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Biomedical subjects

A Khaghani

Publications and source records attributed to A Khaghani.

At least 37 records · Page 2Linked to original sources
PubMed1998

Pulmonary retransplantation: predictors of graft function and survival in 230 patients. Pulmonary Retransplant Registry.

BACKGROUND: Despite improving results in lung transplantation, a significant number of grafts fail early or late postoperatively. The pulmonary retransplant registry was founded in 1991 to determine the predictors of outcome after retransplantation. We hypothesized that ambulatory status of the recipient and center retransplant volume, which had been previously shown to predict survival after retransplantation, would also be associated with improved graft function postoperatively. METHODS: Two hundred thirty patients underwent retransplantation in 47 centers from 1985 to 1996. Logistic regression methods were used to determine variables associated with, and predictive of, survival and lung function after retransplantation. RESULTS: Kaplan-Meier survival was 47% +/- 3%, 40% +/- 3%, and 33% +/- 4% at 1, 2, and 3 years, respectively. On multivariable analysis, the predictors of survival included ambulatory status or lack of ventilator support preoperatively (p = 0.005; odds ratio, 1.62; 95% confidence interval, 1.15 to 2.27), followed by retransplantation after 1991 (p = 0.048; odds ratio, 1.41; 95% confidence interval, 1.003 to 1.99). Ambulatory, nonventilated patients undergoing retransplantation after 1991 had a 1-year survival of 64% +/- 5% versus 33% +/- 4% for nonambulatory, ventilated recipients. Eighty-one percent, 70%, 62%, and 56% of survivors were free of bronchiolitis obliterans syndrome at 1, 2, 3, and 4 years after retransplantation, respectively. Factors associated with freedom from stage 3 (severe) bronchiolitis obliterans syndrome at 2 years after retransplantation included an interval between transplants greater than 2 years (p = 0.01), the lack of ventilatory support before retransplantation (p = 0.03), increasing retransplant experience within each center (fifth and higher retransplant patient, p = 0.04), and total center volume of five or more retransplant operations (p = 0.05). CONCLUSIONS: Nonambulatory, ventilated patients should not be considered for retransplantation with the same priority as other candidates. The best intermediate-term functional results occurred in more experienced centers, in nonventilated patients, and in patients undergoing retransplantation more than 2 years after their first transplant. In view of the scarcity of lung donors, patient selection for retransplantation should remain strict and should be guided by the outcome data reviewed in this article.

Adolescent↗
PubMed1998

Medium term results of lung transplantation for end stage pulmonary sarcoidosis.

BACKGROUND: Lung transplantation is an accepted therapeutic option for patients with end stage pulmonary sarcoidosis. However, the medium term outcome of transplantation in this patient group is unknown. METHODS: This study was performed to evaluate our experience with lung transplantation for end stage pulmonary sarcoidosis. Between July 1988 and July 1997 12 patients (nine men) underwent lung transplantation for sarcoidosis at our institution. Ten underwent single lung transplantation and two double lung transplantation. RESULTS: Survival at three and five years was 70% and 56%, respectively. Three patients developed obliterative bronchiolitis at six, 18, and 45 months. One died at the time of retransplantation. Sarcoid granulomas have recurred in the donor organ in three patients. In one the development of granulomas has been associated with clinical deterioration, necessitating retransplantation. Mean (SD) forced expiratory volumes in one second at three and five years were 1.37 (0.67) 1 and 1.34 (0.13) 1, respectively. CONCLUSIONS: Lung transplantation is a viable option for patients with end stage pulmonary sarcoidosis. The medium term results are comparable with patients undergoing lung transplantation for other indications. Despite histological recurrence of sarcoidosis, the risk of clinically important recurrence is low.

Adult↗
PubMed1997

Angiotensin II receptor type 1 mRNA is upregulated in atria of patients with end-stage heart failure.

There is increasing evidence that pathological changes in the myocardium during chronic heart failure (CHF) are partly regulated through the activation of the renin-angiotensin system (RAS), an effect mediated by the angiotensin II type 1 receptor (AT1R). We examined the expression of cardiac AT1R mRNA in normal (atria, n=7; ventricle, n=3) and end-stage CHF human hearts (atria, n=8; ventricle, n=14). Tissue was snap-frozen immediately after explantation during orthotopic cardiac transplantation; control specimens were obtained from healthy donor hearts rejected for technical reasons. Northern blots of purified total mRNA from each tissue were hybridized with a random primed radiolabeled probe for the coding sequence of AT1R. Stringent conditions were used for both hybridization (5X SSC, 65 degrees C) and washing (0.5X SSC, 0.1% SDS, 65 degrees C) of the membrane. Left and right atrial tissue showed low levels of AT1R mRNA expression in the controls, with statistically significant upregulation of expression in tissue from pathological hearts; CHF atria 1.28+/-0.86 optical density (OD) units, control atria 0.56+/-0.31 OD units, P=0.05 (mean+/-s.d.). There were undetectable levels in ventricles from either control (2/2) or dilated hearts (7/7). The results were independent of the etiology of the heart failure and suggest that increased levels of atrial AT1R mRNA may occur in response to elevated atrial pressures in heart failure.

Adult↗
PubMed1997

Human en bloc double-lung transplantation: bronchial artery revascularization improves airway perfusion.

BACKGROUND: Ischemic airway complications are common after en bloc double-lung transplantation with tracheal anastomosis. The aim of this study was to evaluate the effects of a direct revascularization of the donor bronchial artery with the recipient internal thoracic artery on airway perfusion. METHODS: Seven patients undergoing double-lung transplantation with tracheal anastomosis were investigated intraoperatively and postoperatively (12 to 36 hours) with endoscopic laser Doppler flowmetry. Sixteen patients undergoing coronary artery bypass grafting served as a control group. RESULTS: Two patients who had double-lung transplantation with tracheal anastomosis died of sepsis and multiorgan failure 1 week after transplantation. In the remaining 5 patients healing of the anastomosis was excellent during the observation period of 3 to 52 months. In 5 patients clamping of the attached internal thoracic artery induced a reduction of the laser Doppler flowmetry signal from 10% to 60%. In the 2 patients with the highest graft perfusion level, no clamping effect could be detected. Compared with the control group, perfusion was significantly higher in the transplanted airways intraoperatively, at 71 versus 55 arbitrary perfusion units (p < 0.01). Postoperative transplant airway perfusion values were not significantly different from the intraoperative value. The coefficient of variation of repeated measurements was higher in the transplanted airways, with a coefficient of variation of 0.22 versus 0.17 in the control group (p < 0.01), indicating heterogeneous transplant airway perfusion. CONCLUSIONS: This study has documented that revascularization with the internal thoracic artery supplies the transplanted airway with additional oxygenated blood.

Anastomosis, Surgical↗
PubMed1997

Heterotopic cardiac transplantation in infants and children.

BACKGROUND: Children with advanced heart failure, particularly those with elevated pulmonary vascular resistance, pose a difficult management problem because the normal donor right ventricle cannot cope with the high pulmonary resistance and because of the relative shortage of donor organs of an appropriate size for this age group. METHODS: In an attempt to address these issues and evaluate the role of heterotopic transplantation in this context, we operated on 12 children, six boys and six girls, in the period between January 1, 1991, and March 31, 1996. Their ages ranged from 11 months to 15.2 years (mean 81.6 +/- 62.8 months) and their mean weight was 23.3 kg (range 7.6 to 56.8 kg). Eight patients (66.6%) had significant elevation of pulmonary artery pressure (pulmonary artery systolic pressure = 66 +/- 9.4 mm Hg, mean transpulmonary gradient = 22.3 +/- 3.4 mm Hg). In all patients the donor pulmonary artery was anastomosed to the recipient right atrium without the use of any prosthetic material. Ischemic times varied between 135 and 255 minutes (mean 182.1 +/- 30.7 minutes). The immunosuppression regimen included cyclosporine and azathioprine. Steroids were not routinely used. RESULTS: One patient died in the hospital of acute rejection on postoperative day 16. Three patients had lobe collapse within 1 week and all were treated successfully. Two late deaths (18.2%) occurred as a result of cardiac rejection 3 months and 2 years after the operations. Nine survivors (75%) are alive, active, and growing normally at a mean follow-up of 2.2 years (range 11 months to 4.75 years). Repeated cardiac catheterization performed in seven patients with preoperative pulmonary hypertension showed a slow progressive drop in mean pulmonary artery pressure. No significant change was observed in the function of the recipient hearts. CONCLUSION: We conclude that heterotopic heart transplantation is feasible for a selected group of children with good medium-term results, notably regression of pulmonary artery pressure, normal growth, and lack of long-term chest complications.

Adolescent↗
PubMed1997

Medium term results of direct bronchial arterial revascularisation using IMA for single lung transplantation (SLT with direct revascularisation).

OBJECTIVE: To describe a technique of direct revascularisation of the bronchial artery using the left IMA and assess its medium term results in patients undergoing left single lung transplant (SLT). METHODS: Between March 1991 and September 1993, 22 patients who underwent direct bronchial revascularisation at the time of left SLT (20 pedicled IMA, one free IMA, and one direct anastomosis to the aorta) have been followed up for a minimum period of 1 year (mean 30 +/- 12 months). Their mean age was 47.8 +/- 9.6 and the original disease was emphysema in 19, lymphangioleiomyomatosis in two, and pulmonary fibrosis in one. The mean ischaemia time was 269.7 +/- 23.4 min. RESULTS: There was one early death (4.5%) and 3 patients were re-explored for bleeding. The actuarial survival at 1 and 3 years was 91 +/- 0.4% and 82.6 +/- 1%, respectively. Bronchial healing was excellent in all patients and angiographic studies showed patent vascular anastomosis in all 22 patients, with good run off in 20 and poor in two. One patient developed clinical obliterative bronchiolitis at 22 months (4.5%) during a period of follow up varying from 12 to 43 months (mean 30 S.D. 12). At last follow up the mean FEV1 was 1.4 +/- 0.4 and the mean FVC was 2.2 +/- 0.6. On average, each patient developed 1.5 +/- 0.6 infection episodes and 1 +/- 0.2 acute lung rejection. CONCLUSION: It is concluded that the medium term results of direct bronchial revascularisation are good. However the influence of this procedure on long term results needs further investigation.

Adult↗
PubMed1997

Early experience with single lung transplantation for emphysema with simultaneous volume reduction of the contralateral lung.

OBJECTIVE: Single lung transplantation (SLT) for emphysema has given satisfactory long term results in most patients. The mediastinal shift caused by the native emphysematous lung may require further surgical intervention in selected cases. METHODS: We report a technique of simultaneous SLT and volume reduction of the contralateral lung in 4 patients with end stage respiratory failure secondary to emphysema. There were two right and two left SLT, performed in two male and two female patients. Their mean age was 52.2 (S.D. 4) years (range between 41 and 57 years) and the ischaemia time averaged 255.6 (S.D. 16) min (range between 225 and 255 min). The volume of the contralateral lung was reduced using staples. The stapled lines were buttressed by the donors pericardium. RESULTS: Their were no operative related complications apart from air leak which settled spontaneously within 5 days postoperatively. Teh pre-operative FEVI showed a mean value of 0.57 (S.D. 0.1) L (17.2% (S.D. 2) of the predicted) which improved to 1.79 (S.D. 0.4) L (58.2% (S.D. 8) of the predicted) at last follow up (P < 0.005). Radiological examinations at 1 year showed central mediastinum with satisfactory respiratory function. CONCLUSION: We conclude that this technique can be performed for patients with emphysema without increase in the operative morbidity and with good early respiratory function. Further follow up is required to assess the long term results of this procedure.

Adult↗
PubMed1997

An evaluation of nebulized prostacyclin in patients with primary and secondary pulmonary hypertension.

AIMS: To investigate the response to inhaled prostacyclin in patients with primary and secondary pulmonary hypertension and to compare its effects to those of intravenous prostacyclin and inhaled nitric oxide. METHODS AND RESULTS: Twelve patients with pulmonary hypertension (seven primary and five secondary) were studied. All patients had a pulmonary artery balloon flotation catheter inserted into the proximal pulmonary artery and radial arterial line. Prostacyclin was nebulized with 81.min-1 of oxygen and administered in doses increasing from 15 to 50 ng.kg-1.min-1 via a facemask. Eight of these patients also received intravenous prostacyclin in doses of 1 to 5 ng.kg-1.min-1 and nitric oxide in doses of 10 to 100 ppm via a facemask. Haemodynamic measurements were taken during each treatment. In the 12 patients, nebulized prostacyclin produced a significant reduction in mean pulmonary artery pressure from 56 +/- 5 to 45 +/- 4 mmHg (P = 0.0001). The pulmonary vascular resistance decreased by 38% from 964 +/- 169 to 595 +/- 116 dyne.s-1.cm-5 (P = 0.0001). Direct comparison with inhaled nitric oxide and intravenous prostacyclin in eight patients demonstrated that nebulized prostacyclin produced a greater fall in mean pulmonary artery pressure than the other two agents without any significant effect on systemic arterial pressure. CONCLUSION: Nebulized prostacyclin appears to be more effective at reducing pulmonary artery pressure in patients with pulmonary hypertension when compared to intravenous prostacyclin and inhaled nitric oxide. This could have important clinical implications for the management of patients with pulmonary hypertensions.

Administration, Inhalation↗
PubMed1996

Alternative technique for assessment and repair of the mitral valve.

Valve repair is preferred over replacement in the management of mitral regurgitation when technically possible. Central to the achievement of a durable result is precise assessment of the anatomic abnormality present before repair, as well as accurate intraoperative evaluation of the adequacy of repair accomplished. Cardioplegic techniques commonly employed permit inspection of the valve in a flaccid, arrested state, which may not accurately reflect its function in the contractile heart. The repair can be tested under normal loading conditions only after separation from cardiopulmonary bypass. An alternative technique of myocardial management employing mild hypothermia, continuous aortic root perfusion, and intermittent fibrillation is described that provides an opportunity to directly examine the valve under physiologic conditions before, during, and after completion of the repair.

Cardiac Surgical Procedures↗
PubMed1995

Reoperative aortic valve operation after homograft root replacement: surgical options and results.

The surgical options available and the associated operative risks for repeat aortic valve replacement after free-standing homograft root replacement with reimplantation of the coronary arteries are as yet undefined. We therefore reviewed our experience with repeat aortic valve replacement between January 1976 and July 1994 and identified 22 such procedures performed on 21 patients after homograft or autograft root replacement. Reoperation was indicated for structural deterioration in 16 and for bacterial endocarditis in 6 patients. Associated procedures were undertaken in 5 patients, and 4 procedures were performed emergently. Significant calcification of the homograft wall was noted in over half of all patients. There were no coronary ostial complications. In 13 patients new valves were inserted within the previous root: 9 mechanical valves and 4 subcoronary homografts. In 9 patients the root was re-replaced. The mean cross-clamp time was 85 (+/- 20) minutes and mean cardiopulmonary bypass time was 123 (+/- 32) minutes. There were no early deaths and 5 late deaths. Two patients required reoperation for bleeding and 2 experienced low cardiac output syndromes postoperatively. Univariate analysis failed to identify any variables predictive of outcome. We conclude that repeat aortic valve replacement after homograft root replacement, even in the presence of significant calcification, can be undertaken with an acceptable operative risk and should not be delayed until irreversible ventricular dysfunction has occurred. The same options available at initial valve replacement may be employed at reoperation, although extensive calcification mandates repeat root replacement.

Adolescent↗
PubMed1995

Early experience with the Toronto stentless porcine valve.

Stentless porcine valves in the aortic position offer many theoretic advantages, but their clinical performance has not been adequately defined. We evaluated the clinical and echocardiographic results of 103 patients who had aortic valve replacement with the Toronto stentless porcine valve over a 2-year period. There were 67 men with a mean age of 68 years. The predominant native valve lesion was aortic stenosis (64%), and 4 patients had prosthetic valve dysfunction. Forty-two patients had concomitant procedures. The 30-day mortality rate was 3.3% (n = 2) for isolated valve replacement and 5.8% (n = 6) for the series. The sole determinant of early death was poor left ventricular function. There were three late deaths due to non-valve-related complications over a median follow-up of 11.87 months. In addition, prosthetic valve endocarditis developed in 1 patient, necessitating a homograft valve replacement at 6 weeks. Doppler echocardiography performed at 3 to 6 months showed low peak and mean transvalvular gradients, with no substantial change at 1 year. None of the patients showed signs of clinically significant aortic regurgitation, although echocardiography demonstrated trivial or mild regurgitation in 12 patients at discharge or early follow-up, which was less marked or absent at 1 year. We conclude that the Toronto stentless porcine valve appears to offer promising early results.

Adult↗
PubMed1995

Fourteen-year experience with homovital homografts for aortic valve replacement.

Two hundred seventy-five unprocessed, viable homograft ("homovital") aortic valves were used for aortic valve replacement in patients aged 1.5 to 79 years (mean 45.8 +/- 19 years) with maximum follow-up of a 14-year period (mean 4.8 years). Ninety-two percent (252 patients) had New York Heart Association class III or IV functional status before operation and 25 underwent emergency operation. Valves were harvested under sterile conditions and kept in nutrient medium 199. Freehand (subcoronary) technique was used in 147 patients and freestanding root replacement was used in 128. Cumulative survival rates for the whole group were 92% +/- 2% at 5 years and 85% +/- 3% at 10 years, as compared with 96% +/- 2% and 94% +/- 4%, respectively, for the 98 patients who underwent isolated root replacement. Multivariate analysis determined that root replacement with associated procedures and operation for prosthetic endocarditis were risk factors for death, whereas previous xenograft valve, operation for endocarditis, and operation for aortic regurgitation were risk factors for reoperation. Actuarial rates for freedom from degenerative valve failure diagnosed at operation, by postmortem examination, or by routine echocardiography were 94% +/- 2% at 5 years and 89% +/- 3% at 10 years. Recipient age younger than 30 years and previous xenograft valve were risk factors for late degeneration. We conclude that homovital valves demonstrate good durability, particularly in patients older than 30 years, who had a 10-year freedom from degeneration rate of 97%.

Adolescent↗