Frontoethmoidal encephaloceles: reconstruction and refinements.

Frontoethmoidal encephaloceles are herniations of the intracranial contents through a defect in the skull at the junction of the frontal and ethmoidal bones. They are generally classified as nasofrontal, nasoethmoidal, and naso-orbital, although there may be some overlap or multiplicity. The records of 35 patients treated for frontoethmoidal encephaloceles were examined. Of these, 12 cases with complete and accurate medical records were evaluated in detail. The successful correction of frontoethmoidal encephaloceles was shown to depend on the following: a detailed understanding of the pathological anatomy (such as interorbital hypertelorism rather than true orbital hypertelorism and the presence of secondary trigonocephaly), careful planning of the bone movements to correct these deformities, and attention to detail regarding the placement of scars, positioning of the medial canthi, and the nasal reconstruction. Avoiding the "long-nose" deformity often seen after repair should be a priority. In general, the authors recommend a one-stage repair with both a transcranial and external approach.

Patterns of radial dysmorphology with the VACTERL association in the adriamycin-exposed prenatal rat.

The VACTERL association is an acronym for a constellation of abnormalities affecting the spinal column, anus, heart, trachea, esophagus, kidneys, and limbs that are seen in newborns. It has been shown that prenatal rats exposed to Adriamycin demonstrate a similar series of anomalies. It is the aim of this study to characterize the spectrum of limb anomalies in this model. Female Sprague-Dawley rats (N = 18; 14 experimental and 4 control) were used. After mating, pregnant animals received intraperitoneal injections of Adriamycin (2 mg per kilogram) on days 6, 7, 8, and 9 of gestation. Fetuses were recovered on day 21 of gestation. Ten experimental litters (42 fetuses) and two control litters (18 fetuses) underwent skeletal staining with Alizarin Red S stain. Four experimental litters (N = 18) and two control litters (N = 17) underwent histological study including staining for vascular and neural structures. Upper limb anomalies were found in 45% of the experimental animals, all including either hypoplasia or bending of the radius. The ulna was involved in 37% of the affected limbs. There were no isolated ulnar deformities. There were no histological differences noted. The spectrum of upper limb anomalies seen in the Adriamycin-exposed prenatal rat closely approximates, in incidence and morphology, the upper limb deformities seen with the VACTERL association in children. It is a reliable model for use in additional studies of the embryological mechanism by which these defects arise.

A method for minimizing donor site complications of the radial forearm flap.

The great advantages of the radial forearm fasciocutaneous flap are offset by the dilemmas associated with its donor site. The most commonly encountered problems are the functional and cosmetic sequelae of skin graft loss with consequent exposure of volar forearm tendons, the superficial sensory branch of the radial nerve, and the radius. Techniques that minimize donor site morbidity are those that provide a well-vascularized bed for the protection of exposed tendon, nerve, and bone, and for the acceptance of skin grafts. A technique involving the mobilization of the flexor pollicis longus muscle belly in conjunction with the abductor pollicis longus with approximation to the flexor digitorum superficialis muscle belly provides stable, well-vascularized coverage of the radial forearm flap donor site, with reliable skin graft acceptance and no functional sequelae.

Plantar verrucous carcinoma following transmetatarsal amputation and renal transplantation.

Verrucous carcinoma is a rare, low-grade, well-differentiated squamous cell carcinoma that may occur anywhere on the skin. It is slow growing, enlarges relentlessly, and invades locally. Most cutaneous verrucous carcinomas are found on the plantar surface of the foot, and share many gross and histological characteristics common to the ubiquitous verruca vulgaris. It is not uncommon for verrucous carcinoma of the sole to be mistaken for the more common verruca plantaris. The case of a 53-year-old white male with plantar verrucous carcinoma following cadaveric renal transplantation, right popliteal-tibial bypass, and a right transmetatarsal amputation is presented. Treatment included reamputation followed by reconstruction with a free radial forearm fasciocutaneous flap. Verrucous carcinoma is a slow-growing but relentlessly invading tumor that is easily misdiagnosed. The extent of early resection is often inadequate. We must be aware that certain persistent "warts" may represent a form of cancer that is treated differently from common verrucae or other squamous carcinomas.

Venous microanastomosis with the Unilink system, sleeve, and suture techniques: a comparative study in the rat.

Multiple microvascular anastomotic techniques have been described with varying rates of success. This experimental study presents the results of a comparison of three types of venous microanastomotic techniques: the Unilink system, the sleeve technique, and the suture technique. Twenty male Sprague-Dawley rats, 40 femoral veins, were used for this study. In vivo observation and microvasculography demonstrated that patency rates between the Unilink system and suture techniques were comparable (p > 0.05) and were significantly superior to the sleeve anastomosis (p < 0.05). The anastomotic time for the sleeve technique was significantly shorter than for the suture technique (p < 0.001). Compared with suture and sleeve anastomoses, the anastomotic time employing the Unilink system was significantly the shortest (p < 0.001). The Unilink system proved to be the fastest method with the highest patency rate. These results suggest that the use of the Unilink system is superior with regard to anastomotic time and patency rate, when compared to suture and sleeve techniques for venous microanastomosis.

Selective use of preoperative lower extremity arteriography in free flap reconstruction.

Preoperative angiography is commonly utilized prior to free flap reconstruction of the lower extremity. The charts and radiographs of 38 patients who underwent free flap reconstruction, after acute posttraumatic lower extremity injuries, were studied. Patients were categorized according to the presence or absence of vascular abnormality based on pulse examination alone. Specific vascular abnormalities were recorded in each group. Of the 38 patients who had preoperative lower extremity arteriography, 23 were found to have normal dorsalis pedis and posterior tibial pulses. Only 1 of these patients had an angiographic abnormality. Of the 15 patients with abnormal pulse examinations, all were found to have angiographic abnormalities. Cost analysis of the lower extremity angiogram revealed a total additional expense of $2,957. Pulse examination was found to be a sensitive and effective predictor of lower extremity vascular integrity. Although lower extremity angiography is encouraged when distal pulse examination is abnormal, the use of preoperative arteriography for lower extremity microvascular free flap reconstruction is probably unnecessary in most patients with normal distal pulses.

Axonal regeneration through an autogenous nerve bypass: an experimental study in the rat.

Neuroma-in-continuity can manifest itself not only as pain but also as incomplete return of motor and sensory nerve function. The mainstay of current treatment for peripheral neuromas employs neurolysis or segmental resection with interposition grafting. These techniques are complicated by the loss of the remaining conduction through intact fibers within the injured segment. Based on the recent finding that end-to-side neurorrhaphies demonstrate axonal growth, we studied the use of a nerve "bypass" graft as a possible alternative to neurolysis or segmental resection with interposition grafting. A sciatic nerve crush injury model was induced in the Sprague-Dawley rat by compression with a straight hemostat. Epineurial windows were created proximal and distal to the injury. An 8-mm segment of radial nerve was harvested and anastomosed to the sciatic nerve at the epineurial window sites proximal and distal to the compressed segment (bypass group). A sciatic nerve crush injury without bypass served as a control. Electrophysiological testing and gate studies were performed over an 8-week period. Sciatic nerves were then harvested en bloc and studied under transmission electron microscopy at 1250 times magnification. Myelinated and unmyelinated axon counts were obtained. Nerve conduction velocity in the bypass group was significantly faster than conduction velocity in the control group at 8 weeks (44.8 m per second vs. 36.4 m per second; p = 0.031). We found no difference in myelinated axon counts between the proximal and distal segments of the control sciatic nerve. In the experimental sciatic nerve, a 160% increase in the number of myelinated axons was noted in the distal segment. Significant axonal growth was noted in the bypass nerve segment itself. Gait analysis using the sciatic functional index revealed improved function of the bypass group compared to the control group, but this was not statistically significant. Nerve bypass may serve to augment peripheral axonal growth while avoiding further loss of the native nerve.

Fate of free flap microanastomosis distal to the zone of injury in lower extremity trauma.

The decision to perform free flap microanastomosis to clearly uninjured vessels proximal to the zone of injury for lower extremity reconstruction must be weighed against the anatomic and technical difficulties of performing such an anastomosis. Preserved blood flow through vessels traversing the zone of injury has been shown. The records of all patients who underwent lower extremity reconstruction with microvascular free flaps at NYU Medical Center and Bellevue Hospital Center from January 1979 through August 1995 were reviewed. Patients with free flap microanastomoses distal to the zone of injury were compared with those with proximally based anastomoses. The group of patients was subdivided further into acute (1-21 days), subacute (22-60 days), and chronic (greater than 60 days) reconstruction groups. Of 451 microvascular free flaps, 35 were performed with recipient vessels distal to the zone of injury. Time interval from injury to coverage ranged from 24 hours to 57 years. Of 35 distally based flaps, 33 (94 percent) were successful and 5 required reoperation (14 percent). There was a similar incidence of thrombotic complications throughout all after-injury phases. Of 416 free flaps performed with microanastomoses to vessels proximal to the zone of injury, 388 (93 percent) were successful and 62 (15 percent) required reoperation. There was no significant difference (p > 0.05) in outcome between distal and proximal anastomoses and no significant difference (p > 0.05) in rates of reoperation. Timing of operation after injury had no bearing on outcome. Distally based microvascular free flaps anastomoses may be technically less difficult with rates of survival equal to those of proximally based flaps. The consideration and use of microanastomoses distal to the zone of injury are encouraged in selected patients.

Use of epidural anesthesia and spontaneous ventilation during transabdominal colon and rectal procedures in selected high-risk patient groups.

PURPOSE: Patients with cardiopulmonary compromise who require transabdominal colon and rectal procedures are at increased risk for postoperative cardiac and pulmonary complications and prolonged hospital stays. Because epidural anesthesia has been shown to minimize reductions in functional residual capacity and consequently improve pulmonary function, we sought to determine its impact on patients undergoing colon and rectal procedures who were at high risk for postoperative cardiopulmonary morbidity. METHODS: We prospectively studied 31 patients undergoing colon and rectal procedures in whom epidural anesthesia with spontaneous ventilation were used. The criteria for entry included histories of respiratory insufficiency, atherosclerotic heart disease, and extremes of age. Patients who received general endotracheal anesthesia were excluded from consideration. Cardiac and pulmonary morbidity, mortality, and length of stay were analyzed. The data obtained were compared with those of a similar group of 50 patients who during the same time interval had undergone transabdominal colon and rectal operations with general anesthesia in the absence of epidural anesthesia. RESULTS: There were 19 males and 12 females in the epidural study group. Mean age was 71 (range, 35-92) years. There were no cases of pulmonary morbidity. Cardiac morbidity was 6 percent (2/31), with a mortality rate of 3 percent (1/31). Average length of postoperative hospital stay was 10.5 (range, 7-19) days. There were 29 males and 21 females with a mean age of 67 (range, 51-92) years in the general anesthesia group. Pulmonary morbidity was 18 percent (9/50). Incidence of cardiac complications was 4 percent (2/50). There were no mortalities. Average length of stay in the general anesthesia group was 13.6 (range, 6-24) days. CONCLUSION: Use of epidural anesthesia with spontaneous ventilation in elective transabdominal colon and rectal procedures may decrease the incidence of pulmonary complications and length of postoperative hospital stay in a select group of high-risk patients.

Thrombocytosis after major lower extremity trauma: mechanism and possible role in free flap failure.

Microvascular thrombosis and free flap failure are complications of free tissue transfer for coverage of lower extremity soft-tissue and bony defects despite appropriate vessel selection and adherence to meticulous technique. Increased rates of flap failure have been associated with reconstruction performed between 3 days and 6 weeks after injury, as well as in patients with thrombocytosis. We have found that serum platelet levels rise significantly after lower extremity injury. It is our theory that a circulating mediator or cytokine is released in response to injury, inducing the thrombocytosis. Twenty-one patients with Gustilo grade IIIb and IIIc injuries were studied prospectively. Serum was collected throughout the postinjury period. Platelet count, leukocyte count, hemoglobin concentration, and hematocrit were determined. Samples were also subjected to a platelet aggregation study as well as enzyme-linked immunosorbent assay for interleukin-3, interleukin-6, interleukin-11, and granulocyte macrophage-colony-stimulating factor. Megakaryocyte growth and development factor enzyme-linked immunosorbent assay and a myleoproliferative leukemia virus-transfected cell line assay for thrombopoietin were performed. Bone marrow was studied with flow cytometric analysis. Mean initial platelet count was 196,000 per cubic millimeter. There was an initial 26% decline to 140,000 per cubic millimeter, followed by an increase to 361% of baseline on day 16. No significant variations in serum leukocyte count or hemoglobin concentration were seen. Spontaneous and induced platelet aggregation responses were normal. Interleukin-6 was detected at elevated levels. However, interleukin-3, interleukin-11, granulocyte macrophage-colony-stimulating factor, and thrombopoietin were not measurable. Marked megakaryocytosis was seen on bone marrow analysis. Interleukin-6 may, therefore, play a role in the mechanism of thrombocytosis. We suggest that because patients with complex bony injuries of the leg experience platelet elevations that peak approximately 2 weeks after injury, microvascular free flap reconstructions should be considered high risk during this time period.

Central venous puncture versus cutdown for permanent pacemaker lead insertion: a modified double introducer technique.

OBJECTIVE: The comparative safety of central venous puncture versus cutdown technique for access to the right heart. EXPERIMENTAL DESIGN: A retrospective review of five hundred and fifty-five single and dual chamber permanent pacemaker implants performed between January of 1987 and December of 1993. SETTING: Review was performed at St. Vincent's Hospital in New York, New York and its teaching affiliate, Huntington Hospital, Huntington, New York. RESULTS: A total of 310 venous punctures were performed. The complication rate was 3.5% overall, with one procedure related death (0.3%) from major venous laceration; a stiff 14 French dilator sheath was employed in this case. There were no comparable complications in the 245 lead placements performed by various cutdown methods. CONCLUSION: Venous cutdown is a safe and effective method for placement of single and dual chamber pacemaker leads. If unsuccessful, the cephalic vein guidewire and double introducer techniques may be employed to rule out placement of dual chamber leads through a hypoplastic cephalic vein, using introducers not larger than 10 French. In properly selected patients, this technique could potentially prevent the complications associated with venous puncture.