Latissimus dorsi dynamic cardiomyoplasty of the right ventricle. Potential for use as a partial myocardial substitute.

Full-thickness right ventricular latissimus dorsi dynamic cardiomyoplasty with the Medtronic Cardiomyostimulator (Medtronic, Inc., Minneapolis, Minn.) was performed in a chronic canine model. In one group (n = 2) the latissimus dorsi was electrically preconditioned before cardiomyoplasty. In a second group (n = 3) cardiomyoplasty was performed and the muscle was progressively stimulated, with conditioning accomplished while the latissimus dorsi was functioning on the ventricle. The contribution of the stimulated latissimus dorsi to global ventricular function was assessed, and the effects of varying muscle stimulation parameters on latissimus dorsi function and hemodynamics were examined. Right ventricular systolic pressure increased 8%, from 23.2 +/- 0.95 to 25.1 +/- 1.5 mm Hg. The rate of pressure rise increased 37% from 226 +/- 13 to 309 +/- 12 mm Hg/sec. Right ventricular ejection fraction was measured in two dogs and increased 29% with latissimus dorsi stimulation, from 51.5% +/- 13.5% to 66.5% +/- 14.5%. Although the sample size was small, there was no difference observed between the preconditioned and nonpreconditioned groups. Right ventricular systolic pressure, rate of pressure rise, and percent latissimus dorsi fiber shortening increased as voltage and burst frequency of the muscle stimulus increased, whereas increasing the burst duration had little effect in two dogs so studied. Latissimus dorsi dynamic cardiomyoplasty can function as a partial myocardial replacement in a chronic canine model, apparently without preconditioning of the muscle. The degree of cardiac assist obtained with cardiomyoplasty appears to be influenced by the voltage and frequency of the stimulus applied to the muscle. Although it is unclear whether these results can be extrapolated to the left ventricle, this technique may find application in the treatment of ventricular aneurysm or ventricular tumor.

Extracorporeal irradiation of tumorous calvaria. Case report.

This patient with recurrent meningioma grossly involving the frontal bone underwent craniotomy and tumor resection. During the procedure a bone flap was irradiated extracorporeally at a very high dose (120 Gy) sufficient to sterilize residual tumor cells, and the bone was then successfully replaced orthotopically for reconstruction. The use of autologous irradiated bone in this setting offers advantages over cadaveric transplantation and prosthetic implants. Radiation might cause less disruption of the bone's architecture than other techniques of tumor cell eradication.

Closure of craniofacial defects after cancer resection.

Resection of malignancies of the upper face and skull base may result in complex bone and soft tissue defects. To better define the optimal management of these defects, we conducted a retrospective review of 75 consecutive patients who underwent closure of 76 craniofacial defects after malignant tumor excision from 1966 to 1990. Wound complications requiring further surgery occurred in 30% of the defects (23 of 76). Wound complications at anterior, temporal, or combined sites were correlated with each method of reconstruction (scalp flap or split thickness skin graft, pedicled myocutaneous flap, and free flap). The presence of a large combined defect involving both frontal and temporal areas was the only significant risk factor for development of a wound complication requiring secondary surgery. These data suggest that anterior or temporal craniofacial defects may be closed with either scalp flaps and split thickness skin grafts or pedicled myocutaneous flaps with reasonable wound complication rates of 16% to 22%. Large combined defects have high wound complication rates (90%) when local tissue is used; therefore, other methods of closure such as free tissue transfer should be strongly considered in these patients.

Intraosseous vascular malformations of the orbit.

Intraosseous vascular malformations are rare benign tumors involving the bones of the orbit. The diagnosis should be considered when a patient presents with an enlarging mass fixed to bone in the upper face, and the characteristic x-ray appearance should be looked for on plain films. Treatment is local excision of the bone containing the tumor and immediate reconstruction with autogenous bone.

Use of the omentum in the management of sternal wound infection after cardiac transplantation.

Seven patients with deep sternal wound infection after orthotopic cardiac transplantation were treated at the Medical College of Virginia-McGuire Veterans Administration Hospitals over a 3-year period. Six patients had mediastinitis with pericardial abscess, and one patient had only sternal osteomyelitis. All patients underwent prompt sternal debridement. In the six patients with mediastinitis, the transplanted heart was surrounded by a large dead space after debridement. This space appeared to result from a size mismatch between the remaining enlarged pericardial sac and the new normal-sized transplanted heart. Wound closure was done at the time of debridement in all patients except one who was closed 3 days later. A pedicled omental flap based on the right gastroepiploic artery was used in five of the six patients with mediastinitis, and these five patients healed their wounds and resolved their infection. Three of these patients are alive and well and two died of later complications other than sternal infection. The patient with only sternal osteomyelitis healed uneventfully. When mediastinitis and intrapericardial infection is present after cardiac transplantation, the omentum appears to provide adequate bulk for obliteration of the large dead space that remains after debridement. This surgery, combined with antibiotic therapy and temporary reduction of immunosuppression, can treat sternal wound infection successfully after cardiac transplantation. Mortality from other complications can occur, however, and not all patients survive.

Computed tomography findings in patients who have undergone muscle flap and omental transposition procedures in the treatment of poststernotomy mediastinitis.

We studied computed tomographic (CT) appearance of muscle or omental flap transposition procedures in ten patients following clinically diagnosed poststernotomy mediastinitis. Patients were examined either to rule out persistent infection or as part of routine follow-up. An increased amount of soft tissue between open sternal fragments and deformity or apparent "absence" of the utilized muscle were normal postoperative anatomic alterations. Abscess within the flap was diagnosed in one patient who had an abnormal focus of low attenuation in the muscle bundle and scattered air bubbles. An overview with CT correlation of the technical aspects of the reconstructive procedures performed at our institution is provided.

Results of cranial vault reshaping.

This study was designed to assess the outcome of cranial vault reshaping for correction of deformity of the skull and the upper face. A retrospective review of all children who underwent cranial vault reshaping by a single team of surgeons between 1993 and 1996 was performed. There were 10 children in the series. The age at surgery ranged from 6 to 62 months (mean age, 25 months). Five children in the series had untreated sagittal craniosynostosis with scaphocephaly, two had pansynostosis resulting in cloverleaf skull deformity, and three had turricephaly after shunt treatment of hydrocephalus. There was no operative mortality. Blood loss ranged from 250 to 1,500 ml (mean, 422 ml). All patients needed transfusion. There were two major complications resulting from increased intracranial pressure, but both patients recovered completely with no neurological sequelae. Titanium plates and screws were used in all patients, but were removed in two when they became palpable. The 5 children with sagittal craniosynostosis had a normal head shape. The 2 children with cloverleaf skull have improved head shape with persistent increased bitemporal width and round faces. The 3 children with turricephaly after shunting have marked improvement with mild persistent deformity. This study shows that cranial vault reshaping is safe and can lead to a long-term normal head shape in children with late correction of sagittal craniosynostosis. Children with more severe anomalies, particularly syndromic patients, can be improved but will have persistent mild deformity.

Forehead reconstruction with a modified radial forearm flap: a case report.

Forehead reconstruction, using a radial forearm flap with opposing long arterial and venous pedicles, is presented. Advantages of this flap design are discussed.

The role of pressure on regulation of craniofacial bone growth.

The regulatory role of pressure on growth and differentiation of the craniofacial skeleton is largely unknown. We devised an experimental model to determine if the graded application of pressure could exert a trophic influence on craniofacial bone, allowing deliberate alteration and reshaping of the facial skeleton. To examine this question, 18 kittens were used to determine the adverse morphological sequelae after orbital evisceration and to compare the ability to remedy such facial deformity with the use of an inert implant or pressure-induced tissue expansion. In addition to detailed craniometric measurements of the cranial, orbital, and midfacial regions, histological analyses as well as radiographic and gross morphological comparisons were evaluated. Our results demonstrate a severe asymmetry and constriction in the orbital and midfacial regions resulting from orbital evisceration in the growing kitten. Placement of an inert implant will help to ameliorate only some of these adverse sequelae, whereas graded application of pressure appears to direct craniofacial bone growth, resulting in normal bony histology and improved facial form. We affirm that regional growth disturbances can alter normal facial development and that the regulatory role of pressure on bone growth can be exploited to dynamically correct abnormal craniofacial anatomy.

Surgery as palliative treatment for distant metastases of melanoma.

Sixty-five patients with distant metastatic melanoma amenable to surgical treatment had excision of 94 metastatic lesions from the brain, lung, abdomen, distant subcutaneous sites, and distant lymph nodes. Relief of symptoms, if present, was obtained after excision of 77% of brain metastases, 100% of lung metastases, 88% of distant lymph node and subcutaneous metastases, and 100% of abdominal metastases. Median survival after excision of brain metastases was 8 months, lung metastases 9 months, abdominal metastases 8 months, and distant subcutaneous and lymph node metastases 15 months. Sixteen per cent of patients lived for 2 years of longer. These results demonstrated that surgery can achieve an effective local disease control in selected patients with distant melanoma metastases and that a few have a relatively long-term survival.