No abstract

Purpose As a classical xenotransplantation model, porcine kidneys have been transplanted into the lower abdomen of non-human primates. However, we have improved upon this model by using size-matched grafting in the orthotopic position. The beneficial aspects and surgical details of our method are reported herein. Methods Donors were two newborn pigs (weighting 5 to 6 kg) and recipients were two cynomolgus monkeys (weighting, approximately, 7 kg). After bilateral nephrectomy, kidneys were cold-transported in Euro-Collins solution. The porcine kidney was transplanted to the site of a left nephrectomy and fixed to the peritoneum. Results Kidneys transplanted to the lower abdomen by the conventional method were more susceptible to torsion of the renal vein (two cases). In contrast, early-stage blood flow insufficiency did not occur in orthotopic transplants of theleft kidney. Conclusions Size-matched porcine-primate renal grafting using our method of transplanting tothe natural position of the kidneys contributes to stable post-transplant blood flow to the kidney.

Background Plexiform neurofibromas (PNs) are highly vascularized and potentially malignant tumors. Surgical resection of a PN can be complicated by perioperative hemorrhagic events (PHE), including excessive intraoperative blood loss and postoperative hematoma at the surgical site. This study aimed to evaluate the predictive factors of PHE and the usefulness of preoperative embolization for PN. Materials and methods Consecutive surgical resections of 24 massive PNs in the body trunk with a maximum diameter [ 5 cm in 22 patients between January 2015 and December 2020 were reviewed. Patient demographics, laboratory analyses, MRI findings, preoperative transcatheter arterial embolization (TAE), and pathological findings were evaluated between PNs with and without PHE, which consists of intraoperative blood loss over 15% of their estimated total blood volume and/or postoperative hematoma requiring surgical intervention or blood transfusion. Results PHE was observed in 7 out of 24 PNs (29.2%), with 5 events of excessive intraoperative bleeding and 2 postoperative hematomas. The PHE group (n = 7) showed a significantly higher flow-void effect inside the tumor on preoperative MRI than the non-PHE group (n = 17) (P = 0.0186). Preoperative TAE was not associated with PHE occurrence for the 24 PNs; however, it significantly reduced the PHE risk by 12 PNs with a flow-void sign (P = 0.00126). Other characteristics showed no significant differences between groups. Conclusion The flow-void sign on MRI can be the only predictive factor of PHE in surgical resection for massive PNs in the body trunk. Preoperative TAE can reduce the PHE risk for PNs with a flow-void sign.

No abstract

Acquired choanal atresia is a rare complication of pharyngeal surgical interventions. Here, we report the case of a 72-year-old woman who was treated in our institution for acquired choanal atresia after failed previous treatments. We have excised the obstructing fibrotic scar tissue and then reconstructed the area using a mucosal local flap and free radial forearm flap transfer. Choanal stenosis caused by abnormal granulation was identified in the months after surgery; however, this was treated with endoscopic dilatation and steroid injections in the outpatient setting. No restenosis was identified 1 year after the operation. Postoperative evaluation of speech was satisfactory. Free flap transfer could be an option for refractory choanal atresia, and endoscopic dilatation with local steroid injections may be an effective method to treat postoperative restenosis.