Isolated musculocutaneous neuropathy caused by a proximal humeral exostosis.

We report an isolated musculocutaneous neuropathy caused by a proximal humeral osteochondroma that became symptomatic after the patient played recreational basketball. Lesion resection resulted in complete deficit resolution. Mass lesions involving the musculocutaneous nerve should be considered in patients with atraumatic, isolated musculocutaneous neuropathies that are recurrent or fail to recover, even in the setting of strenuous exercise.

Mechanical performance of a work hardened pointed surgical wire.

The design and material properties of a surgical wire have been enhanced to improve its performance in surgery. One blunt end of the wire has been honed to a point to decrease the axial compressive force required to penetrate tissue. In addition, its sharp end has been work hardened to increase its yield strength. The mechanical performance of this wire has been characterized by a series of in vitro experiments and a clinical trial.

Analysis of the kinetics of peritoneal adhesion formation in the rat and evaluation of potential antiadhesive agents.

BACKGROUND: Peritoneal adhesions continue to be a significant cause of postoperative complications. Elucidating the origin of these adhesions has been hampered by the lack of a reproducible animal model. The purpose of this study was to create a standardized model in which a single, specific adhesion could be objectively measured. With this model the kinetics of adhesion formation were then evaluated. A variety of potential antiadhesive agents were then tested and compared. METHODS: In this study a reproducible, quantitative rat model was developed that used uniform defects on the peritoneal wall and cecal surface. The resulting adhesions were subsequently scored, and their strength was measured with a tensiometer. An evaluation of the kinetics of peritoneal adhesion formation was obtained by using a timed removal of silicone elastomer sheeting held between the two injured surfaces. The following antiadhesive agents were evaluated: Ringer's lactate solution; dextran 70 (32%); modified carboxymethylcellulose (1.0% and 2.0%); an absorbable barrier of specially knitted material composed of oxidized regenerated cellulose; fibrin sealant; silicone elastomer film; and expanded polytetrafluoroethylene membrane. RESULTS: Evaluation of the kinetics of peritoneal adhesion formation indicated that the susceptibility for adhesion formation was significantly decreased or eliminated after the first 36 hours. Evaluation of antiadhesion agents indicated that the magnitude of adhesion prevention was directly proportional to the agent's ability to remain at the site of injury during the critical period of adhesion formation. Permanent barriers (silicone elastomer film, expanded polytetrafluoroethylene membrane) provided the greatest antiadhesion effect but were not believed to be ideal agents because they remained at the site of injury well after the critical period of adhesion formation. The incidence of adhesion formation for the other agents was as follows: control (34 of 34), Ringer's lactate (12 of 12), absorbable barrier of knitted cellulose (10 of 10), 32% dextran 70 (8 of 12), 1% carboxymethylcellulose (6 of 12), fibrin sealant (4 of 9), and 2% carboxymethylcellulose (4 of 12). CONCLUSIONS: The efficacy of antiadhesion agents appears to be related to the agent's viscosity, ability to coat the wound surface, and residence time at the site of injury. In this rat model an agent that remained on the injured surfaces for at least 36 hours after injury appeared to be more effective in reducing adhesion formation than an agent with a shorter residence time.

Seroma prevention using fibrin glue in a rat mastectomy model.

Seromas are a frequent complication of mastectomy (17% to 53%) in humans and are correlated to skin flap elevation, lymphovascular interruption, and drainage into surgically created potential spaces. The use of intraoperative topical fibrin glue to reduce morbidity in rats undergoing radical mastectomies has been evaluated. A model consistently producing seromas was developed by radical mastectomy and lymphadenectomy in the Sprague-Dawley rat. A fibrin glue application procedure was tested using this model. The double-blinded protocol called for spray application of saline or fibrin glue to mastectomy wounds followed by sequential inspection and necropsy on postoperative days 5, 8, 11, and 14. Topical fibrin glue was shown to be statistically significant in decreasing the presentation of seromas following a radical mastectomy in the Sprague-Dawley rat.

Gastrotracheal fistula: a late complication after transhiatal esophagectomy.

A 51-year-old woman underwent a transhiatal esophagectomy for a failed antireflux procedure. She did well for 15 months, when she developed evidence of hemoptysis followed by tracheogastric fistula. She underwent operative repair with the use of a pericardial patch to replace the membranous trachea and interposition of a latissimus dorsi flap to isolate the stomach from the tracheal suture line. She has done well after this operation.

Tracheal reconstruction with autogenous jejunal microsurgical transfer.

Tracheal defects due to stricture formation, tracheomalacia, and neoplasms can present difficult reconstructive problems. Tracheal defects were surgically created in 6 dogs and primarily reconstructed with microsurgical free tissue transfer of autogenous jejunal segments. Primary healing was accomplished in all dogs without severe air leakage or infection. Bronchoscopy demonstrated no substantial secretions or tracheal narrowing. Gross pathological examination of the trachea revealed no evidence of tracheal disruption or infection. Direct measurements revealed no major tracheal narrowing. Microscopic examination demonstrated normal jejunal mucosa with a minimal amount of inflammatory change at the margins of the reconstruction at 6 weeks. Microvascular free tissue transfer of jejunal segments to correct cervical tracheal defects can readily be accomplished with excellent healing and maintenance of the tracheal lumen in dogs.

The trapezius musculocutaneous flap in head and neck reconstruction: potential pitfalls.

Defects resulting from bulky tumor resection of the head and neck region represent a reconstructive challenge. The trapezius musculocutaneous paddle flap based on the transverse cervical vessels is a useful tool for the reconstructive surgeon. Failure to recognize the variable anatomy is discussed in relation to other musculocutaneous flaps used for the purpose of head and neck reconstruction. The trapezius muscle has a variably located vasculature and diverse nomenclature. The knowledge of the variance of its anatomical vasculature is essential in the successful use of the trapezius musculocutaneous flap.

Value of contralateral supraomohyoid neck dissections.

This study was carried out to determine the merit of contralateral supraomohyoid neck dissection in the clinically negative neck. When performed in conjunction with a standard radical neck dissection on the ipsilateral side, a yield of 2.8 percent pathologically positive nodes (5 of 177) was obtained in the contralateral neck. Little difference was noted in the yield of midline lesions versus unilateral lesions which approached the midline (3 and 2.6 percent, respectively). Similarly, the yield with preoperative radiation was close to that of the nonradiated group (3 and 2.7 percent, respectively). Additionally, in 1.7 percent of patients (3 of 177) with both clinically and pathologically negative nodes, metastases later developed in the contralateral neck, which indicates that the dissection is not necessarily effective in preventing future disease. The contralateral supraomohyoid neck dissection in the treatment of malignancies of the oral cavity, pharynx, and larynx does not appear to be of significant therapeutic value.

Early ambulation after skin grafting of depressed wounds of the leg.

Silicone molds can be fitted precisely to skin grafted, depressed surgical defects of the leg and can be secured in place with a tight-fitting elastic support. The gravitational effect and resultant edema under the skin graft can be reduced. Earlier ambulation and better results than have been reported in the past can be obtained.

Bacteriologic evaluation of electric clippers for surgical hair removal.

Clipper blade assemblies for electric clippers used repeatedly without sterilization demonstrated high levels of bacterial contaminations that are potential sources of infection. A technique of sterilization of the clipper blade has been reported that eliminates the exogenous bacterial contamination.

Galeal-pericranial flaps in head and neck reconstruction. Anatomy and application.

Head and neck deformities of congenital, traumatic, or neoplastic cause often require reconstruction. At the University of Virginia over the past 14 years, we have used galeal, temporalis fascial, and pericranial flaps to correct these defects in more than 150 patients. Dissection of these flaps on both cadavers and reconstructive patients had demonstrated new anatomic findings different from those reported in standard textbooks. The galea is the most superficial layer of fascia. The pericranium is the next tissue layer. It is continuous above and separate from the temporalis muscle fascia. We may, therefore, consider three separate fascial layers for reconstruction. A rich vascular plexus arises from branches of the external and internal carotid arteries. Blood flow is axial to the galea and temporalis fascia. Pericranium has a dual supply from peripheral axial vessels and from perforating vessels from the overlying galea. Galeal, temporalis fascial, and pericranial flaps are reliable, thin, and supple and have a good arc of rotation and minimal donor site morbidity. They may be used to cover bone, cartilage, or implants, may be folded for bulk, may be used to carry blood to poorly vascularized recipient sites, or may be used to nourish bone, cartilage, skin, and mucosal grafts. Their versatility permits a wide variety of potential applications in head and neck surgery.

Innovations in skin suture removal.

A cutting forceps and suture removal scissors have been specially designed for removal of percutaneous sutures. Our clinical experience with these instruments indicate that they facilitate removal of percutaneous sutures in the surgical patient.

Surgical management of vascular malformations of the head and neck.

The evaluation and treatment of non-involuting hemangiomas with arteriovenous components and arteriovenous malformations of the head and neck remain difficult. Surgical excision is still the most important and effective method of controlling these lesions. Radiotherapy should never be used. It is ineffective, dangerous, and often complicates any later operation that may be required. Evaluation of vascular malformations with computerized tomography, arteriography, magnetic nuclear imaging, and Doppler mapping will aid diagnosis. Adjunctive hypotensive anesthesia, intraoperative embolization with Gelfoam, and temporary peripheral suture ligations have made the surgical task more manageable. The integration of reconstructive techniques into the surgical program is essential if optimum results are to be obtained. Incisions must be planned so that future flap patterns are preserved. Axial vessels may be needed later. Fascial slings, muscle transfers, nerve grafts, and tissue expansion of adjacent normal tissue may be needed to maintain and restore function and features. Above all, the treatment of each patient requires individual planning. The most common errors in the treatment of vascular hemangiomas result from missed diagnoses and faint-heartedness in tackling the surgical removal of such highly vascular tumors. Many patients go for years without finding a surgeon who will help them. We believe that aggressive surgical treatment offers much to many of these patients.

Nasolabial flap in intraoral reconstruction. Review of 55 cases.

The nasolabial skin flap has proved very useful in reconstruction of anterior intraoral defects after ablation for cancer. The technique allows immediate single-stage reconstruction with local tissue. Minimal functional or cosmetic deformity results at the donor site. Fifty-five consecutive patients who underwent anterior intraoral reconstruction with 68 nasolabial flaps were followed up for 1 to 10 years. Only two flaps were total failures. Three flaps had partial tissue loss. Successful reconstruction without complication was obtained with 93 percent of the flaps. Technical refinements and considerations in flap design are presented.

Head and neck surgery in the aged.

This study was carried out to determine the perioperative mortality rate of patients over the age of 65 years who are undergoing major head and neck resections under general anesthesia. The total number of patients was 810 and the perioperative mortality rate (death within 30 days of operation) was 3.5 percent (29 of 810). This rate is relatively low when compared with the rate for patients undergoing similar procedures during the same period in the 35 to 65 years age group. Since 1975 reports of other types of surgery in the elderly have given perioperative mortality rates of from 4.8 to 26 percent. Previous studies of head and neck surgery in the elderly have given perioperative mortality rates of from 1.3 to 13.6 percent. Head and neck surgery in the elderly continues to be a safe procedure when compared with other types of surgery. As the portion of patients in the population over the age of 65 continues to increase, advanced age alone should not be a deterrent to performing aggressive surgical therapy for head and neck cancer.

Seroma prevention using fibrin glue during modified radical neck dissection in a rat model.

Seroma is a frequent sequelae of neck dissection involving cervical lymphadenectomy. The incidence is correlated with flap elevation, lymphovascular interruption, and tissue removal. Current methods of resolving seroma, such as vacuum drainage, are not risk free. A novel approach to this problem was the use of intraoperative topical fibrin glue. A model producing seromas was developed by modified radical neck dissection on Sprague-Dawley rats. Forty rats underwent this procedure. Twenty rats were treated with saline solution (control group) and 20 were treated with fibrin glue. At necropsy on day 5, a significant reduction in the frequency of seroma was noted in the fibrin glue group. Seventeen of 20 control rats had seroma whereas only 2 of 20 experimental animals had serous collection. The Fisher exact statistical correlation revealed p less than 0.000002; therefore, the use of fibrin glue in this role merits further evaluation.

Comparison of topical fibrin glue, fibrinogen, and thrombin in preventing seroma formation in a rat model.

Fibrin glue has been shown to decrease seroma formation in animal models. To further delineate this mechanism, the efficacy of fibrin glue was compared to topical fibrinogen and thrombin in preventing postoperative seromas. A model consistently producing seromas was developed by bilateral neck dissection, lymphadenectomy, and submandibular sialoadenectomy in the Sprague-Dawley rat. Groups of 20 rats underwent this procedure and were blindly treated with either fibrin glue, fibrinogen, thrombin, or saline control. Necropsy on postoperative day 5 revealed a statistically significant (chi-squared) decrease in seroma incidence using fibrin glue (0%) and fibrinogen (15%), while thrombin (95%) and saline (100%) were ineffective in preventing seromas. The use of fibrin glue and fibrinogen in this role merits further investigation.

Repair of a rodent nasal critical-size osseous defect with osteoblast augmented collagen gel.

OBJECTIVES/HYPOTHESIS: Facial skeletal defects are a common challenge for the otolaryngologist. Type I collagen gels have shown promise in the repair of nonhealing critical size defects (CSDs) of facial bone by providing scaffolding for new bone growth by osteoblasts at the defect perimeter. The objective of the present study was to evaluate the effect that suspending osteoblasts within a type I collagen gel has on the repair of a rodent facial CSD. STUDY DESIGN: Randomized controlled trial using a rodent model. METHODS: A previously described facial CSD was created by removing the nasalis bones with a cutting burr to the level of the nasal mucosal membranes on 18 Sprague-Dawley rats. Groups of six animals were treated with an implant containing either 300 microg of type I collagen gel, 12 x 10(5) osteoblasts suspended within type I collagen gel, or 12 x 10(5) fibroblasts suspended within type I collagen gel for comparison. After 30 days the animals-were examined at necropsy with planimetry, histological analysis of new bone growth, and radiodensitometric analysis of bone thickness. RESULTS: All animals had complete coverage with a thin layer of bone. Histological sectioning revealed an increased thickness in the osteoblast augmented group. Radiodensitometric measurements revealed a statistically significant increase in bone repair in the osteoblast group compared with the collagen-only group (P < or = .0005) and the fibroblast group (P < or = .04). CONCLUSION: Type I collagen gels augmented with an osteoblastic suspension significantly enhance the repair of nasal CSDs in a rodent model. The use of cultured bone precursor cells represents a leap forward in osteoengineering.

Nasal reconstruction using an osteoconductive collagen gel matrix.

BACKGROUND: Congenital malformations, granulomatous diseases, and trauma can all cause destruction of the nasal structural framework, resulting in functional nasal obstruction and altered facial cosmesis. Current methods of nasal reconstruction include cartilaginous and bony grafts, Silastic implants, and homograft only materials. However, these techniques have significant functional and cosmetic drawbacks and are not risk free. Native, isotonic, neutral-pH, space-filling type I collagen gels have been shown to mediate total repair of critical-size collagen grafts provide a framework for rapid intramembranous ossification and osteoconduction of bone from the perimeter of a defect, resulting in total bony coverage. OBJECTIVE: To evaluate a novel approach to nasal reconstruction using a major defect of the bony nasal dorsum with a type I collagen gel matrix. DESIGN: Sixteen retired male breeder Sprague-Dawley rats were divided into control and experimental groups. The nasal bones were exposed through a dorsal incision and completely removed with a bone-cutting drill to the level of the mucosal membranes of the nasal vestibule. Defects in the experimental animals were then implanted with 200 micrograms of type I collagen gel, with control animals receiving no inlay. After 6 weeks, the animals were examined with three-dimensional computed tomography before necropsy, at which time the defects were photographed, measured by planimetry, and sectioned for histologic analysis. RESULTS: Experimental defects were observed to manifest 100% surface area healing with a thin layer of bone using a type I collagen gel osteoconductive implant for nasal reconstruction. Conversely, control animals showed only a 5.7% (+/- 3.7% SD) healing by area. Histologic sections of the collagen gel implant revealed restoration of the anatomy with a thin plate of immature bone spanning the defect in continuity with the cartilage of the nasal septum and with apparent preservation of maxillonasalis suture lines. CONCLUSIONS: Native, isotonic, neutral-pH, space-filling collagen gels positively influenced the repair of large nasal defects, which showed minimal bone closure in untreated animals. Their use in this role merits further investigation.

Verapamil enhances the survival of primary ischemic venous obstructed rodent skin flaps.

The effect of verapamil, a calcium channel blocker, on the survival of skin flaps subjected to primary venous obstruction was studied. Skin flaps 9 x 4 cm, which are axial patterns with random extension, were elevated in Sprague-Dawley rats. A microvascular clamp was placed on the vein alone for 8 hours. Group 1 received verapamil (0.3 mg/kg) before flap elevation and before clamp release; group 2 received saline on the same schedule. Group 3 received verapamil (0.3 mg/kg) as above, plus every 8 hours for 5 days postoperatively. Group 4 received saline on the same schedule. There was no difference in survival between groups 1 and 2. Group 3 had 100% improvement in the flap survival compared with group 4 (78% vs 37%). Verapamil, if administered for the duration of the experiment, significantly increased flap survival.