Melanoma of the ear: results of a cartilage-sparing approach to resection.

Melanoma of the ear is often treated by composite resection of the skin and cartilage and, occasionally, by total auriculectomy. This review analyzes the oncologic, functional, and esthetic results of cartilage-sparing wide local excision for melanoma of the ear. This retrospective study reviewed patients with ear melanoma treated between 1997 and 2002. All patients were treated with cartilage-sparing wide local excision, and ears were reconstructed with skin grafts and/or local flaps. The majority of patients were men (16/18 patients) who ranged in age from 42 to 82 years. The most common sites of occurrence were the helical rim (7/18 patients) and the earlobe (6/18 patients). The average depth of invasion was 2.02 mm (range 0.4-6.0 mm). Sentinel lymph node biopsy was performed in 13 cases, of which only one was positive. The local control rate was 100 %, overall survival was 72 % (13/18 patients), and disease-specific survival was 89 % (16/18 patients). Average follow-up was 30.5 months (range 1-61). The rates for local control, overall survival, and disease-specific survival were excellent. These data indicate that for the majority of ear melanomas, cartilage-sparing wide local excision is an acceptable means of treatment.

The role of lymphatic mapping and sentinel lymph node biopsy in the staging and treatment of melanoma.

The incidence of malignant melanoma is increasing at an alarming rate, doubling in women and growing by more 300% in men during the past 25 years. The importance of diagnosing nodal metastatic disease, with the ability to detect smaller and smaller volumes of tumor in the sentinel lymph nodes (SLNs) biopsied using immunohistochemical staining, has impacted the accurate staging and stratification of melanoma patients. The role that elective lymph node dissection now plays in staging the melanoma patient and determining subsequent treatment has been greatly diminished in favor of less morbid and less invasive techniques that have a higher degree of accuracy in detecting occult nodal disease. This article explores what has driven the advent of selective or SLN biopsy, the rationale behind obtaining a preoperative lymphoscintigram, the technical details of the SLN biopsy procedure, and the refinement in the pathologic detection of ever smaller volumes of tumor in nymph node tissue removed. The role that these new modalities have played in changing the dynamic field of melanoma care is emphasized.

Electrically stimulated rectus abdominis muscle flap to achieve enterostomal continence: development of a functional canine model.

BACKGROUND: Dynamic myoplasty has many clinical applications and has proven to be a versatile surgical procedure with great promise. This procedure has been used to achieve fecal/urinary continence, as in the dynamic graciloplasty, and to augment cardiac ventricular function, as is commonly seen with dynamic latissimus cardiomyoplasty. In the present study, the authors describe a functional innovative island flap sphincter created from the rectus abdominis muscle in a large-animal model to provide stomal continence for future clinical studies. METHODS: The caudal region of the rectus abdominis muscle in eight mongrel canines (23 to 25 kg) was investigated through anatomical dissections during which the location of the neurovascular pedicles and the intersegmental muscle dimensions between the muscle inscriptions were noted. The rectus abdominis muscle was used to create functional dynamic stomal sphincters that were trained with subcutaneously implanted pulse stimulators. RESULTS: The neurovascular pedicles were consistently found in similar locations along the posterior medial aspect of the caudal portion of the canine's rectus abdominis muscle. The vertical height of the deep inferior epigastric pedicle and caudal intercostal nerve muscular mean entry points were 6.75 +/- 1.89 cm and 7.44 +/- 0.86 cm, respectively. The mean caudal intersegmental muscle length of the rectus abdominis muscle used to create the sphincter was 9.69 +/- 1.81 cm. CONCLUSIONS: The canine rectus abdominis muscle has reliable anatomical locations where the neurovascular pedicle may be found. This canine muscle may be used to create a continent island flap stomal sphincter. This large-animal sphincter model is versatile, durable, and easy to manipulate, with minimal morbidity to the animal.

Lymphadenectomy prior to rat hind limb allotransplantation prevents graft-versus-host disease in chimeric hosts.

In previous rat studies, the use of mixed allogeneic chimerism (MAC) to induce host tolerance to hind limb allografts has resulted in severe graft-versus-host disease (GVHD). The purpose of this study was to determine if immunocompetent cells in bone marrow (BM) and/or lymph nodes (LNs) of transplanted limbs were responsible for inducing GVHD in mixed chimeric hosts. [ACI-->Wistar Furth] chimeric rats received ACI hind limbs that were non-irradiated, irradiated (1050 cGy) or lymphadenectomized. Rejection, GVHD and donor chimerism was assessed. Chimeric hosts rejected none of their limbs. However, hosts of non-irradiated hind limbs succumbed to GVHD 22.4+/-0.8 days after transplantation. In contrast, chimeras that received irradiated or lymphadenectomized ACI hind limbs showed no clinical or histological signs of GVHD at 5 months. We conclude that mixed chimeric hosts are susceptible to GVHD due to the immunocompetent cell load provided by the LNs, not the BM, of hind limb allografts.

The acute and delayed effects of hydrostatic dilation on rat femoral arteries.

The technique of intraoperative vessel dilation is sometimes used to facilitate microvascular anastomosis and prevent vasospasm. Although this technique is not new, its application has not gained widespread acceptance mainly due to concerns raised about potential damage to the vessels acutely and during the postoperative period, leading to decreased vessel patency. The goal of this study was to determine the acute and delayed histologic effects of hydrostatic dilation on rat femoral arteries and to compare the response of dilated arteries to vasodilating and vasoconstricting agents. The femoral arteries in 22 rats were used in 2 experimental groups; 9 in the acute group and 13 in the delayed group. Six animals served as controls. After the vessels were exposed, a microcatheter was inserted into a segment of the vessel that had been isolated between 2 vessel clamps. Saline was infused into the artery until a pressure of 300 mm Hg was attained and then maintained for 60 seconds. In the acute group, the animals were euthanized at the end of the dilation, while in the delayed group the animals were euthanized 24 hours later. Hydrostatic dilation of rat femoral arteries was found to increased vessel diameter acutely, with subsequent relief and prevention of vasospasm during the ensuing 24 hours. Histologically, there was no increased damage of the vessel walls in the dilated vessels compared with control vessels. Based on the data reported in this study, hydrostatic dilation of rat microvessels appears to be safe and may be used to technically facilitate microanastomoses and decrease vasospasm.

Incidence of nonlocalization of sentinel lymph nodes using preoperative lymphoscintigraphy in 74 consecutive head and neck melanoma and Merkel cell carcinoma patients.

INTRODUCTION: Lymphatic drainage pathways in the head and neck region are more variable than in any other location of the body. Occasionally, head and neck lymphoscintograms fail to identify a definitive lymphatic drainage pattern, making preoperative and intraoperative identification of sentinel nodes very difficult. The purpose of this study was to determine the incidence of nonlocalization on lymphoscintigraphy of sentinel nodes in patients with head and neck cutaneous malignancies. METHODS: A retrospective chart review was conducted of a single surgeon's (WKS) 135 consecutive head and neck melanoma and Merkel cell cancer patients from August 1997 to August 2002. In all cases. technetium-99m sulfur colloid was the radioactive tracer used by the nuclear medicine department to perform the lymphoscintograms. RESULTS: Of the 135 patients, 74 underwent preoperative lymphoscintigraphy in preparation for performing a sentinel lymph node biopsy. Of these 74 patients, 5 (6.8%) were found to have nonlocalization of a sentinel node(s). Of the 5 patients who failed to localize, 3 had primary lesions near the midline scalp, while 2 had primary lesions located on the cheek. Two of the 5 patients underwent reinjection of the radioisotope by the treating surgeon (WKS) but failed to further localize the radiotracer. All 5 patients went on to have wide local excision of the primary cancer on the day of the lymphoscintogram, as well as undergoing intraoperative examination of all head and neck nodal basins with a handheld gamma detector. No focal areas of radiation were identified and no lymph nodes were biopsied. To date, 1 patient has developed distant metastases and has succumbed to her disease. The remaining 4 patients are free of disease. CONCLUSION: In a series of 135 consecutive patients with head and neck cutaneous malignancies, 74 of whom were treated with preoperative lymphoscintograms, a nonlocalization rate of 6.8% was found. This is a significant rate of nonlocalization and reflects either the inherent difficulty in imaging the head and neck region and/or the possible rapid rate of dye washout via multiple lymphatic drainage pathways that exist in this location.

Sentinel lymph node biopsy for head and neck melanomas.

BACKGROUND: Sentinel lymph node (SLN) biopsy for head and neck (H&N) melanomas may be more technically challenging compared with other locations because of complex lymphatic drainage patterns. This analysis was performed to compare the results of SLN biopsy for H&N, truncal, and extremity melanomas. METHODS: The Sunbelt Melanoma Trial includes patients aged 18 to 70 with melanomas > or = 1.0 mm thick. Statistical comparison was performed by chi2 or analysis of variance test. RESULTS: A total of 2610 patients were evaluated with a median follow-up of 18 months. The mean number of SLN per nodal basin was 2.8, 2.7, and 2.1 for H&N, truncal, and extremity melanomas, respectively. Median Clark level, Breslow thickness, and percentage of ulceration were similar between the groups. Peri-parotid SLN was identified in 25% of cases; there were no facial nerve injuries. SLN biopsy for H&N melanoma had higher false-negative rates at 1.5% (vs. 0.5% for trunk or extremity) but less histologically positive SLN at 15% (vs. 23.4%, and 19.5%; P <.001) compared with truncal and extremity melanoma. Blue dye was visualized less frequently in SLN of H&N melanoma patients compared with those with trunk or extremity melanomas. CONCLUSIONS: Preoperative lymphoscintigraphy and meticulous intraoperative search for blue/radioactive nodes may improve results in H&N melanomas.

Analysis of fiber type transformation and histology in chronic electrically stimulated canine rectus abdominis muscle island-flap stomal sphincters.

Dynamic skeletal muscle flaps are designed to perform a specific functional task through contraction and relaxation of their muscle fibers. The most commonly used dynamic skeletal flaps today are for cardiomyoplasty and anal or urinary myoplasty. Low-frequency chronic stimulation of these flaps enables them to use their intrinsic energy stores in a more efficient manner through aerobic metabolic pathways for increased endurance and improved work capacity. The purpose of this study was to (1) determine whether fiber type transformation from fatigue-prone (type II) muscle fibers to fatigue-resistant (type I) muscle fibers could be demonstrated in the authors' chronic canine stomal sphincter model where the rectus abdominis muscle was used to create a functional stomal sphincter, (2) assess whether there is any correlation between the degree of muscle fiber type transformation and the continence times, and (3) examine the long-term effects of the training regimens on the skeletal muscle fibers through histologic and volumetric analysis. Eight dynamic island-flap sphincters were created from a part of the rectus abdominis muscle in mongrel dogs by preserving the deep inferior epigastric vascular pedicle and the most caudal investing intercostal nerve. The muscular sphincters were wrapped around a blind loop of distal ileum and trained with pacing electrodes. Two different training protocols were used. In group A (n = 4), a preexisting anal dynamic graciloplasty training protocol was used. A revised protocol was used in group B (n = 4). Muscle biopsy specimens were obtained before and after training from the rectus abdominis muscle sphincter. Fiber type transformation was assessed using a monoclonal antibody directed against the fatigue-prone type II fibers. Pretraining and posttraining skeletal muscle specimens were examined histologically. A significant fiber type conversion was achieved in both group A and group B animals, with each group achieving greater than 50 percent conversion from fatigue-prone (type II) muscle fibers to fatigue-resistant (type I) muscle fibers. The continence time was different for both groups. Biopsy specimens 1 cm from the electrodes revealed that fiber type transformation was uniform throughout this region of the sphincters. Skeletal muscle fibers within both groups demonstrated a reduction in their fiber diameter and volume. Fiber type transformation is possible in this unique canine island-flap rectus abdominis sphincter model. The relative design of the flap with preservation of the skeletal muscle resting length and neuronal and vascular supply are important characteristics when designing a functional dynamic flap for stomal continence.

Preconditioning of latissimus dorsi muscle flaps with monophosphoryl lipid a.

The use of dynamic myoplasty to restore function to failing organs is an exciting new application of skeletal muscle flaps. A complication of large flap elevation that can compromise flap function is ischemia-induced necrosis; one approach to minimizing this is to pretreat tissues with ischemic preconditioning. The purpose of this study was to determine whether systemic administration of monophosphoryl lipid A, a drug known to mimic late-phase ischemic preconditioning in the heart, could reduce ischemia-induced necrosis in latissimus dorsi muscle flaps. Forty latissimus dorsi muscle flaps from 20 Sprague-Dawley rats were allocated into four groups. In group I (n = 10), flaps were not preconditioned and served as controls. In group II (n = 10), flaps received ischemic preconditioning with two 30-minute periods of ischemia interspersed by 10 minutes of reperfusion. In group III (n = 10), rats received an intravenous bolus of approximately 0.3 ml of monophosphoryl lipid A vehicle only. In group IV (n = 10), rats received an intravenous bolus of 450 microg/kg of monophosphoryl lipid A and vehicle. Twenty-four hours after treatment, all latissimus dorsi muscle flaps were elevated on a single neurovascular pedicle and subjected to 4 hours of ischemia. After 72 hours of reperfusion, latissimus dorsi muscles were harvested, weighed, stained with nitroblue tetrazolium, and assessed for percent necrosis using digitized images of muscle sections and computerized planimetry. The percent necrosis in ischemic preconditioning-treated flaps (group II) was significantly reduced by 57 percent (p < 0.05) compared with control flaps (group I). The percent necrosis in flaps treated with monophosphoryl lipid A (group IV) was significantly reduced by 58 percent (p < 0.05) compared with vehicle-control flaps (group III). There was no difference in mean percent necrosis between ischemic preconditioning (group II) and monophosphoryl lipid A-treated (group IV) flaps or between ischemic preconditioning-control (group I) and monophosphoryl lipid A vehicle-control (group III) flaps. Intravenous administration of systemic monophosphoryl lipid A mimics the late-phase protective effect of ischemic preconditioning in the authors' rat latissimus dorsi muscle flap model.

Successful treatment of 19 consecutive groin lymphoceles with the assistance of intraoperative lymphatic mapping.

Postoperative groin lymphoceles that fail to resolve spontaneously or with interventional therapy present a formidable problem that is associated with a high degree of morbidity. Numerous interventional methods and operative techniques have been described to treat these fluid collections, yet recurrence rates remain high. The use of lymphatic mapping has gained widespread use in the treatment of cutaneous malignancies and breast cancer and has been proven effective in delineating the course of lymphatic channels. We present here a series of 17 consecutive patients with 19 problematic groin lymphoceles who were treated with the assistance of intraoperative lymphatic mapping using isosulfan blue dye. To date there have been no recurrences and minimal morbidity associated with the technique and prescribed postoperative treatment regimen.

Intraoperative lymphatic mapping to treat groin lymphorrhea complicating an elective medial thigh lift.

Groin lymphoceles and lymphorrhea are a rare complication of medial thigh lift procedures. The author describes a case in which a very thin patient developed groin lymphorrhea after an uncomplicated medial thigh lift procedure. Initial treatment interventions, including edema control and the placement of a drain with surgical exploration, failed to control the lymphatic leak. Additionally, the onset of an infection and abscess formation complicated the treatment efforts. Using techniques well established in treating cutaneous malignancies, the lymphocele was treated successfully by identifying three separately damaged lymphatic channels with the use of intraoperative lymphatic mapping with blue dye. No drains were needed and the immediate cessation of lymph flow was noted. Using this novel adaptation of a well-known technique, the groin lymphocele was able to be repaired quickly and effectively with minimal morbidity and no evidence of recurrence to date.