Choristomas of the seventh and eighth cranial nerves.

Choristomas, masses of normal tissues in aberrant locations, contain smooth muscle fibers and fibrous tissues. We describe the MR imaging features of two choristomas located in the internal auditory canals and arising from the facial and vestibulocochlear nerves. Both lesions enhanced with contrast material. In one case, enhancement was seen in the geniculate ganglion and greater superficial petrosal nerve. In the other, a medial component enhanced less than the lateral component did.     

Day surgery for laparoscopic repair of abdominal wall hernias

Laparoscopic repair of abdominal wall hernias is still a controversial and nongeneralized therapeutic option. The aim of this paper is to evaluate the results of laparoscopic surgery on abdominal wall hernias at a day-surgery unit and to describe our procedure protocol. Prospective analysis of 300 patients undergoing laparoscopic surgery for abdominal wall hernias was conducted: 260 preperitoneal and 40 intraperitoneal. The patients' clinical features, hernia type, intraoperative and postoperative complications, and follow-up are studied for both types of surgery. All the patients receiving surgery with extraperitoneal laparoscopy were completed as a day-surgical procedure with a rate of conversion to open surgery of 2.3%. Twelve (30%) of the 40 patients operated on for ventral hernias using intraperitoneal laparoscopy required hospitalization: five for perioperative complications and seven for pain (16%). There was no case of infection or mesh rejection. The recurrence rates were 0.78% (two cases) for the inguinal hernias and 2.5% (one case) for the ventral hernias. In conclusion, laparoscopic repair of abdominal wall hernias in a day-surgery setting is an efficient alternative to open surgery. Electronic Publication     

Modified cervical laminoforaminotomy based on anatomic landmarks reduces need for bony removal.

We describe a modified keyhole laminoforaminotomy (LF) using anatomic landmarks on the posterior aspect of the cervical vertebral body to decompress the intervertebral foramen with minimal bone removal. Twenty-four procedures were performed at C3-4, C4-5, and C5-6; 12 at C6-7; and 3 at C7-Tl. Facets and laminae structures were identified based on relative surgical perspectives. Bony resection was limited as follows: 1) inferior limit; inferior border of the superior facet; 2) superior limit, superior border of the superior facet; 3) lateral limit, a vertical line linking the junction of the lamina-facet to the lateral end of the superior limit; and 4) lateral aspect of the dural sac. Fluoroscopy was used to confirm that the intervertebral space was reached. The amount of bony removal was quantified for the superior and inferior laminae and facets. The length of the exposed nerve root was measured. The intervertebral foramen was exposed and the intervertebral disc reached in all specimens. Fluoroscopy showed that the center of the exposure remained at the same height with the intervertebral space. The mean length of the nerve root was 4.6 mm; the mean percentage of bony resection was 21.8%, 7.5%, 11.3%, and 11.5% for the superior and inferior laminae and facets, respectively. Opening the intervertebral foramen posteriorly consistently exposed sufficient nerve root length and allowed access to the intervertebral disc. The technique offers the most direct and safest method of decompressing the intervertebral foramen while minimizing bony resection. This simple surgical procedure may help reduce postoperative morbidity.     

A New Technique for CT/MR Fusion For Skull Base Imaging

This paper presents our initial experience utilizing a new technique which allows CT and MR image fusion in patients with skull base lesions. Eleven patients with a variety of skull base lesions underwent CT and MR imaging prior to surgery. Both sets of images were coregistered using customized software. The CT and MR data sets were then combined and viewed in a single interactive image formar using a high-speed graphic computing system. Image fusion allowed simultaneous visualization of the bony skull base anatomy (CT) and detailed soft tissue anatomy (MR) using a single image format. Combining both modalities was felt to provide a better assessment of the extent of lesions and improve understanding of their relationship to adjacent bony and neurovascular anatomy. Specifically, image fusion enhanced awareness of location of skill base lesions with respect to the cavernous sinuses. Gasserian ganglia, carotid arteries, and jugular foramina. For tumors arising within the internal auditory canal (IAC), fused images allowed better delineation of the lateral aspect of the lesion with respect to the fundus of the IAC. Thus, fusion of CT and MR studies provides a unique image format which has advantages over single modality display. We believe image fusion is beneficial for surgical planning and for treatment planning of complex skull base malignancies treated with radiotherapy.