Open versus minimally invasive management of gastric GIST: An international multi-institutional analysis of short- and long-term outcomes.

Abstract

85 Background: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the GI tract. Overall surgical experience with minimally invasive surgery (MIS) has increased, however, published reports on MIS resection of GIST are currently limited to small, single institution experiences. Methods: 397 patients who underwent surgical resection of a gastric GIST between 1998 and 2012 were identified from an international, multi-center database. The impact of the MIS approach on recurrence and survival was analyzed by the use of propensity-score matching by comparing clinicopathologic factors between patients who underwent open vs MIS resection. Results: Median patient age was 65 years and 50% were female. Median tumor size was 4.3cm (IQR 3.0-7.6cm). A minority of patients received neoadjuvant therapy (6%). Overall, 186 (47%) patients had a MIS approach: laparoscopic (89%), laparoscopic hand assist (4%), combined laparo-endoscopic (3%) and robotic (4%). There were 19 (10%) conversions to open; the most common reasons for conversion were tumor more extensive than anticipated (26%) and unclear anatomy (16%). Patients who underwent MIS resections had smaller tumors (MIS: 3.5cm vs open: 5.8cm; p<0.01). MIS resections were associated with minimal blood loss (MIS: 50 cc vs open: 225 cc) and shorter operative time (MIS: 160 min vs open: 201 min) (both p<0.01). There was no difference in rates of tumor rupture (MIS: 1.1% vs open: 0.9%; p=0.81). An R0 resection was achieved in the majority of patients (MIS: 98% vs open: 92%; p=0.07). MIS patients had a lower incidence of grade 3 or 4 complications (MIS: 3% vs open: 10%; p=0.01) and a shorter length of stay (MIS: 3d vs open: 8d; p<0.01). After propensity score matching for age, sex, tumor size, mitotic rate and tumor rupture, there was no difference in risk of recurrence or overall survival for the MIS treated group vs. the open group (HR 0.65 & HR 0.76, respectively; both p>0.05). Conclusions: An MIS approach for gastric GIST is associated with a low incidence of complications and a comparable R0 resection rate. The long-term oncological outcome following MIS is excellent and therefore the MIS approach should be considered preferable.