Heterotopic en bloc tracheobronchial transplantation with direct revascularization in pigs

OBJECTIVE: This article describes the application of a novel aortic tube technique for directly revascularized tracheobronchial transplantation with dual blood supply in pigs. METHODS: Eleven adult Large White pigs underwent heterotopic tracheal transplantation with a dual revascularization technique (inferior thyroid artery and bronchial artery). Seven tracheobronchial grafts were perfused ex vivo, and hemodynamic data were collected. RESULTS: At the last evaluation, 6 pigs had normally epithelialized mucus-producing allografts with correct morphologic conformation and cartilage viability. The histopathologic examination revealed homogeneous tissue regardless of biopsy site (trachea, carina, or bronchi), demonstrating the efficacy of the revascularization procedure. Four animals had early ischemic necrosis develop, 2 from acute rejection and 2 from technical mishap. One additional pig had acute rejection starting on the 14th postoperative day. The CD4(+)/CD8(+) ratio was maintained close to or above 0.8 in the subgroup with rejection and below 0.6 in the animals that were correctly immunosuppressed. Pressure-flow curves in 7 ex vivo tracheobronchial grafts showed a nonsignificant difference (P <.12) in vascular resistance between the bronchial artery territory (lower resistance) and the inferior thyroid artery territory. CONCLUSIONS: For the first time, a transplantation technique encompassing the entire trachea, carina, and stem bronchi has been made possible. By means of the dual inferior thyroid and bronchial artery axis, we were able to obtain a structurally healthy and functional graft to replace the main airway.     

Pheochromocytomas: detection with 18F DOPA whole body PET--initial results.

PURPOSE: To evaluate fluorine 18 ((18)F) dihydroxyphenylalanine (DOPA) whole-body positron emission tomography (PET) as a biochemical imaging approach for detection of pheochromocytomas. MATERIALS AND METHODS: (18)F DOPA PET and magnetic resonance (MR) imaging were performed in 14 consecutive patients suspected of having pheochromocytomas (five sporadic, nine with von Hippel-Lindau disease); metaiodobenzylguanidine (MIBG) scintigraphy was performed in 12 of these patients. The individual imaging findings were assessed in consensus by specialists in nuclear medicine and radiologists blinded to the results of the other methods. The findings of the functional imaging methods were compared with those of MR imaging, the reference standard. Histologic verification could be obtained in eight patients with nine tumors. RESULTS: Seventeen pheochromocytomas (11 solitary, three bifocal; 14 adrenal, three extraadrenal) were detected with MR imaging. (18)F DOPA PET and MR imaging had concordant results in all 17 tumors. In contrast, MIBG scintigraphy had false-negative results in four patients with three adrenal tumors smaller than 2 cm and one extraadrenal tumor with a diameter of 3.6 cm. On the basis of these data, sensitivities of 100% for (18)F DOPA PET and of 71% for MIBG scintigraphy were calculated. Specificity was 100% for both procedures. CONCLUSION: (18)F DOPA PET is highly sensitive and specific for detection of pheochromocytomas and has potential as the functional imaging method of the future.     

Sclerosed liver hemangioma mimicking malignant tumor at MR imaging: Pathologic correlation

This case report illustrates atypical magnetic resonance (MR) imaging findings in a liver hemangioma mimicking a malignant lesion—lower signal intensity than cerebrospinal fluid on T2-weighted spin-echo images and lack of early enhancement on dynamic contrast material—enhanced gradient-echo images. Pathologic analysis demonstrated nearly total replacement of the vascular cavities by dense fibrous tissue. In this rare, sclerosed form, this lesion could not be defined as a hemangioma with MR imaging.     

In vivo comparison of two through-plane MR velocity mapping methods: Fast fourier encoding and phase mapping

Magnetic resonance imaging maps of velocity were acquired with a 1.5-T system in 10 subjects in a plane perpendicular to the main pulmonary artery. Velocity images were successively acquired with a method developed from Fourier-encoding velocity imaging (FEVI) principles with eight gradient steps and one excitation, and with two-point phase-subtraction mapping. Reconstruction in FEVI was implemented by zero-filling interpolation around the eight gradient steps and then around the four central steps. The methods were compared by using estimates of noise in velocity measurements based on the difference between the experimental map and a smooth fitted map. For the same acquisition time, FEVI with four encoding steps was more precise in velocity measurements than phase mapping. Precision was further increased by the use of eight encoding steps, but acquisition time was doubled.     

In-stent recurrent stenosis after carotid artery stenting: life table analysis and clinical relevance

OBJECTIVES: Carotid artery stenting has been proposed as an alternative to carotid endarterectomy in cerebral revascularization. Although early results from several centers have been encouraging, concerns remain regarding long-term durability of carotid artery stenting. We report the incidence, characteristics, and management of in-stent recurrent stenosis after long-term follow-up of carotid artery stenting. METHODS: Carotid artery stenting (n = 122) was performed in 118 patients between September 1996 and March 2003. Indications included recurrent stenosis after previous carotid endarterectomy (66%), primary lesions in patients at high-risk (29%), and previous ipsilateral cervical radiation therapy (5%). Fifty-five percent of patients had asymptomatic stenosis; 45% had symptomatic lesions. Each patient was followed up with serial duplex ultrasound scanning. Selective angiography and repeat intervention were performed when duplex ultrasound scans demonstrated 80% or greater in-stent recurrent stenosis. Data were prospectively recorded, and were statistically analyzed with the Kaplan-Meier method and log-rank test. RESULTS: Carotid artery stenting was performed successfully in all cases, with the WallStent or Acculink carotid stent. Thirty-day stroke and death rate was 3.3%, attributable to retinal infarction (n = 1), hemispheric stroke (n = 1), and death (n = 2). Over follow-up of 1 to 74 months (mean, 18.8 months), 22 patients had in-stent recurrent stenosis (40%-59%, n = 11; 60%-79%, n = 6; > or =80%, n = 5), which occurred within 18 months of carotid artery stenting in 13 patients (60%). None of the patients with in-stent recurrent stenosis exhibited neurologic symptoms. Life table analysis and Kaplan-Meier curves predicted cumulative in-stent recurrent stenosis 80% or greater in 6.4% of patients at 60 months. Three of five in-stent recurrent stenoses occurred within 15 months of carotid artery stenting, and one each occurred at 20 and 47 months, respectively. Repeat angioplasty was performed once in 3 patients and three times in 1 patient, and repeat stenting in 1 patient, without complications. One of these patients demonstrated asymptomatic internal carotid artery occlusion 1 year after repeat intervention. CONCLUSIONS: Carotid artery stenting can be performed with a low incidence of periprocedural complications. The cumulative incidence of clinically significant in-stent recurrent stenosis (> or =80%) over 5 years is low (6.4%). In-stent restenosis was not associated with neurologic symptoms in the 5 patients noted in this cohort. Most instances of in-stent recurrent stenosis occur early after carotid artery stenting, and can be managed successfully with endovascular techniques.     

Sleeve lobectomy for bronchogenic cancers: factors affecting survival

BACKGROUND: Sleeve lobectomy is a parenchyma-sparing procedure that is particularly valuable in patients with cardiac or pulmonary contraindications to pneumonectomy. The purpose of this study is to report our experience with sleeve lobectomy for bronchogenic cancer and to investigate factors associated with long-term survival. METHODS: Between January 1981 and June 2001, 169 patients underwent sleeve lobectomy for non-small-cell lung cancer (n = 139) or carcinoid tumor (n = 30), including 61 with a preoperative contraindication to pneumonectomy. Mean age was 59 +/- 14 years (range, 19 to 82 years). Vascular sleeve resection was performed in 11 patients. The remaining bronchial stump contained microscopic disease in 7 patients. RESULTS: Major bronchial anastomotic complications occurred in 6 (3.6%) patients: one was fatal postoperatively, three required reoperation, and two were managed conservatively. In the non-small-cell lung cancer group, operative mortality was 2.9% (4 of 139), and overall 5-year and 10-year survival rates were 52% and 28%, respectively. Six patients experienced local recurrence after complete resection. By multivariate analysis, two factors significantly and independently influenced survival: nodal status (N0 or N1 versus N2; p = 0.01) and microscopic invasion of the bronchial stump (p = 0.02). In the carcinoid tumor group, there were no operative deaths, and overall 5-year and 10-year survival rates were 100% and 92%, respectively. CONCLUSIONS: Sleeve lobectomy achieves local tumor control and is associated with low mortality and bronchial anastomotic complication rates. Long-term survival is excellent for carcinoid tumors. For patients with non-small-cell lung cancer, N2 disease or incomplete resection is associated with a worse prognosis; outcome is not affected by presence of a preoperative contraindication to pneumonectomy.     

Transcatheter arterial chemoembolization with or without radiofrequency ablation in the management of patients with advanced hepatic malignancy

Transcatheter arterial chemoembolization (TACE) is efficacious against hepatic malignancies by rendering tumors ischemic while delivering high-dose chemotherapy. The added benefit of radiofrequency ablation (RFA) has not been determined. We sought to review our experience with TACE with or without RFA in the treatment of hepatocellular carcinoma and colorectal liver metastases in patients not amenable to resection. TACE and RFA were undertaken in 13 patients with hepatocellular carcinoma (n = 7) or colorectal liver metastases (n = 6). Concurrently 24 patients underwent TACE alone for hepatocellular carcinoma (n = 15) or colorectal liver metastases (n = 9). Patients undergoing TACE with or without RFA were similar in age, gender, and diagnosis. Overall follow-up was 9.1 months +/- 7.1. One-year survival was greater in patients undergoing TACE with RFA than with TACE alone (100% vs 67%, P = 0.04). Mean survival was longer after TACE with RFA compared with TACE alone (25.3 months +/- 15.9 vs 11.4 months +/- 7.3, P < 0.05). No patients suffered significant complications. The addition of RFA to TACE improves survival in patients with unresectable primary or metastatic hepatic malignancies. RFA with TACE should be in the armamentarium of surgeons caring for patients with malignant liver lesions.     

Neoadjuvant chemotherapy for adult soft tissue sarcoma: comparaison of systemic and intra-arterial chemotherapy

Background

The introduction of a combined-modality approach, which added chemotherapy to local therapy (surgery and radiotherapy), has been controversial. We present our experience of the efficacy of neoadjuvant chemotherapy in patients with high-risk sarcomas and evaluate the benefit of intra-arterial (IA) chemotherapy.

Patients and methods

Forty patients with intermediate to high-grade soft tissue sarcomas (STS) were treated with neoadjuvant chemotherapy from 1994 to 2001 at the Institut Curie. Thirty-seven patients had localized tumours. Neoadjuvant intravenous (IV) chemotherapy consisted of 4–6 cycles of treatment (mainly CYVADIC, MAID). Sixteen patients (40%) received 2 cycles of IA chemotherapy with a combination of adriamycin and cisplatin. Radiotherapy was delivered in an adjuvant setting.

Results

All patients underwent limb-sparing surgical resection after neoadjuvant therapy and pathologic assessment of tumour necrosis was performed on the resected specimens. Two groups of tumours were analysed: 1–95% (28 cases), and 95–100% (10 cases) of pathological necrosis, with a survival benefit in the group with more than 95% necrosis (p = 0.07). IA chemotherapy was superior to IV chemotherapy in terms of the necrosis rate (p = 0.045). With a median follow-up of 51 months, the 2-year overall survival rate was 90% for localized tumours.

Conclusion

Neoadjuvant chemotherapy can be considered to be effective in the treatment of STS. This study demonstrates the benefit of neoadjuvant therapy for patients with a high necrosis rate (very clear tendency) and the contribution of IA chemotherapy to the response rate, but with no survival advantage.