Hemobilia: a rare complication after routine liver biopsy during gastric bypass

Decision Tree for the Performance of Intraoperative Liver Biopsy During Bariatric Surgery

BACKGROUND AND AIMS

Bariatric surgery provides a useful opportunity to perform intraoperative liver biopsy to screen for non-alcoholic steatohepatitis (NASH). There is currently no consensus on whether intraoperative liver biopsy should be systematically performed. The aim of this study was to develop and validate a decision tree to guide that choice.

APPROACH AND RESULTS

This prospective study included 102 consecutive patients from the severe obesity outcome network (SOON) cohort in whom liver biopsy was systematically performed during bariatric surgery. A classification and regression tree (CART) was created to identify the nodes that best classified patients with and without NASH. External validation was performed. Seventy-one biopsies were of sufficient quality for analysis (median body mass index 43.3 [40.7; 48.0] kg/m²). NASH was diagnosed in 32.4% of cases. None of the patients with no steatosis on ultrasound had NASH. The only CART node that differentiated between a "high-risk" and a "low-risk" of NASH was alanine aminotransferase (ALT). ALT>53IU/L predicted NASH with a positive predictive value (PPV) of 68% and a negative predictive value (NPP) of 89%, a sensitivity of 77%, and a specificity of 84%. In the external cohort (n=258), PPV was 68%, NPV was 62%, sensitivity was 27%, and specificity was 90%.

CONCLUSIONS

The present work supports intraoperative liver biopsy to screen for NASH in patients with ALT>53IU/L; however, patients with no steatosis on ultrasound should not undergo biopsy. The CART failed to identify an algorithm with a good sensitivity to screen for NASH in patients with ultrasonography-proven steatosis and ALT≤53IU/L.

Comparative analysis of short-term outcomes after bariatric surgery between two disparate populations

BACKGROUND

Risk adjustment is a critically important aspect of outcomes research. Racial, geographic, cultural, and socioeconomic differences are nonclinical parameters that can affect clinical outcomes measurement after gastric bypass surgery.

METHODS

A single surgeon's experience with 217 consecutive laparoscopic gastric bypass patients in private practice in Southern California was compared with the same surgeon's experience with 124 consecutive patients in an academic institution in Philadelphia.

RESULTS

Of the Southern California and Philadelphia groups, 89%, 1%, 9%, and 1% and 55%, 38%, 6%, and 0% were white, black, Hispanic, and Asian, respectively. The average number of co-morbidities was 7.8 in the Southern California group versus 14.4 in the Philadelphia group (P <.001). The 60-day readmission to the hospital rate and emergency room admission rate was 1.4% versus 10.4% and 1.4% versus 18.5%. The insurer mix of private pay, private insurer, and federally funded insurer was 20%, 80%, and 0% in the Southern California group and 0.8%, 71%, and 28% in the Philadelphia group, respectively. Multivariate logistic regression analysis found Medicaid status and practice location independently predicted for the 60-day readmission rate (odds ratio [OR] 3.7, P = .04 and OR 5.6, P = .04, respectively) and a return to the emergency room (OR 3.2, P = .03 and OR 16.3, P <.001). Race, income, and the presence of diabetes were not independent predictors. Variables with nonsignificant differences between the Southern California and Philadelphia cohorts included average age, average body mass index, and major complications (return to surgery and intensive care unit admissions).

CONCLUSION

The results of this study have shown that in comparing and predicting the outcomes after bariatric surgery, adjustment for demographic and insurance variables might be necessary to improve accuracy.