Impact of gastric resection and enteric anastomotic configuration on delayed gastric emptying after pancreaticoduodenectomy: a network meta-analysis of randomized trials.

INTRODUCTION: Delayed gastric emptying (DGE) is frequent after pancreaticoduodenectomy (PD). Several RCTs have explored operative strategies to minimize DGE, however, the optimal combination of gastric resection approach, anastomotic route, configuration and the use of enteroenterostomy remains unclear. METHODS: MEDLINE, Embase and CENTRAL databases were systematically searched for RCTs comparing gastric resection (classic Whipple, pylorus-resecting, pylorus-preserving), anastomotic route (antecolic, retrocolic), configuration (loop gastroenterostomy/Billroth II, Roux-en-Y), and use of enteroenterostomy (Braun). A random-effects, Bayesian network meta-analysis with non-informative priors was conducted to determine the optimal combination of approaches to PD for minimizing DGE. RESULTS: Twenty-four RCTs, including 2526 patients and 14 approaches were included. There was some heterogeneity, although inconsistency was low. The overall incidence of DGE was 25.6 per cent (647 patients). Pylorus-resecting, antecolic, Billroth II with Braun enteroenterostomy was associated with the lowest rates of DGE and ranked the best in 35 per cent of comparisons. Classic Whipple, retrocolic, Billroth II with Braun ranked the worst for DGE in 32 per cent of comparisons. Pairwise meta-analysis of retrocolic versus antecolic route for gastrojejunostomy found increased risk of DGE with the retrocolic route (odds ratio 2.10, 95 per cent credibility interval (cr.i.) 0.92 to 4.70). Pairwise meta-analysis of enteroenterostomy found a trend towards lower DGE rates when this was used (odds ratio 1.90, 95 per cent cr.i. 0.92 to 3.90). Having a Braun enteroenterostomy ranked the best in 96 per cent of comparisons. CONCLUSION: Based on existing RCT evidence, a pylorus-resecting, antecolic, Billroth II with Braun enteroenterostomy seems to be associated with the lowest rates of DGE. PREREGISTRATION: PROSPERO submitted 23 December 2020. CRD42021227637.

Relationships between gastric slow wave frequency, velocity, and extracellular amplitude studied by a joint experimental-theoretical approach.

BACKGROUND: Gastric slow wave dysrhythmias are accompanied by deviations in frequency, velocity, and extracellular amplitude, but the inherent association between these parameters in normal activity still requires clarification. This study quantified these associations using a joint experimental-theoretical approach. METHODS: Gastric pacing was conducted in pigs with simultaneous high-resolution slow wave mapping (32-256 electrodes; 4-7.6 mm spacing). Relationships between period, velocity, and amplitude were quantified and correlated for each wavefront. Human data from two existing mapping control cohorts were analyzed to extract and correlate these same parameters. A validated biophysically based ICC model was also applied in silico to quantify velocity-period relationships during entrainment simulations and velocity-amplitude relationships from membrane potential equations. KEY RESULTS: Porcine pacing studies identified positive correlations for velocity-period (0.13 mm s-1 per 1 s, r2 =.63, P<.001) and amplitude-velocity (74 µV per 1 mm s-1 , r2 =.21, P=.002). In humans, positive correlations were also quantified for velocity-period (corpus: 0.11 mm s-1 per 1 s, r2 =.16, P<.001; antrum: 0.23 mm s-1 per 1 s, r2 =.55; P<.001), and amplitude-velocity (94 µV per 1 mm s-1 , r2 =.56; P<.001). Entrainment simulations matched the experimental velocity-period relationships and demonstrated dependence on the slow wave recovery phase. Simulated membrane potential relationships were close to these experimental results (100 µV per 1 mm s-1 ). CONCLUSIONS AND INFERENCES: These data quantify the relationships between slow wave frequency, velocity, and extracellular amplitude. The results from both human and porcine studies were in keeping with biophysical models, demonstrating concordance with ICC biophysics. These relationships are important in the regulation of gastric motility and will help to guide interpretations of dysrhythmias.