Mesenteric fibromatosis mimicking a gastrointestinal stromal tumor.

Mesenteric fibromatosis is a locally aggressive tumor of the mesentery with a high propensity for bowel involvement. Mesenteric fibromatosis often mimics gastrointestinal stromal tumors in size, location and immunohistochemical features. We report the case of a 30-year-old male who underwent resection of a mesenteric tumor, initially diagnosed as gastrointestinal stromal tumor. The tumor was categorized as high-risk and the patient was treated with chemotherapy. Two years later the patient was found to have a mass in the mesentery and restarted on chemotherapy. The tumor did not respond to medical management. The patient underwent a second en bloc resection and pathology results were conclusive for mesenteric fibromatosis. This case highlights the significance of accurately differentiating mesenteric fibromatosis from gastrointestinal stromal tumor. Making a concrete diagnosis is often difficult because both gastrointestinal stromal tumors and mesenteric fibromatosis share a number of morphological and immunohistochemical features including CKIT expression.

Right ventricle-sparing heart transplantation effective against iatrogenic pulmonary hypertension.

BACKGROUND: Right heart failure is the predominant cause of death following heart transplantation, occurring with disturbingly high frequency in patients with severe antecedent pulmonary hypertension. We have recently reported a novel technique of heart transplantation that spares the recipient right ventricle, excising only the recipient left ventricle. The resulting model has 2 right hearts and 1 left heart. The aim is to preserve the recipient's right ventricle, which is already conditioned to pulmonary hypertension. The hope is that, in this way, death due to right heart failure can be prevented in humans. Our prior report was a feasibility study in normal dogs. This study challenges this new technique by creating iatrogenic pulmonary hypertension in the recipient animals. METHODS: Iatrogenic pulmonary hypertension was created in 4 recipient canines by intravenous injection of the pulmonary toxin monocrotaline pyrrole (single bolus of 3.5 to 4.5 mg/kg intravenously [i.v.]). RESULTS: Within 6 weeks of monocrotaline administration, relative pulmonary hypertension occurred (mean pulmonary artery [PA] pressure 20 mm Hg vs 10 mm Hg for controls [p < 0.01]) (pulmonary vascular resistance [PVR] 4.2 vs 1.5 Wood units [P < 0.01]), and right ventricular (RV) hypertrophy developed (RV thickness 11 mm vs 2 mm [P < 0.04]). Histologic examination confirmed severe muscle infiltration and thickening of the media of the pulmonary arterioles. RV-sparing heart transplantation was performed successfully in all 4 animals with pulmonary hypertension. In all cases, the animals were weaned without difficulty from cardiopulmonary bypass, despite the ambient pulmonary hypertension, on low-dose epinephrine, maintaining systolic blood pressure of 104 mm Hg at right atrial pressure of 7 mm Hg. Both right hearts contracted well without dilation or strain. A single "control" traditional orthotopic transplant experiment in an animal with monocrotaline-induced pulmonary hypertension resulted in immediate death from right heart failure. CONCLUSIONS: Right ventricle-sparing heart transplantation ("one-and-one-half heart model") can handle pulmonary hypertension without difficulty. This evidence adds impetus for further pursuing of right ventricle-sparing heart transplantation to decrease the incidence of death from right heart failure in recipients with severe antecedent pulmonary hypertension.

Novel technique for isolated accessory right heart transplantation for congenital heart disease.

BACKGROUND: Our prior laboratory work has permitted adding a whole donor heart to a preserved recipient right heart, producing a heart-and-a-half preparation able to cope with pulmonary hypertension in the recipient. The experiments in the present study explore the feasibility of the converse operation: adding an isolated donor right heart to an entire preserved heart. METHODS: Eight adult mongrel dogs (4 donors and 4 recipients) were used in 4 transplant operations performed through a right thoracotomy without cardiopulmonary bypass (using side-biting control of recipient vessels). The donor heart underwent resection of the left atrium and left ventricle, leaving an isolated donor right heart. Blood supply to the donor right ventricle was preserved from the donor ascending aorta. Through a right thoracotomy, the donor right heart was transplanted in parallel to the native right heart of the recipient by using the following anastomoses: (1) donor superior vena cava to recipient superior vena cava (end-to-side anastomosis); (2) donor pulmonary artery to recipient pulmonary artery (end-to-side anastomosis); (3) donor ascending aorta to recipient aorta (through a great vessel [end-to-end anastomosis] to provide arterial inflow to donor coronary arteries). Animals were euthanized within 1 hour after completion of transplantation. RESULTS: Isolation of the right ventricle by excision of the left chambers was technically feasible. Transplantation without cardiopulmonary bypass was feasible in all cases. The isolated right heart beat well after transplantation in all animals, demonstrating sinus rhythm. Three of 4 animals were able to sustain good hemodynamics on support with epinephrine. Bleeding from the septum or aortic valve of the donor (now open to the pericardial space) was not problematic. Mean arterial pressure was 85 mm Hg (mean) at a right atrial pressure of 6 mm Hg (mean). In 2 animals the recipient superior vena cava was ligated to obligate upper body flow to pass through the accessory ventricle; hemodynamics were preserved under these circumstances. CONCLUSION: Transplantation of an isolated right heart is feasible. Such a technique has potential as a novel therapeutic alternative for obstructive or hypoplastic lesions of the right heart in human children.

Midterm follow-up of penetrating ulcer and intramural hematoma of the aorta.

OBJECTIVE: Most studies on variant forms of aortic dissection--penetrating ulcer and intramural hematoma--have focused on the initial presenting episode, with scant follow-up. This investigation provides midterm follow-up of penetrating ulcer and intramural hematoma to determine whether the aorta shows healing according to radiography, goes on to dilate, or tends to rupture during later follow-up. METHODS: Forty-five patients with penetrating ulcers (n = 26) or intramural hematomas (n = 19) were treated at our institution. Ten patients with penetrating ulcers were male and 16 were female, and their ages ranged from 54 to 87 years (mean 72 years). Eight patients with intramural hematomas were male and 11 were female, and their ages ranged from 54 to 88 years (mean 74 years). These patients all had symptoms of aortic disease. Patients with incidental imaging findings were not considered. RESULTS: In the group with penetrating ulcers, rupture occurred during the initial admission in 10 (38%) cases, 17 patients (65%) underwent surgery, and 22 patients (85%) survived to hospital discharge. Among those with intramural hematomas, rupture occurred during the initial admission in 5 cases (26%), 7 patients (37%) underwent surgery, and 16 patients (84%) survived to hospital discharge. Follow-up ranged from 1 month to 12.5 years (mean 3.4 years). No ischemic vascular complications occurred. Imaging follow-up was available for 26 of the 45 patients. Of these, 19% of lesions showed resolution, 23% had worsened, 39% had progressed to typical dissection, and 19% were unchanged. Six late deaths were known to be caused by rupture. In the group with penetrating ulcers, aortic diameter increased from 4.8 to 5.1 cm during the course of 14 months. In the group with intramural hematomas, aortic diameter increased from 5.3 to 5.9 cm during the course of 21 months. Overall survivals were 80% at 1 year, 73% at 3 years, and 66% at 5 years. CONCLUSIONS: Intramural hematoma and penetrating ulcer are lesions associated with advanced age. Women predominate. Penetrating ulcer and intramural hematoma rupture both early and late. Radiographically documented worsening, improvement, or frank dissection may occur with time. Aortic growth does occur (0.2 cm per year for penetrating ulcer and 0.4 cm per year for intramural hematoma). Vascular ischemic complications do not occur. Because of the high early rupture rate, the frequency of radiographic worsening, and the documented occurrence of late rupture, we now recommend surgical replacement of the aorta for these virulent vascular lesions as long as the patient's comorbidities do not preclude surgical intervention.

Alternate technique for implantation of left ventricular assist system: left thoracotomy for reoperative cases.

Reoperation for Novacor left ventricular assist device placement after prior cardiac surgery is fraught with multiple technical challenges. We have found that a thoracotomy approach obviates these dangers very favorably. The technique is performed off bypass except for apical coring and apical connection. Novacor outflow is to the descending aorta. This approach has been found safe, quick, and effective.

Yearly rupture or dissection rates for thoracic aortic aneurysms: simple prediction based on size.

BACKGROUND: Prior work has clarified the cumulative, lifetime risk of rupture or dissection based on the size of thoracic aneurysms. Ability to estimate simply the yearly rate of rupture or dissection would greatly enhance clinical decision making for specific patients. Calculation of such a rate requires robust data. METHODS: Data on 721 patients (446 male, 275 female; median age, 65.8 years; range, 8 to 95 years) with thoracic aortic disease was prospectively entered into a computerized database over 9 years. Three thousand one hundred fifteen imaging studies were available on these patients. Five hundred seventy met inclusion criteria in terms of length of follow-up and form the basis for the survival analysis. Three hundred four patients were dissection-free at presentation; their natural history was followed for rupture, dissection, and death. Patients were excluded from analysis once operation occurred. RESULTS: Five-year survival in patients not operated on was 54% at 5 years. Ninety-two hard end points were realized in serial follow-up, including 55 deaths, 13 ruptures, and 24 dissections. Aortic size was a very strong predictor of rupture, dissection, and mortality. For aneurysms greater than 6 cm in diameter, rupture occurred at 3.7% per year, rupture or dissection at 6.9% per year, death at 11.8%, and death, rupture, or dissection at 15.6% per year. At size greater than 6.0 cm, the odds ratio for rupture was increased 27-fold (p = 0.0023). The aorta grew at a mean of 0.10 cm per year. Elective, preemptive surgical repair restored life expectancy to normal. CONCLUSIONS: This study indicates that (1) thoracic aneurysm is a lethal disease; (2) aneurysm size has a profound impact on rupture, dissection, and death; (3) for counseling purposes, the patient with an aneurysm exceeding 6 cm can expect a yearly rate of rupture or dissection of at least 6.9% and a death rate of 11.8%; and (4) elective surgical repair restores survival to near normal. This analysis strongly supports careful radiologic follow-up and elective, preemptive surgical intervention for the otherwise lethal condition of large thoracic aortic aneurysm.