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Electromechanical reshaping (EMR) of cartilage is a novel technique that has significant potential for use in facial reconstructive surgery. EMR achieves permanent shape change by initiating electrochemical redox reactions in the vicinity of stress concentrations, thereby altering mechanical properties of tissue matrix. This study reports the use of a six electrode needle-based geometric configuration to reshape cartilage. Rectangular samples (24 x 12 x 1 mm) of rabbit nasal septal cartilages were bent at a right angle in a precision-machined reshaping jig. Two parallel arrays of three platinum needle electrodes were each inserted into cartilage along the bend at 3 mm from the bend line. One array served as an anode and the other as cathode. Constant voltage at 1, 2, 4, 6, and 8 volts was applied to the arrays for 2 minutes. The specimens were then removed from the jig and rehydrated for 15 minutes in phosphate buffered saline. Following rehydration, bend angles and thicknesses were measured. Bend angle increased with increasing voltage and application time. No statistically significant bending was observed below 6 volts for 2 minutes application time. Maximum bend angle of 33 ± 8 degrees or reshaping degree of 33% was observed at 8 volts applied for 2 minutes. Current flow was small (< 0.1 A) for each case. Sample thickness was 0.9 ± 0.2 mm. ANOVA analysis showed that cartilage thickness had no significant impact on the extent of reshaping at given voltage and application time. The six needle electrode geometric configuration conforms to the voltage-and time-dependent trends predicted by previous EMR studies. In the future, the reshaping properties of other geometric configurations will be explored.

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BackgroundObesity is a risk factor for pancreatic cancer which may be treated with Roux-en-Y gastric bypass and represents an increasing morbidity. Post-RYGB anatomy poses considerable challenges for reconstruction after pancreaticoduodenectomy (PD), a growing problem encountered by surgeons. We characterize specific strategies used for post-PD reconstruction in the RYGB patient.MethodsPubMed search was performed using MeSH terms “Gastric Bypass” and “Pancreaticoduodenectomy” between 2000 and 2018. Articles reporting cases of pancreaticoduodenectomy in post-RYGB patients were included and systematically reviewed for this study.ResultsThree case reports and five case series (25 patients) addressed PD after RYGB; we report one additional case. The typical post-gastric bypass PD patient is a woman in the sixth decade of life, presenting most commonly with pain (69.2%) and/or jaundice (53.8%), median 5 years after RYGB. Five post-PD reconstructive options are reported. Among these, the gastric remnant was resected in 18 cases (69.2%), with reconstruction of biliopancreatic drainage most commonly achieved using the distal jejunal segment of the pre-existing biliopancreatic limb (73.1%). Similarly, in the eight cases where the gastric remnant was spared (30.8%), drainage was most commonly performed using the distal jejunal segment of the biliopancreatic limb (50%). Among the 17 cases reporting follow-up data, median was 27 months.ConclusionReconstruction options after PD in the post-RYGB patient focus on resection or preservation gastric remnant, as well as creation of new biliopancreatic limb. Insufficient data exists to make recommendations regarding the optimal reconstruction option, yet surgeons must prepare for the possible clinical challenge. PD reconstruction post-RYGB requires evaluation through prospective studies.