Masahisa Masuda

Long-term outcome after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

OBJECTIVES Pulmonary endarterectomy is the treatment of choice for chronic thromboembolic pulmonary hypertension. Although several reports demonstrated excellent medium-term survival after pulmonary endarterectomy, long-term outcomes remain unclear. We reviewed long-term outcomes and determined risk factors for early and late adverse events. METHODS Seventy-seven patients were studied. Mean pulmonary arterial pressure was 47±10 mm Hg and pulmonary vascular resistance was 868±319 dyne·s·cm(-5). Disease was classified as chronic thromboembolic pulmonary hypertension type 1 (n=61), type 2 (n=12), or type 3 (n=4). Median and maximum follow-up periods were 5.6 and 20 years, respectively. RESULTS There were 11 in-hospital deaths. Nonsurvivors had significantly higher mean pulmonary arterial pressure and pulmonary vascular resistance than did survivors (54±10 vs 46±10 mm Hg; P=.02; 1124±303 vs 824±303 dyne·s·cm(-5); P<.01). In multivariate analysis, preoperative pulmonary vascular resistance was associated with in-hospital death (odds ratio, 1.003; 95% confidence interval, 1.001-1.005; P<.01). During follow-up, there were 10 all-cause deaths, including 5 related to chronic thromboembolic pulmonary hypertension. Freedom from adverse events, including disease-specific death or New York Heart Association functional class III, was 70% at 10 years. In the Cox proportional hazard model, postoperative mean pulmonary arterial pressure was associated with adverse events (hazard ratio, 1.12; 95% confidence interval, 1.03-1.21; P<.01). Receiver operating characteristic curve analysis showed mean pulmonary arterial pressure of 34 mm Hg as cutoff for adverse events. CONCLUSIONS Pulmonary endarterectomy had sustained favorable effects on long-term survival. High pulmonary vascular resistance was associated with in-hospital death, and postoperative mean pulmonary arterial pressure was an independent predictor of adverse events.

A new method for the treatment of graft infection in the thoracic aorta: in situ preservation

BACKGROUND We have developed a new method to control graft infection by a combination of two procedures, extensive disinfection followed by tissue flap implantation, allowing preservation of the original graft. METHOD Soon after the diagnosis of graft infection was confirmed, the wound was re-explored, and debridement, irrigation and packing with sponges soaked with 10% iodine solution were employed. This procedure was repeated every 8 hours for the first 48 hours. For the second step, tissue flaps using omentum or muscle were implanted around the graft as well as in dead space, and the wound was closed primarily. MATERIALS A total of 6 patients were treated: 4 in the acute and 2 in the chronic phase of infection. The original procedures were a Bentall procedure + arch replacement (1), ascending aorta replacement + arch (3) and replacement of the descending aorta (2). In descending aorta cases, an extended thoracoplasty was concomitantly added to eliminate dead space in the pleural cavity. RESULTS Graft infections were controlled in all 6 patients. One hospital death unrelated to infection was encountered. Five patients were discharged, but 1 died of a stent-graft complication. The follow-up period ranged from 4 months to 10 years. CONCLUSION Our method of extensive disinfection followed by tissue flap coverage of the graft proved to be highly effective in controlling the serious complication of graft infection associated with surgery of the thoracic aorta.

Characterization of myofibroblasts in chronic thromboembolic pulmonary hypertension

BACKGROUND It has been generally accepted that chronic thromboembolic pulmonary hypertension (CTEPH) results from pulmonary embolism arising from deep vein thrombosis. An unresolved question regarding the etiology of CTEPH is why pulmonary thromboemboli are stable and resistant to effective anticoagulation. Recently non-resolving pulmonary thromboemboli in CTEPH have been shown to include myofibroblasts. This study investigates the cellular characteristics of myofibroblasts included in the organized thrombotic tissues of CTEPH. METHODS Organized thrombotic tissues of patients with CTEPH were obtained following pulmonary endarterectomy. We isolated cells from endarterectomized tissue from patients with CTEPH and identified them as endothelial-like cells and myofibroblast-like cells. RESULTS Myofibroblast-like cells were characterized as hyperproliferative, anchorage-independent, invasive and serum-independent. CONCLUSIONS Here we report the presence of active myofibroblast-like cells in endarterectomized tissue of CTEPH. We suggest that the formation of myofibroblasts with a high growth potential in the organized thrombotic tissues may be an important event in the pathobiology of this disease.

A chronic contained rupture of an abdominal aortic aneurysm complicated with severe back pain

Chronic contained rupture of an abdominal aortic aneurysm is an uncommon occurrence with the aneurysms usually small-to-moderate in size. Diagnosis may be difficult because patients present with both atypical and chronic symptoms. Pressure erosion of the lumbar spine is presumably a highly significant associated disorder, but an enhanced computed tomographic scan is the most reliable method for the correct diagnosis. We report on a 46-year-old man who developed severe back pain which was initially thought to result from spinal disease. Retrospective review of computed tomographic scans taken two years before admission revealed the beginning of the leakage of the aneurysm. Remarkably, the patient remained stable two years after the rupture.

Subpleural Perfusion as a Predictor for a Poor Surgical Outcome in Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND Small vessel disease is a major determinant of poor outcome after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension (CTEPH). Out-of-proportion pulmonary vascular resistance (PVR) may indicate the presence of small vessel disease, but it is a very subjective evaluation. We investigated poor subpleural perfusion as a marker for small vessel disease and assessed its association with disease severity and surgical outcome of CTEPH. METHODS We assessed the subpleural perfused area in the capillary phase of pulmonary angiography in 104 consecutive patients, including 45 who underwent surgery, and then divided the patients into either the well-perfused group (the subpleural space in at least one segment was well perfused [n = 75]) or the poorly perfused group (subpleural spaces were either unperfused or minimally perfused in all segments [n = 29]). We compared the pulmonary hemodynamics, degree of distal thrombi, and surgical outcome between these two groups. RESULTS The poorly perfused group had significantly higher PVR (937 ± 350 dyne/s/cm(5) vs 754 ± 373 dyne/s/cm(5), P = .02) and more distal thrombi, resulting in fewer surgically treated patients (27.6% vs 49.3%, P = .04) compared with the well-perfused group. This group showed a higher surgical mortality (62.5% vs 2.7%) and higher postoperative PVR (656 ± 668 dyne/s/cm(5) vs 319 ± 223 dyne/s/cm(5), P = .04). Even in a multivariate analysis, poor subpleural perfusion was associated with surgical mortality. CONCLUSIONS Poor subpleural perfusion in the capillary phase of pulmonary angiography might be related to small vessel disease and a poor surgical outcome of CTEPH.

Aortic Arch Operation Using Selective Cerebral Perfusion for Nondissecting Thoracic Aneurysm

BACKGROUND Risks of increasing mortality and disability in aortic arch operations using the selective cerebral perfusion method for nondissecting aneurysm have not yet been determined. A multicenter, retrospective study was employed. METHODS The subjects were 143 patients who were admitted to one of the nine cardiovascular centers between January 1988 and December 1993, including 15 with ruptured aneurysm. A graft replacement of the transverse aortic arch or distal arch was performed in 80 patients, extensive aortic reconstruction comprising simultaneous replacement of the ascending or descending thoracic aorta (or both) in 46, and patch repair of involved arch in 17. The mean postoperative follow-up period was 19 months. RESULTS Hospital mortality was 36/143 patients (25.2%). Univariate analysis revealed that age of 70 years or more, ruptured aneurysm, and renal dysfunction affected hospital mortality. Neurologic deficits were noted in 15 patients (10.5%). Reoperation was performed in 13 patients for residual distal aneurysm or false aneurysm. Late death occurred in 10 patients and were due to vascular complications in 6. Multivariate analysis confirmed that aneurysmal rupture and renal dysfunction were independent predictors for vascular death including hospital mortality. CONCLUSIONS The present study confirmed that age, aneurysmal rupture, and renal dysfunction were significant predictors for mortality and disability in the aortic arch operation using selective cerebral perfusion for nondissecting thoracic aneurysm.

Operation for Nondissecting Aneurysm in the Descending Thoracic Aorta

BACKGROUND Little is known about the risks of mortality and morbidity after descending thoracic aortic aneurysm repair using left heart bypass and temporary arterioarterial bypass. METHODS A multicenter, retrospective study was performed on 120 patients who were admitted to one of nine cardiovascular centers between January 1988 and December 1993 and underwent operation for nondissecting thoracic aortic aneurysm. The present series included 10 patients with ruptured aneurysm. Graft replacement was performed in 95 patients, patch repair in 22, and suture of the ruptured aorta in 3. Venoarterial bypass was used in 45 patients, left heart bypass in 56, and temporary arterioarterial bypass in 19 as circulatory support. The mean postoperative follow-up period was 30 +/- 21 months. RESULTS Hospital mortality occurred in 7 patients (5.8%). Univariate analysis revealed that only aneurysmal rupture was related to hospital mortality. Brain or cord injury was observed in 4. Of nine deaths that occurred after discharge, five were related to aneurysm and two were due to vascular event. No significant difference was noticed in probability of survival according to the circulatory supporting method. Only aneurysmal rupture affected probability of survival. Multivariate analysis revealed that aneurysmal rupture was the only independent predictor for vascular death including hospital mortality. CONCLUSIONS The present study confirms that aneurysmal rupture is a significant predictor for mortality and morbidity in aortic operations for nondissecting descending thoracic aneurysm, and that a similarly good outcome would be expected when using left heart bypass, temporary arterioarterial bypass, or venoarterial bypass.

Mid-term results of surgery for chronic thromboembolic pulmonary hypertension

Pulmonary thromboendarterectomy is an effective surgical treatment for chronic thromboembolic pulmonary hypertension (CTEPH). In this study, we review our short- and mid-term results in the recent series of patients undergoing pulmonary thromboendarterectomy. Twenty-three patients (54+/-12 years) were re-evaluated 7-59 months (mean, 34 months) after surgery. Nine patients were in New York Heart Association functional class II, 11 patients in class III and three patients in class IV. All patients used supplemental oxygen therapy. After surgery, pulmonary hemodynamics were significantly improved: pulmonary vascular resistance (PVR) decreased from 925+/-342 to 337+/-260 dynes x s x cm(-5) (P<0.01); mean pulmonary artery pressure (MPAP) decreased from 47+/-12 to 25+/-10 mmHg (P<0.01). Three patients developed severe residual pulmonary hypertension and one of them died soon after surgery. During the follow-up period there were no deaths, but one recurrence of pulmonary embolism. Nineteen patients (86%) were in New York Heart Association functional class I or II and thirteen patients (59%) were weaned from oxygen therapy. In conclusion, pulmonary thromboendarterectomy provided remarkable early and late results with acceptable hospital mortality rate, normalization of pulmonary hemodynamics, and improvement in clinical functional status with relief of hypoxemia.

Successful pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension associated with anticardiolipin antibodies : report of a case

Chronic pulmonary thromboembolism with pulmonary hypertension is a rare but most unique syndrome in the broad spectrum of pulmonary embolism. This report describes a successful pulmonary thromboendarterectomy performed for a totally occluded right pulmonary artery on a 43 year old man who presented with positive cardiolipin antibodies. The surgery was performed through a median sternotomy with cadiopulmonary bypass and intermittent periods of deep hypothermic circulatory arrest. We are convinced that this method allows for complete removal of the thrombotic obstruction and should be the procedure of choice for patients with very proximal obstruction of a pulmonary artery.

Thromboendarterectomy for Severe Chronic Thromboembolic Pulmonary Hypertension

Pulmonary thromboendarterectomy is a curative surgical procedure for chronic thromboembolic pulmonary hypertension. The aim of this study was to clarify whether severe hemodynamic compromise affects surgical outcome. We studied 19 patients who underwent pulmonary thromboendarterectomy and compared 11 with pulmonary vascular resistance < 1,000 dyne·s·cm−5 (group 1) and 8 with pulmonary vascular resistance > 1,000 dyne·s·cm−5 (group 2). Mean pulmonary artery pressure and pulmonary vascular resistance decreased significantly after surgery in both groups. The incidence of postoperative complications did not differ between groups; however, one patient in group 2 died of multiorgan failure. The overall mortality rate was 5.3%, and the rate in group 2 was 13%. Our results indicate that preoperative hemodynamic compromise does not affect surgical outcome. Patients with high pulmonary vascular resistance can be treated effectively by thromboendarterectomy, with acceptable morbidity and mortality.