Lacrimal duct injuries revisited: a retrospective review of six patients.

This is a retrospective review of 6 patients treated for lacrimal duct injuries between December 1994 and October 1997. Four patients had inferior canalicular lacerations, one had a superior laceration, and one had a combined inferior and superior laceration. Associated injuries included facial fractures (1 patient), multiple facial lacerations (2 patients), and avulsion of the medial canthus (1 patient). All patients were repaired with Crawford tubes using a semicircular technique. The mean time of lacrimal intubation was 4.2 months (range, 3.6-4.5 months). One tube fell out at an undetermined time during the follow-up period. Visible anatomic restoration was considered excellent in all patients. There were no instances of persistent epiphora or other complications. Although there are several techniques available for treating lacrimal duct injuries in the course of dealing with general facial trauma, the semicircular technique using a Crawford intubation system yielded consistently reliable results with minimal or no complications.

The effect of a muscle wrap on nerve healing in a rat model.

Sixty Sprague-Dawley rats were studied to determine if peripheral nerve healing could be enhanced by translocation of an injured segment of sciatic nerve from an interfascial to an intramuscular environment. Group 1 (n = 12) were unoperated controls; Group 2 (n = 12) were sham-operated; Group 3 (n = 12) sustained an acute, double-crush injury to the sciatic nerve; and Group 4 (n = 12) sustained the same acute, double-crush injury as in Group 3, but the injured segment of nerve was transposed intramuscularly. All animals had sciatic function indices (SFI) computed at weekly intervals. At 2 weeks, Group 4 appeared to have improved gait function (SFI), compared to Group 3 (-39.7 vs. -56.4, p < 0.08). The experiment was repeated for Groups 3 and 4 using two groups of six additional rats each. The data were collected three times for each rat in the second experiment. No statistically significant differences in return of gait function or in nerve conduction evaluation could be demonstrated between the two study groups. From the results of this study, it appears that an intramuscular location does not enhance nerve recovery, compared to an interfascial location.

Anatomic study of the ulnar nerve and related vascular anatomy at Guyon's canal: a practical classification system.

Thirty-one fresh adult upper extremities were microdissected in order to delineate the regional anatomy of the ulnar nerve and artery at the wrist. Two patterns of division of the ulnar nerve trunk were identified: A and B. Three patterns of hypothenar muscle innervation-type 1, 2, and 3- and two patterns of vascular supply to the hypothenar musculature-type 1 and 2-were also identified. Pattern A occurred in 25 of the specimens where the ulnar nerve bifurcated into a main sensory trunk and a motor branch. Pattern B occurred in 6 of the specimens where the ulnar nerve trifurcated into two common digital sensory branches and a motor branch. The hypothenar innervation patterns were categorized as follows: type 1, 10 cases, single branch; type 2, 14 cases, two branches; and type 3, 7 cases, three or more branches. The patterns of hypothenar vascular supply were categorized as follows: type 1, 17 cases, major vascular arcade passing from the ulnar artery to the hypothenar musculature palmar to the entire ulnar nerve; type 2, 6 cases, arcade passing palmar to the motor portion of the nerve only; and type 3, 8 cases, no axial arterial supply identified. In no specimen did we identify a deep branch of the ulnar artery coursing with the deep motor branch of the ulnar nerve and contributing to a deep palmar arterial arcade. This classic description of a deep palmar arterial arch, we believe, is not valid, due to the mistaken identity of hypothenar arterial branches.

Effects of commonly used bowel preparations on the large bowel mucosal-associated and luminal microflora in the rat model.

Studies of colonic microflora have indicated there are two distinct populations, one intraluminal and one mucosal surface-associated. This investigation further characterizes the mucosal surface microflora and assesses the effects of common preoperative bowel preparations on both microflora. Quantitative and qualitative bacterial cultures and scanning electron microscopy were used to study the microflora in five groups of seven rats each: control; intraoperative colonic instillation of ten percent povidone-iodine for 20 minutes; mechanical preparation with magnesium citrate; mechanical preparation followed by intramuscular cefoxitin (30 milligrams per kilogram) one hour preoperatively; and mechanical preparation followed by oral neomycin sulfate and erythromycin base (15 milligrams/kilogram each) given by gavage tube 18, 14, and 4 hours preoperatively. Microflora on the mucosal surface was visualized by scanning electron microscopy in all groups except the neomycin/erythromycin group. Results showed fewer bacterial isolates recovered from the mucosal surface compared with the lumen, as well as several log10 units lower for each bacterial classification. The greatest suppression of both microflora was seen in the neomycin/erythromycin group. Total aerobic and anaerobic luminal counts decreased by 3.7 (P less than 0.009) and 6.3 (P less than 0.009) log10 units, while total aerobic and anaerobic wall counts decreased by 2.3 (P less than 0.009) and 2.8 (not significantly) log10 units, respectively. Lesser reductions were noted in the povidone-iodine group (P less than 0.009, P less than 0.009, P less than 0.009, and P less than 0.048, respectively). There were no statistically significant reductions in either total aerobic or anaerobic counts in the mechanical preparation or cefoxitin groups. These results indicate that neomycin/erythromycin is the most effective regimen in reducing both microflora.