Microvascular transplantation and replantation of the rabbit submandibular gland.

BACKGROUND: Xerostomia is a devastating complication of radiation therapy. Previous research has demonstrated that submandibular glands may be removed from the neck and transplanted using microvascular techniques, with good gland survival. However, microvascular transplantation and replantation has never been attempted on a composite tissue such as a salivary gland. OBJECTIVE: To evaluate the ability of a rabbit submandibular gland to undergo 2 successive microvascular transplantations. SUBJECTS AND DESIGN: Study rabbits underwent a midline neck incision with dissection of a submandibular gland to its arterial and venous pedicle. Microvascular techniques were then used to transplant the gland to the femoral system of the right groin. The incisions were reopened later under surgical conditions. The transferred gland was examined for survival and patency of its artery and vein. Healthy glands were dissected and transferred to a suitable artery and vein within the neck, where they were again reanastamosed using microvascular surgical techniques. After additional time, the gland was again examined for survival and pedicle patency, then removed and evaluated for histopathological evidence of survival. RESULTS: Surgical technique evolved during the course of this work to avoid encountered pitfalls. After refining the technique, we have determined that the rabbit submandibular gland is able to withstand successive microvascular transplantation and replantation with good likelihood of long-term survival, according to histopathological criteria. CONCLUSIONS: The rabbit submandibular gland is able to undergo microvascular transplantation and replantation with evidence of long-term survivability and preserved function. The body's natural response to surgery and tissue transplantation makes replantation a technical challenge; however, methods delineated herein alleviate many of the potential pitfalls. Extending these results to humans, patients who are to undergo radiation therapy could have a disease-free gland removed from the neck, transferred outside of the field of radiation, and then returned to the neck at the completion of radiation therapy. This may enable them to maintain salivary gland function and maintain oral cavity function and comfort.

Hair-bearing temporoparietal fascial flap reconstruction of upper lip and scalp defects.

BACKGROUND: The temporoparietal fascial flap has proven to be a versatile flap for a broad spectrum of reconstructive problems in the head and neck. The temporoparietal fascial flap is a thin, pliable layer of richly vascularized tissue that may be transferred either pedicled or free and alone or as a carrier of subjacent bone or overlying skin and scalp. OBJECTIVE: To report our experience using a hair-bearing temporoparietal fascial flap for reconstruction in 6 male patients with extensive upper lip and scalp defects, including a discussion of the surgical anatomy and technique. METHODS: Temporoparietal fascial flaps with overlying scalp were used as pedicled and free flaps for the reconstruction of upper lip and scalp defects. RESULTS: All reconstructive results were satisfactory. Oral competence, measured by both speech and mastication performance, was achieved in patients with upper lip defects. Healthy scalp coverage was obtained in patients with local defects. The cosmetic appearance was satisfactory to all patients. CONCLUSIONS: Ideal reconstruction of large upper lip and scalp defects is achieved with local tissue that best mimics the normal face color, texture, and hair-bearing qualities. Hair-bearing temporoparietal fascial flaps possess these characteristics and are an excellent choice for the restoration of function and aesthetics.

A new artificial nerve graft containing rolled Schwann cell monolayers.

This study hypothesized that introducing high numbers of Schwann cells in monolayers via a novel rolled graft architecture would promote robust nerve regeneration. The objective was to place adherent Schwann cells in artificial nerve grafts and to assess regeneration through the Schwann cell-laden grafts compared with that through acellular grafts and autografts. Schwann cells were isolated from neonatal Fisher rats. Small intestinal submucosa (SIS) was harvested from adult Fisher rats, cut into 7 mm x 8 cm pieces, and pinned out. Schwann cells were plated onto the strips, allowed to reach confluence, and subsequently rolled into a laminar structure and implanted across a 7-mm gap in the rat sciatic nerve (n = 12). Control animals received SIS conduits without Schwann cells (n = 11) or autograft repair (n = 12). At 10.5 weeks, functional regeneration through the Schwann cell-laden grafts, measured by both sciatic function index and extensor postural thrust testing, exceeded that through the cell-free grafts and approached that achieved through autografts. These results highlight the role of Schwann cells in nerve regeneration. Regenerative results approaching autograft levels in the Schwann cell-laden group suggest that this methodology may ultimately be useful in clinical nerve repair.

Temporoparietal fascial flap in orbital reconstruction.

OBJECTIVE: To evaluate the success of the temporoparietal fascial flap (TPFF) in the primary or secondary reconstruction of difficult orbital defects and to review the surgical techniques. DESIGN: Retrospective analysis. SETTING: Tertiary medical center. PATIENTS: Nine patients with diverse orbital cavity or periorbital soft tissue and bony defects due to trauma, benign or malignant neoplasms, and radiation treatment. INTERVENTIONS: Temporoparietal fascial flap anatomy and techniques of harvest and inset are reviewed in detail. Four cases are presented to illustrate possible variables in orbital reconstruction. Variables examined include the location of defects, the success of flap survival in orbital cavities after primary or secondary reconstruction, the effects of prior irradiation on flap survival, and the possibility of concurrent osteointegrated implant placement with TPFF reconstruction. MAIN OUTCOME MEASURES: Functional and aesthetic outcomes were determined by physical examination and preoperative and postoperative photographs. RESULTS: All patients had successful transfer of TPFF grafts without flap compromise. Temporoparietal fascial flap was a viable option for subtle orbital and malar contour defects. In chronically inflamed wounds such as with osteoradionecrosis and orbitoantral fistula, TPFF successfully restored vascularity, obliterated the defects, and enabled the placement of osteointegrated implants. The TPFF also supported the concurrent placement of a free calvarial bone graft. Finally, split-thickness skin grafted onto a pedicled TPFF showed 100% survival. CONCLUSIONS: The TPFF is one of the most reliable and versatile regional flaps in the head and neck for orbital reconstruction. This study presents the use of TPFF in a variety of orbital defects, from lateral bony rim defects to total exenteration. Timing of repair in this study spans from immediate reconstruction to reconstruction delayed more than 50 years after the initial injury. In all cases, reconstruction with TPFF resulted in improved bony and soft tissue contours, and incurred minimal morbidity.

Use of the radial forearm fasciocutaneous free flap and montgomery salivary bypass tube for pharyngoesophageal reconstruction.

BACKGROUND: Head and neck reconstructive surgeons involved in pharyngoesophageal reconstruction have several options available to repair the defect after partial or total laryngopharyngectomy. There is no uniform agreement among head and neck surgeons as to which of the most frequently used techniques offers the best results. METHODS: A retrospective study was performed on 20 consecutive patients who had undergone reconstruction of the hypopharynx and cervical esophagus using a radial forearm free flap with Montgomery salivary bypass tube at the Massachusetts Eye and Ear Infirmary in Boston, Massachusetts, and St. Louis University, Department of Otolaryngology-Head and Neck Surgery between 1992 and 1996. This reconstruction was used for primary reconstruction after total or partial laryngopharyngectomy with cervical esophagectomy, partial pharyngectomy sparing the larynx, and for reconstruction of the stenotic neopharynx after laryngectomy. RESULTS: The overall rate of pharyngocutaneous fistula was 20%, and the rate of postoperative stricture was 10%. Of patients reconstructed with this technique, 85% were able to resume oral alimentation, whereas 15% remained G-tube dependent. Of the 18 patients who did not have their larynges remain intact, 6 were able to develop useful tracheoesophageal speech. CONCLUSIONS: The results of this study show that the radial forearm fasciocutaneous free flap in combination with the Montgomery salivary bypass tube is extremely useful for reconstruction of partial and circumferential defects of the hypopharynx and cervical esophagus.

Induction of facial muscle neurotization by temporalis muscle transposition: literature review and animal model evaluation using horseradish peroxidase uptake.

OBJECTIVE: To study the concept of facial muscle reinnervation from the trigeminal pathway following facial nerve paralysis. DESIGN AND METHODS: We studied this phenomenon in an animal model using the neuronal marker, horseradish peroxidase (HRP). The temporalis transposition procedure was performed at varying intervals post facial nerve transection. To evaluate the trigeminal-facial reinnervation process and its timing, the zygomaticus major muscle was injected with HRP at varied periods after temporalis transposition, and histologic sections of the brainstem nuclei were examined for the final location of the HRP. RESULTS: The presence of HRP in the trigeminal nucleus provided evidence of trigeminal-facial neurotization in those animals that underwent temporalis transposition up to 2 months following facial denervation and in which the HRP injection was performed 4 months after temporalis transposition. CONCLUSIONS: The findings of our pilot study are strongly supportive of the trigeminal-facial neurotization hypothesis in those animals that underwent temporalis transposition up to 2 months post facial denervation and in which 4 months were allowed thereafter for adequate neurite ingrowth and neurotization to occur. This suggests that the neurotrophic signals are greatest up to 2 months post denervation and denotes the optimal time for performance of reconstructive procedures. Future studies with a larger number of animals in each group will be necessary to ensure more potent statistical significance and to augment our experimental evidence that trigeminal-facial crossover does occur and can be used as an adjunctive concept to maximize early rehabilitation of the paralyzed face.

A comparison of assessments of functional recovery in the rat.

Assessment of functional recovery following any peripheral nerve manipulation is critical. While quantitative neurobehavioral testing has been developed in the anesthesia literature for the assessment of neural function, the surgical literature relies mainly on walking track analysis for evaluation of motor recovery. The latter method is both cumbersome to perform and difficult to quantify. We compared standard walking track analysis with the quantitative neurobehavioral tests recently developed for anesthetic testing. We found a close correlation between the recovery predicted by walking track analysis and that suggested by neurobehavioral testing. In addition, the neurobehavioral test battery offered information regarding the rate of return of pure motor function, complex integrated function, proprioceptive function, and sensation. The tests are easier to perform and less susceptible to interpretative error. Neurobehavioral testing may be an effective substitute for walking track analysis in the assessment of functional recovery following manipulation of the rat sciatic nerve.

Combining free flap reconstruction and craniofacial prosthetic technique for orbit, scalp, and temporal defects.

OBJECTIVES: To identify factors leading to successful application of prosthetic techniques following free flap reconstruction of the orbit, scalp, and temporal region. STUDY DESIGN: Retrospective review. METHODS: Twenty-eight patients who underwent free flap reconstruction for defects of these regions between 1989 and 1996 were reviewed for clinical parameters, flap loss, patient survival, and implant loss rate. Prosthetic usage rates were compared before and after introduction of a site-specific reconstructive algorithm. RESULTS: Free flap success rate was 93%, whereas osseointegrated implant loss rate was 11%. In addition to implants, a reconstructive strategy that provided thin, vascular tissue between bone and skin, a flat platform in the temporal region, and preservation of orbital cavity depth led to increased prosthetic usage. CONCLUSIONS: Craniofacial prosthetic techniques can significantly augment the results of free flap surgery for the orbit, scalp, and temporal region. Successful combination of these techniques requires a site-specific surgical approach.

Update on facial nerve repair.

Facial paralysis is a complex clinical problem, and optimal management strategies continue to evolve. Areas of active investigation include improvements in neural repair techniques, and the examination of new anastomotic materials and methods, as well as the development of alternative neural bridging materials. Current controversies in nerve grafting techniques, the use of novel neural conduit materials, timing of facial nerve procedures, and frontiers in experimental nerve grafting techniques are reviewed.

Tissue engineering in facial plastic and reconstructive surgery.

Current biomaterials technology meets some of the needs of the facial plastic and reconstructive surgeon. However, there is a genuine need for improvement in the area of tissue replacement. The principle of tissue engineering provides a natural way to generate needed tissue using the patient's own cells as building blocks, coupled with biodegradable polymers which have been used safely in [figure: see text] patients for decades. This technology enables the creation of complex structures which ultimately have no immunogenicity. Current obstacles to human clinical trials for auricular repair are being pursued for resolution, and the number of new tissues which it may be possible to generate in this fashion continues to expand. Through continued experimentation and collaboration among surgeons, chemical engineers, and materials scientists, we are certain that the barriers to widespread clinical use for this emerging technology will be overcome.

Endoscopic facial surgery.

The emergence of endoscopically assisted cosmetic surgery has been very rapid. Public demand has burgeoned this trend resulting in the widespread use of these techniques prior to their proven efficacy. Fortunately, the results to date are favorable. The endoscopic brow and forehead lift appear to be as reliable as the open coronal approach while inflicting less incisional morbidity and decreased postoperative recovery time. This combination of decreased morbidity and post surgical discomfort have led to increased patient acceptance of browlifting. The soft-tissue orbital complex is composed of the eyebrow, upper and lower eyelids, and the malar prominence. When used in conjunction with blepharoplasties, the endoscopic browlift and midfacial suspension dramatically improve the appearance of the eye when compared to blepharoplasty alone. The applied surgical anatomy, indications, and operative technique used in endoscopic upper facial rejuvenation are detailed. Surgeons who are not utilizing the endoscopic techniques are encouraged to do so when repositioning the eyebrow and malar prominence would improve the aesthetic result.

Trigeminal neo-neurotization of the paralyzed face.

Sporadic reports throughout the literature have documented the spontaneous return of facial function following deliberate intraoperative sacrifice of the facial nerve. Trigeminal reinnervation of the facial muscles has been suggested as one possible mechanism for this occurrence. Evidence for the phenomenon of trigeminal neo-neurotization has been documented experimentally. The case of a 62-year-old woman who underwent total left parotidectomy with transection of a large facial nerve segment is presented in order to provide further clinical evidence supporting trigeminal neo-neurotization of the facial nerve. Despite the lack of any efforts to reinnervate the patient or graft the facial nerve defect, the patient spontaneously developed return of facial function. Postoperative clinical and electrical testing in this case supports trigeminal-facial reinnervation as the cause for return of facial function. The case report is summarized with a brief discussion, and the relevant literature is thoroughly reviewed.

Fixed mandibular implant after microvascular mandibular reconstruction.

OBJECTIVE: To evaluate the use of fixed mandibular implants to retain dental prostheses after microvascular mandibular reconstruction. DESIGN: Case series. SETTING: Tertiary referral center. PATIENTS: Eight patients with microvascular mandibular reconstruction after mandibular resection. OUTCOME MEASURES: Clinically noted functional results, serial radiographic evidence of fixed mandibular implant and mandibular integrity, and complications encountered. RESULTS: Eight of 8 fixed mandibular implants were successfully placed and remained stable. The follow-up period ranged from 10 to 21 months (mean, 14.3 months). CONCLUSION: The use of fixed mandibular implants to retain dental prostheses after microvascular mandibular reconstruction is a safe and effective treatment option.

Transfacial transclival approach for midline posterior circulation aneurysms.

OBJECTIVE: To evaluate the use of an anterior, transfacial transclival approach to midline posterior circulation aneurysms in five patients. SURGICAL APPROACH: A skin incision is made on the right side of the nose with subsequent bony and cartilaginous disarticulation of the nasal complex. The nose remains attached along the left side and is reflected laterally. Removal of the nasal septum and bilateral ethmoidectomy, medial maxillectomy (usually bilateral), and opening of the sphenoid yield a large triangular exposure of the anterior clivus. After removal of the clivus with a drill, the vertebral and basilar arteries are exposed through a midline dural opening. RESULTS: The approach provided excellent exposure of basilar artery trunk aneurysms with room available for temporary clip placement in three patients. In a fourth patient, a midline posterior inferior cerebellar artery aneurysm was clipped using this technique. A basilar trunk dissection was treated by proximal basilar occlusion through this exposure in a fifth patient. Although three patients developed transient cerebrospinal fluid leaks with symptoms of meningitis, no permanent neurological morbidity resulted from the use of the approach. CONCLUSION: The transfacial transclival approach to midline aneurysms of the basilar trunk and its branches provided excellent exposure for surgical treatment in five patients. No patient had postoperative palatal dysfunction and cosmetic results were excellent. Cerebrospinal fluid leak and meningitis continue to be the major drawbacks to the use of this approach, although the availability of modern broad-spectrum antibiotics lessens the chance of permanent neurological sequelae.

Assessment of functional morbidity in the radial forearm free flap donor site.

OBJECTIVE: To quantitate the functional morbidity to the hand and wrist due to the harvest of a radial forearm free fasciocutaneous flap. DESIGN: Case-control study with age-matched control groups. SETTING: Tertiary care hospital. PATIENTS: A consecutive sample of 21 patients who underwent a radial forearm free flap reconstruction of the head and neck from June 1993 to February 1995 constitute the experimental group. Thirteen of those eligible patients participated in the study. Two control groups were identified. One cohort included 13 patients with head and neck cancer who underwent free tissue transfer other than the radial forearm flap. The other cohort consisted of 16 subjects who were healthy volunteers, patients without cancer, or patients who were considered to be cured of cancer. OUTCOME-MEASURES: Wrist range of motion, grip strength, and sensation in the radial, ulnar, and median nerve distributions on the hands, bilaterally. RESULTS: No significant differences (P > .05) were detected between the groups for the modalities that were tested. CONCLUSION: There is minimal functional morbidity associated with the harvest of the radial forearm free fasciocutaneous flap.

The importance of mandibular position in microvascular mandibular reconstruction.

The challenge of mandibular reconstruction rests in the difficulty of re-creating the intricate three-dimensional relationship of the oral cavity, thereby ensuring occlusal relationships, oral competence, and facial contour. Recent advances in microvascular surgery have made reliable transfer of autologous tissue possible, hut successful reconstruction depends on accurate insetting of the bone flap. The authors reviewed their five years of experience with mandibular reconstruction and found six patients with a poor reconstructive result secondary to improper insetting of the bone flap. Anteromedially rotated and free-floating proximal mandibular segments appeared to be the most significant contributor to incorrect placement of the bone flap. Based on their findings, the authors devised a simple technique for stabilizing proximal mandibular segments.