Use of high-frequency electrical stimulation in gastrocutaneous fistula closure: a case report.

BACKGROUND: Gastrocutaneous fistula is a rare complication following Roux-en-Y gastric bypass, a commonly performed bariatric surgery. While most ECFs respond to conservative management, some do not close despite adequate nutritional support, infection source control, and drainage management. As such, the chronicity of these difficult-to-treat wounds can be physically and economically costly to patients. CASE REPORT: A 53-year-old female with a history of Roux-en-Y gastric bypass developed a gastrocutaneous fistula secondary to a perforated gastrojejunal ulcer, requiring immediate surgical intervention. After being discharged from the hospital, 37 days of conservative management and NPWT did not reduce the size of the fistula tract. To help control the patient's chronic abdominal pain and increase the rate of wound healing, the patient underwent treatment with HFES (20 kHz) delivered using a handheld transcutaneous electrical nerve stimulator. This electrotherapy was found to reduce the majority of the patient's pain within the first treatment session. The patient's fistula also began to decrease in size within 1 week of initiating treatment. CONCLUSION: This case report details the successful closure of a gastrocutaneous fistula after administration of HFES 3 times a week over the course of 25 days. The mechanism of action of HFES and its role in the wound healing process are also discussed.

Channel Behavior and Voltage Gating of a Cx43 Mutant Simulating Preconditioning.

Background: Ischemic preconditioning induces lateralization and dephosphorylation of Connexin 43 (Cx43). However, the Cx43 protein that remains at intercalated disks may be phosphorylated by casein kinase 1 (CK1) and protein kinase C (PKC), and both kinases provide cardioprotection from further ischemic injury. Here we explore the channel characteristics of a Cx43 mutant mimicking preconditioning by CK1 and PKC phosphorylation. Materials and Methods: Whole-cell patch-clamp recordings were performed in cells expressing the mutant Cx43pc (S325,328,330,368D, S365A-Cx43), and the connexin electrical behavior was analyzed at the single channel and macroscopic level. Results: Cx43pc hemichannels opened readily, whereas gap junctions channels displayed amplitudes between the wild-type and CK1 phosphorylated forms, and weaker voltage gating than either counterpart. Conclusions: Ischemic preconditioning and the ensuing phosphorylation of Cx43 by PKC may render junctional channels insensitive to transjunctional voltages, allowing the preservation of intercellular communication in ischemic conditions.