Increasing use of laparoscopy over the past 3 decades has led to an increasing number of reports on adverse events attributed to such procedures. The most commonly reported complications include visceral injury (bowel/urinary tract), vessel injury, gas embolism, and subcutaneous emphysema [1].

The development of ascites after laparoscopic surgery has multiple aetiologies (i.e., unrecognised bowel or urinary tract injury), each requiring a different treatment strategy. However, in a small number of patients no causative factor can be identified for the development of ascites despite investigating those patients extensively.

We present a rare complication of laparoscopic surgery, that of ascites of unknown origin following laparoscopic appendicectomy in a young female patient.

This was an unusual case of ascites developing within 24 hrs of laparoscopic appendicectomy for a noninflamed appendix with no evidence of peritoneal contamination. No definitive causative factor was identified in spite of performing a thorough postoperative biochemical and cytological analysis of the accumulated fluid. Following exploratory laparotomy and drainage of the accumulated fluid, no further intra-abdominal fluid accumulation occurred without further therapeutic intervention being given to the patient other than intravenous antibiotics. We attribute the development of ascites to an idiopathic allergic or inflammatory peritoneal reaction to the laparoscopic procedure.

The primary concern during exploratory laparotomy was to exclude a significant complication (bowel/urinary tract injury) that could have been caused by the initial laparoscopic procedure. Furthermore, we investigated the unexpected fluid accumulation further to exclude other causes of ascites (i.e., acute pancreatitis) that might not have been associated directly with the initial procedure.

Bowel injury is a common cause of postoperative peritoneal fluid accumulation following a laparoscopic procedure. In the literature, the estimated incidence of bowel injury is reported to be 0–0.5% with approximately half of the injuries occurring during entry into the peritoneum [1]. It is one of the most important complications of laparoscopic surgery as it is potentially life-threatening if not identified at the time of the operation [2–4]. If intraoperatively unrecognised, patients often develop nonspecific complaints such as fever, diarrhoea, and abdominal distension/pain, not exactly pointing to peritonitis leading to further delay of establishing the diagnosis [5]. In our patient, the laparoscopic ports were inserted under direct vision; the peritoneal fluid had a clear colour on exploratory laparotomy and fluid cultures were negative. Inspection of the large and small bowel was normal; therefore, bowel injury was an unlikely the cause for the development of ascites.

Iatrogenic injuries to the urinary tract represent a significant complication of surgery, especially following laparoscopic procedures [6, 7]. They are common causes of large postoperative fluid accumulation in the peritoneal cavity [8]. The estimated rate of bladder injuries ranges from 0.02 to 8.3%, with the majority of injuries occurring during hysterectomy operations. Intraoperative identification of such injuries can be challenging for the surgeon, with approximately half of the injuries not being recognised at the time of surgery [9]. Further assessment of the urinary tract in cases of suspected injury can be performed by means of retrograde pyelography or excretory urograms and serum urea and creatinine measurements [10]. The colour of the peritoneal fluid, the thorough inspection of the bladder during exploratory laparotomy, the absence of microscopic haematuria and the nonelevated serum creatinine level effectively ruled out the possibility of iatrogenic urinary tract injury in our patient.

Collection of chyle in the peritoneal cavity as a result of lymph duct injury is another complication of laparoscopic surgery especially in cases of extensive retroperitoneal surgery [11–13]. In such cases, the peritoneal fluid has a distinctive appearance attributed to its high lipid content. Such diagnosis was considered unlikely by the authors regarding this particular patient as the retroperitoneal space was not entered during the procedure and the biochemical composition of the ascitic fluid was not suggestive of chyle.

Acute pancreatic ascites was another possible explanation for the development of ascites in our patient; however, the low levels of serum amylase and ascetic-fluid protein essentially ruled out such diagnosis.

To date, evidence in the literature to suggest the possibility of peritoneal allergic or inflammatory reaction to agents used during laparoscopic surgery in cases where visceral injury or other pathology has not been identified is limited to isolated case reports [14–17]. All reports on the subject have been produced on patients undergoing gynaecological procedures. After performing a systematic search on MEDLINE and EMBASE, we did not identify any previous reports on the development of postoperative idiopathic ascites following laparoscopic appendicectomy or other gastrointestinal surgery. Previous reports have suggested the possibility of allergic reaction to chemical agents used during laparoscopy (antiseptic peritoneal lavage and methylene blue dye) [16, 17]. However, our patient was not administered any specific drugs during the operation and the colour of the ascites was such that made the diagnosis of bacterial ascites unlikely. This was supported by the negative fluid cultures. We speculate that some substances used during laparoscopy (carbon dioxide, light/heat, diathermy) have triggered an inflammatory response explained by the elevated white cell count and the moderate hypoproteinaemia of the ascitic fluid.