The Effect of Radiation on the Patency of End-to-side Microvascular Anastomosis

Nowadays, more aggressive local control of primary cancer site is believed to be the most effective among the oncologists. However, this aggressive local control of cancer leaves a large defect of tissue which needs the reconstruction by a plastic surgeon.Post-oncologic reconstruction usually needs to use free flap coverage rather than local flap because of extensive tissue defect and post-radiation fibrosis. End-to-side microvascular anastomosis rather than end-to-end microvascular anastomosis is necessary especially for limb salvage in case of malignant cancer of the limb or for saving the important recipient vessel. The effect of radiation of end-to-end microvascular anastomosis was revealed to be minimal in the previous studies, but the effect of radiation on end-to-side microvascular anastomosis has not been researched up to present. The authors designed this experimental study model to clarify the effect of radiation on the patency of end-to-side microvascular anastomosis. For control group, total 20 rats were used. In one control group which consists of 10 rats, end-to-side microvascular anastomoses were carried out on their carotid arteries. In the other control group of 10 rats, end-to-end microvascular anastomoses were done. In radiation groups, 2000 rad X-radiation(peak 250 kV, 30 mA) was given on the neck areas of 40 rats. In two radiation groups, each of which consists of 10 rats, end-to-end and end-to-side microvascular anastomoses were carried out respectively on their carotid arteries 3 weeks after radiation. In another two radiation groups, each of 10 rats, the same procedures were done respectively 6 weeks after radiation. On the fourth week after anastomsis, the vascular patency and histological examinations were done. This study revealed that no effect of radiation on the vascular patency was found depending on both types of microanastomoses although some histologic changes were evident.

Complications after Open Reduction of Blow-out Fracture using Silicone Sheet

Many kinds of alloplastic implants have been used for surgical reconstruction of orbital wall fractures. Although complication rates caused by them are known to be higher than that by autologous grafts such as calvarian bone graft, there are few reports about collective cases for individual alloplastic implants. A retrospective review was performed on 115 patients who underwent orbital blow-out fractures reconstruction with silicone sheet(Silastic(R)) implants between 1989 and 1998. After the follow-up period from 1 month to 5 years, six patients(4.3%) had to undergo reoperations for implant removal because of complications such as infection, hematoma, displacement and extrusion of implant. Symptoms of Silicone sheet complications were progressive periorbital swelling, tenderness, proptosis, hypesthesia and persistant diplopia. Complications were diagnosed by history of Silicone sheet insertion, physical examination and follow-up facial bone or orbit CT. Mean duration of onset was 23.3 months. In all cases of complication, implants were surgically removed and proper antibiotics were used postoperatively. The symptoms subsided immediately without any other sequelae. The reconstruction of blow-out fractures with silicone rubber implant may cause serious late complications such as infection, displacement, hematoma, migration and extrusion. Therefore, careful follow up is nesessary, and prompt sheet removal should be considered first, if such complications are confirmed.