Macroscopic Evaluation of Gastric Specimens After Laparoscopic Sleeve Gastrectomy-an Optimum Screening Test for Incidental Pathologies?

Histopathological Examination of 404 Sleeve Gastrectomy Specimens at a Large UK Center and Systematic Review of the Published Literature

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) specimens are histologically analyzed to identify incidental pathologies. However, no guidelines recommend routine histology. This study evaluates the clinical utility of LSG sample analysis and if incidental diagnoses have a significant clinical impact.

METHODS

A single high-volume UK bariatric unit retrospectively gathered LSG data covering a 9-year period. All specimens were sent for histological analysis. Where incidental diagnoses were identified, patient records were reviewed to assess any clinical management alterations. A systematic review (2013-2023) was performed, exploring rates of incidental pathologies post-LSG. Publications were stratified into those performing routine pre-operative endoscopy, or not, and results compared to present data.

RESULTS

From 01/06/2013 to 12/12/2022, 404 patients underwent LSG. 365/404 (90.4%) had no pathology on histopathological analysis. Seven (1.7%) appeared macroscopically abnormal, with histology identifying 3 polyposis and 1 each of GIST, pernicious anaemia, sarcoidosis and gastritis. Ten (2.48%) appeared macroscopically normal but had incidental pathology. All patient management remained unchanged. Twenty-two (5.44%) were H. pylori positive. Forty-eight publications within wider literature reviewed LSG specimen histology. Fifteen, including 9662 patients undergoing pre-operative endoscopy, found pathological diagnoses in 0.5% and 1 malignancy. Thirty-three studies reporting 17,008 patients without pre-operative endoscopy identified pathologies in 0.45% and 7 malignancies.

CONCLUSION

There is little clinical utility in analyzing macroscopically normal gastric samples following LSG. The potential financial and environmental savings from limiting this practice are of great importance to worldwide bariatric teams. The authors recommend selectively sending LSG specimens only if abnormal gastric mucosa is identified when examining the extracted specimen.

Frequency of Clinically Significant Findings in the Surgical Pathology Specimen Following Laparoscopic Sleeve Gastrectomy and Concordance with Preoperative Endoscopy: Insights from a Large Single-Center Experience

INTRODUCTION

Endoscopy prior to bariatric surgery is not always performed, and in sleeve gastrectomy (SG), the surgical specimen is not always sent for pathological examination. There is limited data on the frequency of clinically significant findings in SG specimens or correlation with preoperative endoscopy.

METHODS

We reviewed 426 consecutive SG patients to determine the concordance of preoperative endoscopy findings in patients with clinically significant postoperative pathology.

RESULTS

Preoperative endoscopy was performed on 397 patients (93.2%). Three hundred seventy-three patients had preoperative endoscopy and surgical pathology results available. Then, 20/373 (5.4%) patients had potentially significant postoperative pathology, including intestinal metaplasia, autoimmune metaplastic atrophic gastritis (AMAG), gastrointestinal stromal tumors, and/or gastric cancer. The overall incidence of AMAG in the entire cohort was 2.3%. Preoperative gastric biopsies (to include gastric body) identified AMAG in nearly 1/2 of patients. Patients with clinically significant postoperative pathology results had a median [interquartile range] of 3 [3-5] tissue blocks examined as compared to 3 [1-3] for the remainder of the cohort (p < 0.001).

CONCLUSION

This is one of the largest studies describing clinically significant postoperative pathology after SG. AMAG, in particular, is of particular importance as it is associated with a 3-fivefold increase in risk for gastric cancer. The incidence of significant postoperative pathology in this population is small but potentially clinically significant and requires validation in larger studies. We recommend wider sampling in preoperative endoscopy (body and antrum), especially in patients being planned for gastric bypass, consideration for routine pathological examination of SG surgical specimens, with careful gross examination and targeted sampling.

Compared to What? Is BMI Associated with Histopathological Changes in Laparoscopic Sleeve Gastrectomy Specimens?

BACKGROUND

Obesity is a risk for many different cancers. Laparoscopic sleeve gastrectomy (LSG) is common, and benign or pre-malignant histopathology types are reported in the removed gastric specimens. We assessed whether higher BMI was associated with certain benign or pre-malignant histopathological changes.

METHOD

Retrospective chart review of all primary LSG patients (N = 1555). Demographic, clinical, and LSG histopathology data were retrieved. BMI of patients with specific benign or pre-malignant conditions in their gastric specimens was compared with the BMI of the rest of the patients with abnormal histopathology specimens and also compared with the BMI of patients with normal control specimens.

RESULTS

Females comprised 70% of the patients. Mean BMI were 46.3 (females) and 48 (males). Normal LSG specimens comprised 52%. Most common abnormal histopathologies were chronic inactive gastritis (33%), chronic active gastritis (6.8%), follicular gastritis (2.7%), lymphoid aggregates (2.2%), intestinal metaplasia (1.4%) and GIST (0.7%). After controlling for confounders (age, gender, H. pylori, diabetes mellitus type 2, hypertension), no significant association was observed between the BMI of patients with specific benign or pre-malignant histopathology compared with the BMI of the rest of the patients with abnormal histopathologies and compared to the BMI of patients with normal histopathologies.

CONCLUSION

When confounders were taken into account, there appeared no significant associations between the BMI of patients with specific benign or pre-malignant histopathology compared with the BMI of the rest of the patients with abnormal histopathologies and compared to the BMI of patients with normal histopathologies of their gastric specimens. There was a very weak correlation between BMI and other covariates.