Patient data and perioperative characteristics
One hundred and fifteen patients were enrolled into our retrospective study. Four distal pancreatectomies were performed laparoscopically, and 111 as an open procedure. Their baseline characteristics and perioperative variables are shown in Table 1. There were no significant differences between patients’ demographics between the groups, except for the male-to-female ratio. As sex does not exert a confounding influence on stump closure selection or outcomes [16], propensity matching was not performed. Even if procedures with stapled pancreatic stump tended to have shorter operative time than procedures using a hand-sewn closing technique (median time 180 versus 210 min., p = 0.037), other perioperative variables did not differ among stump closure groups.
The distribution of pancreatic thickness as a function of pancreatic leak (CR-POPF or BL) occurrence and stump closure technique is shown in Fig.2. ROC analysis for pancreatic transection site thickness to predict pancreatic leak in both stapled and hand-sewn groups established the same optimal cut-off thickness value for both techniques, 13 mm (Fig.3). Therefore, the 13 mm cut-off was used to divide patients into the thin and thick pancreas group and to investigate the outcomes of each stump closure technique according to pancreatic tissue thickness.
Outcomes
Outcomes of this sub-group analysis are depicted in Table 2. The CR-POPF rate for the entire cohort was 33%, and did not differ between the stapler and hand-sewn group, when investigated irrespective of pancreatic thickness (OR, 0.71; 95% CI, 0.32-1.57; p = 0.426). Closure of a transection of a thin pancreas using a stapler was associated with a lower risk of CR-POPF than hand-sewn closure (OR, 0.06; 95% CI, 0.006-0.34; p=0.0002). Vice versa, stapled closure of a thick pancreas was associated with significantly worse outcomes than with a hand-sewn closure (CR-POPF OR, 6.75; 95% CI, 1.7-28.4; p=0.0023).
The overall 90-day mortality rate for the entire cohort was 2.6% (3/115 patients), with an extended resection being associated with all cases of mortality (OR ;95% CI, 2.96 – infinity; p = 0.0046), rather than stump closure technique (OR, 0.35; 95% CI, 0.006 – 6.9; p = 0.446). All three patients died after extended resection. All deaths were associated with POPF, followed by gastrointestinal anastomosis leakage in both cases of multivisceral resections or thrombosis of vascular reconstruction in the other case. The mortality rate was not significantly different between the thin and thick pancreas groups for either stapled or hand-sewn stump closures.
The morbidity after stapled and hand-sewn group, irrespective of parenchyma thickness, was similar (OR, 0.67; 95% CI, 0.28 – 1.57; p = 0.33). A difference between the two closures was, however, identified between the two thickness subgroups. In the thin pancreas group, the OR of morbidity was 0.22 (95% CI, 0.06 – 0.77; p = 0.008), whereas is in the thick group, all patients who underwent a stapled closure developed complications (OR 95% CI, 3.04 – infinity; p = 0.0012). The rate of severe complications did not differ neither in the overall cohort (OR, 0.85; 95% CI, 0.36 – 2.04; p = 0.695) nor in both thickness - subgroups (thin OR, 0.34; 95% CI, 0.09 – 1.32; p = 0.086; thick OR, 2.66; 95% CI, 0.73 – 9.95; p = 0.107, respectively). Overall, the rate of POPF and morbidity, as well as the LOS was significantly lower when a thin pancreas was stapled and a thick hand-sewn.
Univariate analysis of risk factors identified an association between pancreatic leak (CR-POPF or BL) risk and a parenchyma thickness at the site of transection ≥13 mm and transection beyond the pancreatic neck (Table 3.). On multivariate analysis, only a parenchyma thickness ≥13 mm was retained as an independent predictor of pancreatic leak (OR, 3.85; 95% CI, 1.26 – 11.8; p = 0.018).