Nerve Switch for Reducing Synkinesis After Gracilis Muscle Transfer Innervated Via the Masseter Nerve.

BACKGROUND: In surgical treatment for longstanding facial paralysis, muscle transplantation is considered a useful and important method. To obtain a spontaneous smile, the use of the facial nerve of the healthy side as a motor source is better, but use of the masseter nerve allows prompt reinnervation and powerful movement. However, in some patients in whom the masseter nerve is used, separating masticatory movement and commissure contraction is difficult. Solutions for such patients have not been determined. CASE HISTORY AND DISCUSSION: A 46-year-old female patient presented with longstanding complete facial paralysis after resection of a right acoustic neurinoma. As initial surgery, free gracilis transfer was performed on the cheek, but the patient experienced commissure movement during meals postsurgery. Secondary corrective surgery was performed to detach the motor nerve of the gracilis from the masseter nerve and suture it to the facial nerve of the healthy side via cross-face nerve graft. The symptom improved but partially recurred. Improvement in synkinetic movement can be obtained by performing cross-face nerve grafting and subsequent nerve switch.

Back to the reinnervation of the pancreas after transplantation? (Experimental study on dogs, cats, and rats).

BACKGROUND: Significant functional decrease and sclerosis of the pancreas graft in late delays cannot only be related to chronic rejection. Any transplantation leads to graft denervation, which may be an important cause of dysfunction. Studies concerning graft reinnervation were controversial. PURPOSE OF THE STUDY: The purpose of this study was to investigate the feasibility and pertinence of a surgically directed reinnervation (SDR) of denervated/neuro-reflex isolated (NRI) or autotransplanted (aTx) pancreas. BASIC PROCEDURES: Anatomy of the nerves penetrating into the pancreas was studied in humans, dogs, cats, and rats. Surgery and physiological investigations were performed in dogs, cats, and rats. Nervous conductivity between NRI, NRI+SDR pancreas, and brain was tested. Load tests with glucose, insulin, and adrenalin were performed; amylase and lipase were determined in fasted and not fasted animals to evaluate the influence of NRI and SDR on pancreatic function. Histology was provided. Observation delays were 6 months. MAIN FINDINGS: Anatomic feasibility of SDR in humans and animals was proved. Models of pancreatic tail NRI and surgical reconstitution of the interrupted nervous pathways (SDR) were elaborated in animals. The restoration of the pancreas-brain reflex axis after SDR was electro physiologically proved. As blood glucose curves after load test, exocrine amylase and lipase determination have shown that pancreas NRI or aTx leads to an exaggerated reaction to usual stimulations that may cause the observed graft functional exhaustion in late delays. SDR shortened the period of the graft neuro-reflex isolation, contributed to a quick normalization of its function, and prevented its late degradation. CONCLUSION: SDR was shown to be a simple surgical technique, easily performed after the graft surgical revascularization. Its functional and morphological efficiency was tested and proved. Thus, SDR may be recommended in human pancreas transplantation as pertinent.