfactory results can also be achieved in treating ascites due to tuberculosis.

INTRODUCTION

Diagnostic laparoscopy (DL) is an endoscopic examination method that allows viewing more than two-thirds of the liver surface, gallbladder, spleen, falciform ligament, parietal peritoneal surface, serosal surfaces of the gastrointestinal system, and pelvic organs. It is a minimally invasive surgical method to diagnose intra-abdominal diseases[1]. It allows direct examination of large surface areas of intra-abdominal organs and facilitates obtaining biopsy samples, cultures, and aspirates. It facilitates the diagnosis of intra-abdominal disease and permits intervening in the disease[2]. It is indicated for acute and chronic abdominal pain, intra-abdominal mass, ascites, and liver diseases.

Since DL is minimally invasive, has a low complication rate, and requires a short hospital stay, it can be safely performed to diagnose and treat abdominal diseases that remain unexplained after advanced radiological and endoscopic examinations[3].

Ascites of unknown cause are among the most common indications for DL. The abdominal computed tomography (CT) findings of tuberculous peritonitis and peritoneal metastatic carcinoma are similar. DL and peritoneal biopsy are the preferred methods in patients with suspected peritoneal tuberculosis. DL is a rapid and accurate diagnostic test for tuberculous peritonitis[4].

DL is a minimally invasive surgical method used to diagnose intra-abdominal diseases. It allows direct examination of large surface areas of intra-abdominal organs and facilitates obtaining biopsy samples, cultures, and aspirates[5]. It facilitates the diagnosis of intra-abdominal disease and permits intervening in the disease. Ascites of unknown cause are among the most common indications for DL[6].

Few studies on DL have been conducted in Turkey to date. Therefore, this study aimed to evaluate patients with an intra-abdominal disease that could not be definitively diagnosed with advanced radiological and endoscopic methods and serological, cytological, and microbiological examinations and, therefore, underwent DL.

MATERIALS AND METHODS

This retrospective study evaluated 82 patients who underwent DL due to unexplained ascites and were followed up between January 2016 and June 2023 at two tertiary care centers: 50 patients at the Inonu University Turgut Ozal Medical Center and 32 patients at the Adiyaman Training and Research Hospital.

Inclusion criteria

The inclusion criteria were as follows: (1) Ascites without definitive diagnosis after comprehensive radiological, pathological, and microbiological evaluations; (2) Failure to obtain peritoneal fluid samples through interventional radiology; (3) Negative findings on upper and lower gastrointestinal endoscopy; and (4) A decision to proceed with DL for definitive diagnosis through tissue biopsy.

Preoperative radiological and laboratory assessments

All patients underwent the following diagnostic workups before DL.

Radiological imaging: Abdominal ultrasonography (USG), contrast-enhanced abdominal CT, abdominal magnetic resonance imaging (MRI), when clinically indicated.

Ascitic fluid analysis: Ascitic fluid samples were collected and analyzed for hemogram, albumin levels, and peritoneal culture. Ascitic fluid was cytologically evaluated. The serum-ascites albumin gradient (SAAG) was calculated for all patients.

Indications for DL

DL was indicated for patients with unexplained ascites without a definitive diagnosis after advanced radiological, interventional, pathological, and microbiological examinations. It was performed with the primary objective of obtaining tissue biopsies for histopathological examination.

Surgical procedure

The DL was performed under general anesthesia using the following standardized technique: A 1 cm-2 cm incision was made above the umbilicus, and a Veress needle was introduced to establish pneumoperitoneum with carbon dioxide. A 10-mm trocar was inserted at the umbilical site, and a laparoscope was introduced for intra-abdominal visualization. The abdominal cavity was systematically inspected, including the liver, spleen, omentum, peritoneum, ovaries, stomach, pancreas, and mesentery. Two additional 5-mm trocars were placed, and tissue biopsies were obtained from the peritoneum and omentum. If pathological findings were observed in other intra-abdominal organs, additional biopsies were taken from these sites.

Ethical considerations

All procedures were conducted according to the ethical standards of institutional and national research committees and adhered to the principles of the Declaration of Helsinki (1975, revised 2008). This study received ethical approval from the Non-Invasive Clinical Research Ethics Committee of the Inonu University Health Sciences on November 28, 2023 (Protocol No: 2023/5270). Written informed consent was obtained from all participants before their inclusion in this study.

Data collection and parameters analyzed

Patients’ data were retrieved from the hospital’s electronic medical records. The following parameters were analyzed: (1) Demographic characteristics, including age and gender; Presenting symptoms and clinical findings at admission; (2) Laboratory results, including hemogram and serum albumin; (3) Radiological imaging results, including USG, CT, and MRI; (4) DL findings and operative reports; and (5) Histopathological and microbiological results of tissue biopsies.

Statistical analysis

Statistical analyses were performed using SPSS Statistics for MacOS (version 29.0; IBM Corp., Armonk, NY, United States). Discrete variables are presented as the frequency (percentage), and continuous variables are presented as the mean ± SD or median (minimum-maximum). Nominal variables were compared using a two-tailed Pearson’s χ² test. A P < 0.05 was considered statistically significant.

RESULTS

This study evaluated 82 patients, of which 54 (65.9%) were females and 28 (34.1%) were male. The patients’ demographic and clinical characteristics are presented in Table 1. Their mean age was 58.0 ± 14.3 years, ranging from 18 to 87 years. The SAAG was < 1.1 in 79 (96.3%) patients. Among patients, 22 (26.8%) had benign diagnoses and 60 (73.2%) had malignant diagnoses. In addition, 55 (67.1%) patients were deceased.

Table 1 Baseline demographic findings of the study population, n (%).

Variables (n = 82)
Gender
Female	54 (65.9)
Male	28 (34.1)
Age
mean ± SD	58 ± 17
Median (minimum-maximum)	59 (18-87)
Serum ascites albumin gradient
< 1.1	79 (96.3)
≥ 1.1	3 (3.7)
Ascites cytology
Benign	29 (35.4)
Malignant	44 (53.7)
Inflammatory reaction	9 (11)
Final diagnosis
Malignant	60 (73.2)
Benign	22 (26.8)
Mortality
Deceased	55 (67.1)
Benign	27 (32.9)

The patients’ abdominal CT and DL findings are presented in Table 2. The most common abdominal CT finding was peritoneal adhesion with omental cake (n = 16, 74.4%), and the most common DL finding was intraabdominal adhesions (n = 59, 72.0%).

Table 2 Abdominal computerized tomography and diagnostic laparoscopy findings, n (%).

Radiological image
Peritoneal adhesion - omental cake	61 (74.4)
Peritoneal adhesion + ovarian mass	7 (8.5)
Liver mass	4 (4.9)
Diffuse intraabdominal lymphadenopathy	4 (4.9)
Ascites	3 (3.7)
Chronic liver disease	2 (2.4)
Peritoneal adhesion + diffuse intraabdominal lymphadenopathy	1 (1.2)
Findings of diagnostic laparoscopy
Intraabdominal adhesions	59 (72)
Intraabdominal adhesions + ovarian mass	11 (13.4)
Diffuse intraabdominal lymphadenopathy	3 (3.7)
Liver cirrhosis	3 (3.7)
Intraabdominal adhesion + diffuse lymphadenopathy	2 (2.4)
Gallbladder tumors + intraabdominal adhesions	1 (1.2)
Pancreatic mass + liver metastasis	1 (1.2)
Intraabdominal adhesion and pancreatic mass	1 (1.2)
Only ascites	1 (1.2)

The patients’ final diagnoses based on DL pathology findings are presented in Table 3. The most common pathology result was malignant mesothelioma (n = 22, 26.8%), followed by tuberculosis (n = 18, 22.0%) and ovarian cancer (n = 17, 20.7%).

Table 3 Patients’ final diagnoses and median follow-up times by diagnosis.

Last diagnosis	n (%)	Follow-up (months), median (minimum-maximum)
Malignant mesothelioma	22 (26.8)	2.5 (1-129)
Tuberculosis	18 (22)	87.5 (14-142)
Ovarian cancer	17 (20.7)	25 (3-95)
Stomach cancer	5 (6.1)	4 (3-12)
Colon cancer	4 (4.9)	19 (2-56)
Cryptogenic liver cirrhosis	3 (3.7)	96 (1-134)
Lymphoma	3 (3.7)	6 (1-69)
Pancreatic cancer	2 (2.4)	2 (1-3)
Gallbladder cancer	1 (1.2)	1 (1-1)
Cervix cancer	1 (1.2)	3 (3-3)
Cholangiocarcinoma	1 (1.2)	1 (1-1)
Neuroendocrine tumor	1 (1.2)	10 (10-10)
Gastrointestinal stromal tumor	1 (1.2)	40 (40-40)
Leiomyosarcoma	1 (1.2)	2 (2-2)
Duodenum adenocarcinoma	1 (1.2)	9 (9-9)
Churg-Strauss syndrome	1 (1.2)	10 (10-10)

Patients diagnosed with peritoneal tuberculosis were referred to the infectious disease clinic, and treatment for tuberculosis was initiated. Their ascites had improved at the end of the first month of tuberculosis treatment. Patients diagnosed with malignancy were referred to the medical oncology clinic.

The relationship between patients’ benign and malignant diagnoses and their survival is presented in Table 4. Patients’ diagnoses were significantly associated with their survival (P < 0.001, χ² test). The mortality rate was 86.7% among patients with malignant diagnoses and 13.6% among patients with benign diagnoses.

Table 4 Patients’ survival outcomes and follow-up characteristics, n (%).

Characteristic	Status		P value
	Alive	Deceased
Benign diagnosis	19 (86.4)	3 (13.6)	< 0.001
Malignant diagnosis	8 (13.3)	52 (86.7)
Time from diagnosis to death (months)
mean ± SD		18 ± 30.2
Median (minimum-maximum)		4 (0.5-129)
Follow-up period (months)
mean ± SD		33.7 ± 40
Median (minimum-maximum)		14 (1-142)

Patients’ time from diagnosis to death and overall follow-up time are summarized in Table 4. Their median follow-up time from diagnosis to death was 4 (0.5-129) months, and their median overall follow-up time was 14 (1-142) months. Patients’ time from diagnosis to death is summarized by diagnosis in Table 3. Those with cryptogenic liver cirrhosis and tuberculosis were followed for the longest time. The median survival time after diagnosis was 2.5 (1-129) months for patients diagnosed with malignant mesothelioma and 25 (3-95) months for patients diagnosed with ovarian cancer.

DISCUSSION

DL alone is not always sufficient for tumor staging. It is impossible to evaluate hollow organs, retroperitoneal lesions, and deep liver metastases laparoscopically. In these cases, endoscopic USG is used. Today, transabdominal USG over CT and angiography are preferred to DL due to their superiority in staging pancreatic and periampullary cancers[7]. However, DL has proven valuable in detecting liver and peritoneal spread of pancreatic and periampullary carcinomas. Laparoscopic USG permits determining tumor diameter and observing peripancreatic lymphadenopathy and invading vascular structures[8].

DL or mini-laparotomy is an essential diagnostic method preferred for early diagnosis in cases where tuberculosis is suspected. In addition to allowing visual evaluation of the peritoneum, it also permits taking a biopsy for histopathological examination. Laparoscopic imaging during the operation is approximately 95% accurate in diagnosis and may be superior to subsequent histological and microbiological examinations. Numerous white nodular structures are typically detected in the visceral and parietal peritoneum. Accompanying fibrous bands, adhesions, and omental thickening reinforce the diagnosis[9].

Ascites with unknown causes are among the most common indications for DL. Abdominal CT findings of tuberculous peritonitis and peritoneal metastatic carcinoma are similar. DL and peritoneal biopsy are the preferred methods in patients with suspected peritoneal tuberculosis. DL is a rapid and accurate test for tuberculous peritonitis[10]. A study conducted in South Korea involving 142 patients with ascites and peritoneal disease of unknown cause detected peritoneal tuberculosis in 52, peritoneal carcinomatosis in 46, and mesothelioma in 5[11].

In a DL series of 90 patients conducted in India, Amarapurkar et al[12] found abdominal tuberculosis in 36, malignancy in 13, diffuse or focal liver disease in 15, different causes in 19, and no cause in 5. In a DL series of 137 cases conducted in Spain, Porcel et al[13] found carcinoma in 51%, liver cirrhosis in 17%, liver mass in 11%, and abdominal tuberculosis in 4%. Our study detected cancer in 44 of the 82 evaluated patients (53.7%), consistent with Porcel et al[13]. In a series of 176 cases in China, Han et al[14] found peritoneal carcinomatosis in 99, tuberculous peritonitis in 31, liver cirrhosis in 19, and various causes in 27. In a series of 129 cases, Chu et al[15] found peritoneal carcinomatosis in 78, tuberculous peritonitis in 26, and liver cirrhosis in 7. Bedioui et al[16] reported detecting peritoneal tuberculosis in 56 patients and peritoneal carcinomatosis in 31 patients. DL findings may vary depending on countries’ development status. In underdeveloped countries or countries with high human immunodeficiency virus positivity, the most significant source of ascites of unknown origin may be abdominal tuberculosis[17]. In our patient series, malignant mesothelioma was the most common diagnosis, followed by tuberculosis and ovarian cancer. Notably, Türkiye is an endemic region for tuberculosis and mesothelioma[18].

In our study, SAAG values were compatible with the literature. One study reported that a SAAG of < 1.1 indicates non-portal ascites in 97% of cases[19]. However, it should not be forgotten that not every ascites case is due to liver cirrhosis, and not every cause is malignant if the SAAG is < 1.1. Mortality after diagnosis is very rapid for causes other than tuberculosis, and a satisfactory response may not always be obtained. The most critical issue for the patient is that at least a month is lost before ascites are noticed and DL is performed. It can take an average of two months for the patient to receive the final diagnosis.

CONCLUSION

DL is minimally invasive, has a low complication rate, and requires a short hospital stay. It can be safely performed to diagnose and treat ascites that remain unexplained after advanced radiological and endoscopic examinations. DL has an essential role in diagnosing patients with ascites without a definitive cause identified by advanced imaging modalities. Most non-cirrhotic ascites are malignant and have a poor prognosis. Satisfactory results can also be achieved in treating ascites due to tuberculosis.