A non-spherical core in the explosion of supernova SN 2004dj.

An important and perhaps critical clue to the mechanism driving the explosion of massive stars as supernovae is provided by the accumulating evidence for asymmetry in the explosion. Indirect evidence comes from high pulsar velocities, associations of supernovae with long-soft gamma-ray bursts, and asymmetries in late-time emission-line profiles. Spectropolarimetry provides a direct probe of young supernova geometry, with higher polarization generally indicating a greater departure from spherical symmetry. Large polarizations have been measured for 'stripped-envelope' (that is, type Ic; ref. 7) supernovae, which confirms their non-spherical morphology; but the explosions of massive stars with intact hydrogen envelopes (type II-P supernovae) have shown only weak polarizations at the early times observed. Here we report multi-epoch spectropolarimetry of a classic type II-P supernova that reveals the abrupt appearance of significant polarization when the inner core is first exposed in the thinning ejecta (approximately 90 days after explosion). We infer a departure from spherical symmetry of at least 30 per cent for the inner ejecta. Combined with earlier results, this suggests that a strongly non-spherical explosion may be a generic feature of core-collapse supernovae of all types, where the asphericity in type II-P supernovae is cloaked at early times by the massive, opaque, hydrogen envelope.

Single-stage reconstruction of mandibular and soft tissue defects using a free osteocutaneous groin flap.

Microvascular reconstruction of the mandible and soft tissues using the composite groin flap is ideal in selected patients. No other available bone so closely approximates the mandible in both thickness and curvature as does the iliac crest. The soft tissues are available for reconstruction and may allow the surgeon to avoid a second flap, except in cases where both lining and cover are needed. The deep circumflex artery is of generous size, usually 2 to 2.5 mm in diameter, allowing greater reliability in the microvascular anastomoses. The flap has a fairly long vascular predicle, 6 to 8 cm. The ability of this flap to withstand irradiation and infection because of its blood supply permits early institution of postoperative radiotherapy and prevents bone loss due to small intraoral wound dehisicence or total flap loss. Although the donor site requires extensive dissection, it can be closed primarily, eliminating the need for skin grafts or other flaps. As further experience is gained with this flap, both the functional and cosmetic results should be improved. In patients undergoing resection of the remaining portion of the mandible, the symphysis or the anterior portion of the mandible, a procedure of this type should be done primarily to prevent deformity and to minimize disability for the patient.

Pectoralis major musculocutaneous flap: a new flap in head and neck reconstruction.

The pectoralis major musculocutaneous flap described by Ariyan has great potential in single stage reconstructions of the head and neck. The advantages of the flap are greater length, improved vascularity, bulk, and one-stage reconstruction of oropharyngeal defects. The flap was used successfully in eight patients to reconstruct large defects in the head and neck area. Experience to date indicates that this flap has greater versatility than the deltopectoral flap in one-stage head and neck reconstructions.

Cutaneous melanoma of the head and neck.

Melanoma of the head and neck, if diagnosed early and treated with aggressive appropriate surgical therapy, is potentially curable in up to 80 to 90 per cent of the cases. The use of microscopic staging by level of invasion and thickness of the tumor is helpful in determining the appropriate surgical procedure for the individual patient and is of prognostic significance. If possible, prophylactic incontinuity regional node dissection should be performed for melanomas of the head and neck that have invaded to Level III or deeper, especially those that are greater than 1.5 mm in thickness. The histological status of the regional nodes is beneficial both therapeutically and prognostically, in that patients who have negative nodes have a better prognosis than those with microscopically positive nodes. Also, these patients with microscopically positive nodes have a much better survival than those with macroscopically positive nodes. Melanoma of the head and neck should be treated very aggressively with wide excision of the primary tumor in order to prevent local recurrence and further spread of the disease. Since surgical treatment is the only effective curative measure for melanoma, all localized tumor in the region of the primary and solitary distant metastasis should be removed if possible. The adjunctive use of chemotherapy and immunotherapy when regional nodes are involved with melanoma is being studied and may be of some benefit. The combinations of surgical therapy, chemotherapy, immunotherapy, and radiotherapy offers the patient with advanced disease significant palliation, sometimes for prolonged periods. The treatment of head and neck melanoma is best summarized by the statement in the December 4, 1965 of The Lancet.-.29 "The surgeon who first operates on a malignant melanoma has a great responsibility. Prompt and competent action will give the patient a chance of survival better than in most other forms of cancer. The only additional operative surgical skill required is the ability to cut and apply split skin grafts. If he lacks confidence therein, let the surgeon refer the case at once and certainly before he has ruined, by niggling interference, the patient's chance of survival."

Effects of topical applications of epidermal growth factor on wound healing. Experimental study on rabbit ears.

In wounds in rabbit ears, the application every 12 hours of an ointment containing epidermal growth factor appears to produce faster and better healing. The resulting epithelium is thicker and more cellular than in the untreated ear wounds, and more fibroblasts appeared sooner during the healing process. Less wound contracture occurred in the EFG-treated wounds, and wound maturation occurred earlier. The healed wounds that had been treated with EGF more closely resembled the surrounding normal tissue, producing less local deformity than in the controls. It is too early to know whether this will have clinical application, but other experiments are under way to further investigate the effects of EGF on wound healing.

Resection of a massive arteriovenous malformation of the head and neck.

We report a patient with a massive arteriovenous malformation of the head and neck treated by surgical extirpation of the lesion. Arteriography, hypotensive hypothermic anesthesia, and the intraoperative use of the Doppler flowmeter were most helpful in this case.

Cutaneous melanoma: a twenty-year retrospective study with clinicopathologic correlation.

The survival of melanoma patients is directly related to the involvement of regional nodes and to the microscopic level of invasion of the tumor. During the past 10 years, with the increased use of aggressive surgical therapy (wide local excision or re-excision of the primary tumor and prophylactic dissection of predictably involved regional nodes) the 5-year survival rate has more than doubled. The 5-year survival has doubled in those patients with regional lymph node involvement who were infused for 5 days with L-phenylalanine mustard. Perfusion of the lower extremities with L-phenylalanine mustard has been abandoned at Vanderbilt. The potential aggressiveness of a specific melanoma can be predicted, and thus an appropriate treatment may be planned.

Fluorescein test for prediction of flap viability during breast reconstructions.

The fluorescein test is a useful ancillary procedure for predicting the viability of breast flaps in reconstructive procedures after subcutaneous mastectomy or radial mastectomy.

Fasciocutaneous island flap based on the medial plantar artery: clinical applications for leg, ankle, and forefoot.

Soft-tissue deficits over the plantar forefoot, plantar heel, tendo calcaneus, and lower leg are often impossible to cover with a simple skin graft. The previously developed medial plantar fasciocutaneous island flap has been adapted to cover soft-tissue defects over these areas. This fasciocutaneous flap based on the medial plantar neurovascular bundle is capable of providing sensate and structurally similar local tissue. Application of this fasciocutaneous island flap is demonstrated in 12 clinical cases. Successful soft-tissue cover was achieved on the plantar calcaneus (four patients), tendo calcaneus (four patients), lower leg (two patients), and plantar forefoot (two patients). Follow-up ranged from 6 months to 5 years. All flaps were viable at follow-up. Protective sensation was present in 11 of 12 flaps evaluated at 6 months. In addition, all 11 patients were able to ambulate in normal footwear. The medial plantar island flap seems to be more durable than a skin graft, and the donor site on the non-weight-bearing instep is well tolerated. This study demonstrates that the medial plantar fasciocutaneous island flap should be considered as another valuable tool in reconstructive efforts directed at the plantar forefoot, plantar heel, posterior ankle, and lower leg.

Effect of lymphangiography on lymphedema.

Lymphangiography, using oily radiopaque Lipiodol Ultra Fluid has been shown to increase lymphedema in one-third of the patients with obstructive lymphedema and to cause lymphatic obliteration (demonstrated histologically). No effective element has been observed, although subclinical infection could not be ruled out. Allergy is another possible contributor, but the evidence from this series suggests that Lipiodol may act as a direct irritant when it is not rapidly cleared, as in the case of obstructive lymphedema, and proceed to obliteration of the residual lymphatics. On the basis of these findings, elective routine preoperative lymphangiography for lymphedema is considered strongly inadvisable.

Immediate reconstruction of the pharynx and cervical esophagus with the pectoralis major myocutaneous flap following laryngopharyngectomy.

The "island" pectoralis major myocutaneous flap has been used in nine patients for immediate hypopharyngeal and cervicoesophageal reconstruction following laryngopharyngectomy. Two patients underwent total hypopharyngeal and cervicoesophageal reconstruction. Postoperative evaluation revealed adequate lumens with no evidence of stricture. There was retained innervation of the flaps through the lateral pectoral nerve, but no additional innervation from the cricopharyngeal musculature could be demonstrated. Normal esophageal motility was maintained, but cervicoesophageal pressures were diminished. Donor site morbidity was minimal, and the complication rate was low. We present the pectoralis major myocutaneous flap as an alternate method for hypopharyngeal and cervicoesophageal reconstruction.

Split jejunal free-tissue transfer in oropharyngoesophageal reconstruction.

From January 1, 1981 to July 1, 1981, ten patients underwent immediate reconstruction utilizing split jejunal free-tissue transfers following resection of large oropharyngeal neoplasms. All 10 flaps were successfully transferred. Three patients were irradiated preoperatively and six patients were irradiated 2 to 3 weeks postoperatively. Nine patients were available for follow-up until their death from 10 to 39 months postoperatively (average 26 months). All but two patients died of their original tumor. Six of the nine patients had a good early functional result; taking semisoft or soft diets allowed them to maintain or gain weight. Three patients had poor early results with limited oral feedings due to repeated aspiration in two and severe gastroesophageal reflux in another. Postoperative graft biopsies were obtained in five patients, showing normal mucosa or mild chronic inflammation histologically even following irradiation. Postoperative barium studies showed varying degrees of graft peristalsis. Complication rates were acceptable, and donor-site morbidity was minimal. Neither preoperative nor postoperative radiation affected the viability of the grafts. Therefore, this technique should continue to find application as a reliable method of providing like tissue for reconstructing a variety of large oropharyngeal defects.

Internal fixation of the sternum in median sternotomy dehiscence.

Sternal dehiscence may be defined as separation of the bony sternum and manubrium following median sternotomy. It may occur at any time postoperatively and has various etiologies. Restoration of sternal integrity in sternal dehiscence is a challenging problem, particularly when associated with deep-seated infection. This report reviews a single-stage technique that virtually eliminates the infected sternotomy wound and provides anatomic reduction and stabilization of the sternum. Complete debridement of infected and/or nonviable soft tissue, bone, and cartilage is followed by pulse irrigation. Parallel stainless steel mandibular reconstruction plates are then placed on each side of the remaining sternum and wired together. One or more transmanubrial compression plates may be added. Bilateral pectoralis major musculocutaneous flap advancement and primary skin closure is performed over two to three closed suction drains. From January of 1994 to July of 1996, this technique was used by the same surgeon in 26 male and 4 female patients aged 43 to 78 years (mean = 61). Indications for the operation were sternal dehiscence with infection (osteomyelitis and/or mediastinitis) in 14 patients and sternal dehiscence without infection in 16 patients. All patients survived to discharge with mean time on the ventilator, intensive care unit length of stay, and postoperative length of stay of 0.7, 2, and 8 days, respectively. Choice and duration of antibiotics were based on culture results and operative findings. Subsequent hardware removal was necessary in one patient for hardware loosening and three patients for late periplate infection. A closed wound was eventually achieved in all 30 patients, and sternal stability was restored in 29 patients. In the management of sternal dehiscence, the described technique of internal fixation can provide anatomic sternal reduction and stabilization, elimination of infection, and wound closure in a single-stage operation. Successful outcomes were achieved despite the presence of severe infection.

Use of the free dorsalis pedis flap in head and neck repairs.

Many defects of the head and neck can be readily repaired with a free dorsalis pedis flap, and we report success with these flaps in 9 of 12 cases. A precise knowledge of the anatomy of the arterial supply of the flap is necessary. Preoperative arteriography is recommended if the dorsalis pedis artery is not easily palpable, or if an anomalous distribution of the artery along the dorsum of the foot is sus pected. However, the transfer of the flap should be delayed for two weeks after preoperative arteriography is performed. The one-stage soft tissue reconstruction with a free dorsalis pedis flap has been associated with minimal morbidity and good acceptance by patients. A delay procedure for the flap seems to enhance the chances of complete survival which is so necessary in the repair of intraoral and pharyngeal defects. Careful attention to details and close monitoring of the flap will minimize morbidity. In case of an early failure of a flap, a secondary reconstruction by a different flap can be done in the first 48 to 72 hours. Early postoperative radiotherapy has been well tolerated over these free flaps.

Fibrinolytic activator activity in human neoplasms.

The results of this study suggest that many malignant tumors contain low levels of fibrinolytic activator activity. Evidence is presented to suggest that this low activity may be due to the presence of an inhibitor of fibrinolysis. The presence or absence of measurable fibrinolytic activator activity, and/or inhibitor in neoplastic growths may enable one to predict the probability of viable metastases to a distant site.

Pectoralis major musculocutaneous flaps: long-term follow-up of hypopharyngeal reconstruction.

We have reviewed our experience with 25 patients who have undergone major head and neck resections and required hypopharyngeal pectoralis major flap reconstruction. Six patients were alive 1 year following reconstruction and five patients consented to evaluation of flap function with endoscopy, with biopsy, barium swallow, and esophageal manometrics. The patients were older (61 +/- 6 years) and the flaps were large (42 +/- 9 cm2). Barium studies were the most useful method of evaluating these patients. Postoperative stricture and laryngeal aspiration were found in two patients. Biopsy of the flap demonstrated loss of keratin in the overlying epidermis, while the gross appearance was more like the surrounding mucosa. A review of dietary intake in these cases revealed that two patients weighed less than their preoperative weights, while another refused oral feedings despite a good functional result. Three of five patients preferred gastrostomy feedings to oral alimentation.

Lymphoscintigraphy as an adjunctive procedure in the perioperative assessment of patients undergoing microlymphaticovenous anastomoses.

Microlymphaticovenous anastomoses provide a potential for reducing lymphedema of the upper extremity complicating radical mastectomy or irradiation. Lymphoscintigraphy is a valuable investigative modality in the perioperative evaluation of patients undergoing this surgical procedure. The radionuclide studies provide information regarding structural change and physiologic derangement with a low radiation dose to the patient. It is a simple, painless procedure requiring minimal skill and no surgical intervention. In addition, a reproducible method for preparing a radiocolloid suitable for lymphatic imaging using an approved drug as a precursor has been developed.

Spatial-symbolic Query Engine in Anatomy.

OBJECTIVES: Currently, the primary means for answering anatomical questions such as 'what vital organs would potentially be impacted by a bullet wound to the abdomen?' is to look them up in textbooks or to browse online sources. In this work we describe a semantic web service and spatial query processor that permits a user to graphically pose such questions as joined queries over separately defined spatial and symbolic knowledge sources. METHODS: Spatial relations (e.g. anterior) were defined by two anatomy experts, and based on a 3-D volume of labeled images of the thorax, all the labeled anatomical structures were queried to retrieve the target structures for every query structure and every spatial relation. A web user interface and a web service were designed to relate existing symbolic information from the Foundational Model of Anatomy ontology (FMA) with spatial information provided by the spatial query processor, and to permit users to select anatomical structures and define queries. RESULTS: We evaluated the accuracy of results returned by the queries, and since there is no independent gold standard, we used two anatomy experts' opinions as the gold standard for comparison. We asked the same experts to define the gold standard and to define the spatial relations. The F-measure for the overall evaluation is 0.90 for rater 1 and 0.56 for rater 2. The percentage of observed agreement is 99% and Cohen's kappa coefficient reaches 0.51. The main source of disagreement relates to issues with the labels used in the dataset, and not with the tool itself. CONCLUSIONS: In its current state the system can be used as an end-user application but it is likely to be of most use as a framework for building end-user applications such as displaying the results as a 3-D anatomical scene. The system promises potential practical utility for obtaining and navigating spatial and symbolic data.