True benefit or selection bias: an analysis of laparoscopic versus open splenectomy from the ACS-NSQIP

By virtue of the benefits associated with minimally invasive approaches, laparoscopic splenectomy (LS) is believed to have better patient-related outcomes compared to open splenectomy (OS). However, there are limited data directly comparing the two techniques. Patients who underwent elective LS and OS between 2005 and 2010 were identified from the public use file of the ACS-NSQIP database using the Current Procedural Terminology codes 38120 and 38100. Patients who had concomitant procedures were excluded. Because of the nonrandom assignment of surgical techniques, a selection bias could have been responsible for the differences in patient outcomes. Therefore, patient characteristics and comorbidities that were available and could have been potential confounders were compared and regression analysis was performed to determine independent risk factors associated with serious and overall morbidity as well as mortality. During the study period 1,644 and 851 patients underwent LS and OS, respectively. Compared to patients who underwent LS, patients who had OS had a longer median length of hospital stay (3 vs. 6 days, P < 0.0001) and higher incidences of serious (7 vs. 17 %, P < 0.0001) and overall morbidity (12 vs. 25 %, P < 0.0001) and mortality (1.4 vs. 3.3 %, P = 0.02). However, there were certain significant differences in the characteristics and comorbidities of the patients that could have confounded outcomes. On regression analysis, OS was not associated with higher mortality (OR = 1.43, 95 % CI 0.7-2.7, P = 0.28) but was associated with higher serious morbidity (OR = 1.8, 95 % CI 1.4-2.3, P = 0.001) and overall morbidity (OR = 2.0, 95 % CI 1.6-2.4, P = 0.0001). After adjusting for available confounders, patients who underwent LS had lower morbidity and similar mortality rates. Although certain confounders such as previous surgical history, underlying pathology, and spleen size could still have potentially influenced outcomes, the data suggest that patient outcomes after LS are excellent and when technically possible a minimally invasive technique should be the preferred approach for splenectomy.