The burden of abdominal pain after bariatric surgery in terms of diagnostic testing: the OPERATE study

BACKGROUND

Abdominal pain after bariatric surgery (BS) is frequently observed. Despite numerous diagnostic tests, the cause of abdominal pain is not always found.

OBJECTIVES

To quantify type and number of diagnostic tests performed in patients with abdominal pain after BS and evaluate the burden and their yield in the diagnostic process.

SETTING

A bariatric center in the Netherlands.

METHODS

In this prospective study, we included patients who presented with abdominal pain after BS between December 1, 2020, and December 1, 2021. All diagnostic tests and reoperations performed during one episode of abdominal pain were scored using a standardized protocol.

RESULTS

A total of 441 patients were included; 401 (90.9%) were female, median time after BS was 37.0 months (IQR, 11.0-66.0) and mean percentage total weight loss was 31.41 (SD, 10.53). In total, 715 diagnostic tests were performed, of which 355 were abdominal CT scans, 155 were ultrasounds, and 106 were gastroscopies. These tests yielded a possible explanation for the pain in 40.2% of CT scans, 45.3% of ultrasounds, and 34.7% of gastroscopies. The diagnoses of internal herniation, ileus, and nephrolithiasis generally required only 1 diagnostic test, whereas patients with anterior cutaneous nerve entrapment syndrome, irritable bowel syndrome, and constipation required several tests before diagnosis. Even after several negative tests, a diagnosis was still found in the subsequent test: 86.7% of patients with 5 or more tests had a definitive diagnoses. Reoperations were performed in 37.2% of patients.

CONCLUSION

The diagnostic burden in patients with abdominal pain following BS is high. The most frequently performed diagnostic test is an abdominal CT scan, yielding the highest number of diagnoses in these patients.

Pancreatic exocrine insufficiency after bariatric surgery

BACKGROUND

Chronic abdominal complaints after bariatric surgery may be explained by pancreatic exocrine insufficiency (PEI).

OBJECTIVES

We aimed to evaluate the clinical value of the Pancreatic Exocrine Insufficiency Questionnaire (PEI-Q) as a screening tool to identify patients with a high probability of having PEI.

SETTING

Outpatient clinic for bariatric surgery.

METHODS

Patients scheduled for a screening or follow-up appointment were asked to complete the PEI-Q and the Gastrointestinal Quality of Life Index questionnaire (GIQLI). Postoperative patients with a high PEI-Q score (0,6) were offered a fecalelastase (FE) test (abnormal if <200 μg/g).

RESULTS

Between June 2020 and February 2021, a total of 1600 of 1629 PEI-Qs were completed, 1073 (67%) of which after surgery. The postoperative group consisted mostly of females (81.9%), aged 49.0 ± 10.6 years, with a total weight loss of 30.3% ± 8.8%. Among them, 63.4% had abnormal PEI-Q scores compared with 34.9% before surgery (P < .01). In contrast, the median GIQLI score increased (119 [interquartile range (IQR), 107-129.25] versus 110 [IQR, 95-121.75]) before surgery (P < .01). Additionally, 310 FE tests were performed, of which only 11.9% was suggestive of PEI. No correlation was found between the PEI-Q scores and FE levels (c-index .55).

CONCLUSION

The PEI-Q in its current version is not able to distinguish complaints of PEI and bariatric surgery itself and therefore cannot be used as a screening tool for PEI. The specificity of the FE test seems to be reduced after surgery. Future research should include a more direct pancreatic function test, which may provide more insight into PEI after bariatric surgery.