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S Taghavi

Publications and source records attributed to S Taghavi.

At least 19 recordsLinked to original sources
PubMed2004

Size-reduced lung transplantation: an advanced operative strategy to alleviate donor organ shortage.

BACKGROUND: The increasing need for donor lungs, especially for small and pediatric recipients, has not been matched by an adequate supply. This disparity has stimulated the development of new operative techniques, which allow downsizing of larger lungs for use in smaller recipients, thus potentially expanding the donor pool. This approach has recently gained more widespread use, especially for highly urgent recipients; however, is still not considered a standard procedure. PATIENTS AND METHODS: All primary size-reduced lung transplants performed from January 2001 to December 2003 were retrospectively reviewed. Downsizing was achieved by either split-lung transplantation, lobar transplantation, or by means of a peripheral wedge resection. Waiting list time, perioperative complications, and outcomes of those patients were compared to patients undergoing primary standard single or double lung transplantation during the observation period. RESULTS: Among 163 primary lung transplantations 51 (31.3%) were size-reduced procedures. Size reduction was achieved by lobar transplantation (n = 18), split-lung transplantation (n = 2), or peripheral segmental resection (n = 31). There was a slightly decreased waiting time among the size-reduced group (74 +/- 72 vs 98 +/- 90 days, P = .13). No statistically significant difference between the size-reduced and the standard lung transplantation group was evident with regard to the rate of bronchial healing problems (n = 3/9; P = .62) or the rate of revision due to postoperative bleeding (n = 6/15; P = .77). No other major thoracic surgical complications were observed. The 3-month survival rate was 86.3% in the size-reduced 92.0% in the standard group (P = .09). CONCLUSION: Size-reduced lung transplantations, including split-lung transplantation, lobar transplantation, and peripheral segmental resection, may be considered reliable procedures that provide results comparable to standard lung transplantation. It allows the use of oversized grafts for small and pediatric recipients and the use of single lobes if localized pathologies exist, thus enlarging the donor pool and potentially helping to reduce waiting times and waiting list mortality.

Cadaver↗
PubMed2003

Rapamycin as rescue therapy in a patient supported by biventricular assist device to heart transplantation with consecutive ongoing rejection.

Rapamycin is a new immunosuppressive agent that has been shown to be effective in acute heart allograft rejection. This case documents a patient suffering from cardiac sarcoidosis who was bridged to transplantation for 90 days with ongoing rejection after allograft implantation. Rejection did not abate despite treatment with antithymocyte globulin (ATG), FK506, a mycophenolate switch and courses of multiple apheresis. Initiation of rapamycin treatment resulted in a rapid resolution of cardiac rejection and reduction of concomitant immunosuppressive agents with few side-effects. Most notably was the reduction of panel reactive antibodies within a few weeks after the rapamycin initiation. This case illustrates that the utilization of rapamycin ceased ongoing rejection in a patient with a clear hyperimmune state despite prior extensive utilization of a variety of immunosuppressive strategies after heart transplantation.

Adult↗
PubMed2002

Activation-induced T cell death, and aberrant T cell activation via TNFR1 and CD95-CD95 ligand pathway in stable cardiac transplant recipients.

Specific blockade by antibodies (Abs) utilized in induction therapy may cause activation-induced cell death (AICD) in lymphocytes of transplant recipients, preactivated via CD95 and tumour necrosis factor-alpha receptor type 1 (TNFR1), and reduce allograft rejection frequency. Amongst 618 heart transplant (HTX) patients receiving antithymocytes globulin (ATG) therapy, 14 recipients with IVUS-verified freedom of transplant vasculopathy were studied. The control group contained 14 patients awaiting transplantation, classified by the New York Hearth Association heart failure as class IV. From 618 HTX patients 89% were free of rejection grade ISHLT > or =2-3 within 3-month post transplantation and 86% after one year. The death inducing receptors (DIR) such as CD95, CD95L and soluble TNFR1 were significantly increased in HTX recipients versus controls, as demonstrated by FACS, immunoblotting or ELISA (P < 0.001). The presence of increased DIR and in vivo apoptosis in HTX recipients, indicated by annexin-V binding, was further confirmed by the presence of high concentration of histones in the sera of patients. ATG, anti-IL-2R and OKT-3 Abs inhibited cell proliferation in a dose-dependent manner. The induction of apoptosis and/or necrosis was demonstrated in cells cultured with these Abs by annexin-V and 7-aminoactinomycin staining, respectively. Our findings demonstrate that T cells from HTX recipients express high level of CD95, CD95L and soluble TNFR1, and undergo apoptosis and AICD. These cells recognizing donor alloantigens may be selectively eliminated in vivo, and should be responsible for the observed immunological unresponsiveness, indicated by low rejection rates in our patient cohort treated by conventional triple therapy.

Adult↗
PubMed2001

Impact of cardiac transplantation on molecular pathology of ET-1, VEGF-C, and mitochondrial metabolism and morphology in dilated versus ischemic cardiomyopathic patients.

Little is known about the long-term impact of cardiac transplantation on activity and modifications of endothelin (ET)-1 system, vascular endothelial growth factor (VEGF), and mitochondrial metabolism and morphology in patients with ischemic cardiomyopathy (ICM) versus dilated cardiomyopathy (DCM). Messenger RNA (mRNA) expression levels of ET-1, endothelin converting enzyme (ECE)-1, VEGF-C, carnitine palmitoyltransferase (CPT)-1, and carnitine acetyltransferase (CARAT), as well as the number of normal, edematous, and degenerated mitochondria were assessed in left ventricular biopsies of 21 patients with DCM and 20 with ICM (New York Heart Association class III-IV) before and up to 3 months after cardiac transplantation. Cardiac samples of donated, nonfailing hearts served as controls (n=10). In cardiac biopsies of both ICM and DCM patients, ET-1, VEGF-C, CPT-1, and CARAT mRNA were up-regulated, whereas ECE-1 mRNA was down-regulated (P<0.05). Degenerated mitochondria had the highest number in both groups, followed by normal and edematous mitochondria. After cardiac transplantation, in ICM patients impaired gene expression levels decreased to, or below, normal levels, and the number of normal mitochondria increased (P<0.05). In implanted hearts of DCM patients, however, up-regulated ET-1 transcript levels persisted and the number of normal mitochondria decreased, whereas the number of degenerated mitochondria increased (P<0.05), and edematous mitochondria remained unchanged in number. These results show that cardiac transplantation corrects the impaired hemodynamic and echocardiographic parameters in both groups, whereas in DCM, the molecular pathology of ET-1 system and mitochondria persists. Therefore, it is more likely that these changes are the cause rather than a consequence of DCM.

Adult↗
PubMed2001

Survival benefit of the implantable cardioverter-defibrillator in patients on the waiting list for cardiac transplantation.

BACKGROUND: The implantable cardioverter-defibrillator (ICD) effectively reduces sudden cardiac death in patients with severe LV dysfunction. Effect of ICD therapy on total mortality in patients on the waiting list for cardiac transplantation is still uncertain. METHODS AND RESULTS: We retrospectively analyzed 854 unselected consecutive patients (ICD therapy, n=102; 11.9%) on the waiting list for cardiac transplantation between January 1992 and March 2000. Actuarial 12-month total mortality rate on the waiting list was 24.2%; sudden cardiac death was the predominant mode of death (66.7% of total deaths). Kaplan-Meier analysis revealed improved survival for ICD (total mortality, 13.2%) compared with non-ICD (total mortality, 25.8%) patients (log rank, P=0.03). No event of sudden death occurred in ICD patients, whereas in non-ICD patients, 12-month sudden death rate was 20.1% (P=0.0001). Nonsudden death rates did not differ between ICD and non-ICD patients (P=0.16). A Cox proportional hazards model demonstrated that absence of an ICD was a powerful independent predictor of total mortality (P=0.02; relative risk, 2.22; 95% confidence interval, 1.16 to 4.17) and sudden cardiac death (P<0.0001; infinite relative risk) on the waiting list. CONCLUSIONS: ICD therapy, because it prevents sudden cardiac death, significantly improves survival on the waiting list for cardiac transplantation. The present study supports the use of ICDs as a bridge to transplantation in patients who are at risk of sudden cardiac death. Prospective randomized trials are needed to evaluate the potential benefit of prophylactic ICD therapy as a bridge to transplantation in all patients on cardiac transplant waiting lists.

Comorbidity↗
PubMed2001

Nickel-resistance-based minitransposons: new tools for genetic manipulation of environmental bacteria.

The ncc and nre nickel resistance determinants from Ralstonia eutropha-like strain 31A were used to construct mini-Tn5 transposons. Broad host expression of nickel resistance was observed for the nre minitransposons in members of the alpha, beta, and gamma subclasses of the Proteobacteria, while the ncc minitransposons expressed nickel resistance only in R. eutropha-like strains.

Conjugation, Genetic↗
PubMed2000

Pulmonary artery thromboendarterectomy: a comparison of two different postoperative treatment strategies.

UNLABELLED: Pulmonary artery thromboendarterectomy (PTE) is a potentially curative surgical procedure for chronic thromboembolic pulmonary hypertension. It is, nevertheless, associated with considerable mortality caused by postoperative complications, such as reperfusion pulmonary edema (RPE) (i.e., pulmonary infiltrates in regions distal to vessels subjected to endarterectomy) and right heart failure (RHF). However, there are no reports about the influence of different postoperative treatment strategies on complications and mortality. Therefore, we compared two different treatment strategies. In Group I (n = 33), positive inotropic catecholamines and vasodilators were avoided during termination of cardiopulmonary bypass (CPB) and thereafter, and mechanical ventilation was performed with low tidal volumes < 8 mL/kg, duration of inspiration:duration of expiration = 3:1, and peak inspiratory pressures < 18 cm H(2)O. In Group II (n = 14), positive inotropic catecholamines and vasodilators were regularly used for termination of CPB and thereafter, and ventilation was performed with high tidal volumes (10-15 mL/kg) and peak inspiratory pressures up to 50 cm H(2)O. Hemodynamics, the incidence of RPE and RHF, duration of ventilation, morbidity, and mortality were recorded. Cardiac index was comparable before surgery (2.11 +/- 0.09 vs 2.08 +/- 0.09 L. min(-1). m(-2)) and 20 min after CPB (2.26 +/- 0.09 vs 2.60 +/- 0.20 L. min(-1). m(-2)). RPE occurred in 6.1% (Group I) versus 14.3% (Group II), and RHF was observed in 9.1% (Group I) versus 21.4% (Group II). Mortality was 9.1% (Group I) versus 21.4% (Group II). Thus, the avoidance of positive inotropic catecholamines and vasodilators in combination with nonaggressive mechanical ventilation after PTE was associated with a low incidence of RPE, RHF, duration of ventilation, and mortality after PTE. IMPLICATIONS: The avoidance of positive inotropic catecholamines and vasodilators in combination with nonaggressive mechanical ventilation was associated with a low incidence of reperfusion pulmonary edema and/or right heart failure after pulmonary artery thromboendarterectomy.

Adult↗
PubMed2000

Lung transplantation today.

Lung transplantation has become an accepted surgical modality, and it is indicated in patients with a long-term benign pulmonary disease in stage when all the other therapeutic possibilities failed. Nowadays it presents a real possibility to significantly improve the quality of life. Success, (mainly in the last decade), establishing international professional centers, national coordinations, shifts transplantation towards the standard treatment procedures. The objective of the paper is to offer an overview of the international activities, trends and results in the area of lung transplantation. Authors present a review of the current situation based on their own experiences gained from the bilateral cooperation with Vienna Transplant Group. (Tab. 4, Fig. 4, Ref. 19.)

Humans↗
PubMed1999

T4 lung tumors with infiltration of the thoracic aorta: is an operation reasonable?

BACKGROUND: Only anecdotal reports about the results of combined resection of T4 lung tumors infiltrating the thoracic aorta exist. METHODS: Seven patients (mean age, 57.5 years; range, 43 to 78 years) underwent a resection of the infiltrated segment of the thoracic aorta together with a left pneumonectomy (n = 6) or left upper lobectomy (n = 1). Five tumors were primary non-small cell lung carcinomas (T4N2 in 3 patients, T4N1 in 2), one was a metastasis of breast cancer, and one was rhabdomyosarcoma. RESULTS: No patient died perioperatively. The 2 patients with rhabdomyosarcoma and metastasis of breast cancer died 2 and 7 months postoperatively. Of the 5 patients with bronchial carcinoma, 3 died after 17, 26, and 27 months as a result of distant metastasis. Two patients are alive after 14 and 50 months without evidence of disease recurrence. One-year, 2-year, and 4-year survival rates for patients with bronchial carcinoma were 100%, 75%, and 25%, respectively. CONCLUSIONS: Combined resection of the lung and thoracic aorta can be performed with low morbidity and mortality when offered to highly selected patients. Adequate local control of tumor can be achieved for N1 and single-level N2 non-small cell lung carcinomas, but not for tumors with other histologies.

Adenocarcinoma↗
PubMed1999

Initial experience with two sequential anterolateral thoracotomies for bilateral lung transplantation.

BACKGROUND: Bilateral transsternal thoracotomy (clamshell incision) is the standard approach used for bilateral sequential lung transplantation (BLTX). The morbidity of this large incision can be considerable. Two separate sequential anterolateral thoracotomies represent a less invasive approach. METHODS: The value of this approach was investigated in a prospective series of 13 consecutive patients with the underlying diagnosis of COPD or cystic fibrosis (group A). Results were compared to 8 consecutive patients with similar indications who had undergone BLTX via clamshell incision during the last year prior to this new technique (group B). RESULTS: No intraoperative complications occurred in either group. The difference between the cold ischemic time of the 1st and 2nd transplanted lung was comparable between the 2 groups (81 min+/-17 min in group A vs 79 min+/-14 min in group B, p = 0.783). Postoperative restriction was significantly less in the group operated through 2 separate thoracotomies, as proven by the vital capacity in the first spirometry performed during the 3rd postoperative week (VC group A 55%+/-16% predicted vs 41%+/-11% predicted in group B; p = 0.043). CONCLUSION: The bilateral sequential anterolateral thoracotomy represents a safe and less invasive approach for BLTX in patients with large chest volumes. It minimizes the operative trauma, improves postoperative functional recovery and prevents the potential spread of unilateral complications to the other pleural cavity.

Adult↗
PubMed1999

Bilateral lung transplantation via two sequential anterolateral thoracotomies.

OBJECTIVE: Bilateral anterior trans-sternal thoracotomy (clam shell incision) is the standard approach used for bilateral sequential lung transplantation (BLTX). The morbidity of this large incision can be considerable. Two separate sequential anterolateral thoractomies represent a less invasive approach. METHODS: The value of this approach was investigated in a prospective series of 22 consecutive patients who received BLTX between June 1997 and July 1998. Their underlying diseases were COPD (n = 16), cystic fibrosis (n = 4) and other (n = 2). All patients underwent BLTX through two anterolateral thoracotomies, without the use of cardiopulmonary bypass. The anterior mediastinum and the sternum with all the surrounding tissue were left completely intact. Twenty-one patients underwent spirometrical examination during the postoperative in-hospital stay. Follow-up is 7+/-4 months (range: 3 to 15). RESULTS: The only intraoperative complication was severe reperfusion edema of the first transplanted lung seen in one patient at the end of the operation, which required pneumonectomy during the same session. All other operations were uneventful. The difference between the cold ischemic time of the first and second transplanted lung was 83+/-17 min. Median intubation duration, ICU- and in-hospital-stay were 1.5, 5 and 20 days, respectively (ranges: 1 to 96, 2 to 96 and 15 to 96, respectively). One major perioperative complication occurred and was due to gross donor/recipient size mismatch: the patient required lobectomy of the consolidated right upper lobe 11 days after transplantation. In 19 patients (86.4%), this less extensive incision allowed early postoperative mobilization, which resulted in good ventilatory performance, with VC of 53+/-15 and FEV1 of 60+/-20% of the predicted, respectively, at the first spirometry, 3 weeks after the operation. Three months survival was 100%. CONCLUSION: The bilateral sequential anterolateral thoracotomy represents a safe and minimal invasive approach for BLTX compared with the clam shell incision. It minimizes the operative trauma, improves postoperative functional recovery and prevents the potential spread of unilateral complications to the other pleural cavity.

Adolescent↗
PubMed1999

Impact of different coverage techniques on incidence of postpneumonectomy stump fistula.

OBJECTIVE: Postpneumonectomy bronchial stump fistula (PBSF) is a serious complication with a reported incidence between 0 and 12%. The aim of this retrospective study was to investigate the effectiveness of different coverage techniques of the bronchial stump applied in a consecutive series of pneumonectomies in avoiding this particular problem. METHODS: Between 1/87 and 10/97, 129 patients (90 male, 39 female, mean age 57.8 years, range: 15-78 years) underwent pneumonectomy by one surgeon (W.K.). In 14 patients, additional resection procedures were performed (aorta n = 6, vena cava n = 5, thoracic wall n = 3). In all patients with malignancies (n = 123), mediastinal lymphadenectomy was routinely added to the procedure. Bronchial stump closure was performed by means of stapling devices in all patients. Coverage of the bronchial stump was performed with a generous pedicled pericardial flap and concomitant reconstruction of the pericardium with Vicryl mesh (n = 50), with a portion of the posterior pericardium (n = 16), with the azygos vein (n = 12), with surrounding mediastinal tissue (n = 25), with pleura (n = 16), or with intercostal muscle flap (n = 3); no coverage at all was performed in seven patients. In all patients with high risk for development of PBSF, i.e. patients who received any form of neoadjuvant therapy or had extended resections, the pericardial flap technique was used. RESULTS: Perioperative mortality was 5.4% (n = 7) and five patients (3.9%) experienced significant perioperative complications, with one of them directly related to the method of bronchial stump coverage (cardiac tamponade due to the use of a too small Vicryl mesh for reconstruction of the pericardium). Follow-up was 96.1% complete (five patients were lost to follow-up). Fourty-seven patients (36.4%) died late after operation (mean 19+/-13 months, median 17 months), mainly due to recurrence of their underlying malignant disease. PBSF occurred in one patient only (0.8%), 2 weeks after operation (coverage with pleura). No PBSF was seen in the long term follow-up period. CONCLUSION: Coverage of the bronchial stump contributes to a low incidence of PBSF. In view of the fact, that this serious complication was completely avoided in the pericardial flap group (used in patients with expected higher risk for PBSF), this particular technique seems to offer the best results.

Adolescent↗
PubMed1999

Transient left ventricular failure following bilateral lung transplantation for pulmonary hypertension.

BACKGROUND: Bilateral lung transplantation is an established therapy for end-stage pulmonary hypertension. Its early postoperative outcome may be biased by various complications resulting in unexpected deterioration of the patient in terms of hemodynamics and blood gases. METHODS: We have reviewed the early postoperative course of patients who underwent bilateral lung transplantation for pulmonary hypertension at our institution and analyzed all available data, especially hemodynamic measurements, echocardiographic documentation and therapeutical strategies, in those cases where cardiac dysfunction was found to be responsible for clinical deterioration. RESULTS: Three out of 20 lung transplant recipients operated for pulmonary hypertension experienced severe respiratory insufficiency accompanied by hemodynamic decompensation during the first days after surgery. Clinical and laboratory findings together with results of echocardiography and pulmonary artery catheterism helped establish the diagnosis of left ventricular failure. This proved to be transitory, but the response to therapy (inotropic drugs, afterload reduction and eventually prostaglandins) was very variable. Adequately treated, this complication did not preclude the outcome of transplantation by itself. CONCLUSION: Left ventricular failure is a possible complication after lung transplantation for pulmonary hypertension. Echocardiography and pulmonary artery catheterism may be useful adjuvant diagnostic tools, beside routine physical examination, chest X-ray, and laboratory analysis. Therapy of this complication must be adapted individually and may be complex.

Adult↗
PubMed1999

Comparison between mycophenolate mofetil- and azathioprine-based immunosuppressions in clinical lung transplantation.

BACKGROUND: The aim of the study was to assess the impact of mycophenolate mofetil (MMF) on the early phase after lung transplantation. PATIENTS AND METHODS: Thirty-eight consecutive patients between November 1994 and January 1997 were treated with cyclosporine, prednisolone, antithymocyte globuline induction therapy, and either MMF (n = 21) or azathioprine (Aza) (n = 17). Four patients from the MMF group and 2 patients from the Aza group were intubated and in the ICU prior to transplantation. Demographic data and primary diagnosis were comparable. MMF was administered at a dosage of 2 gm/day whereas Aza was initiated at 2 mg/kg/day and adapted by leukocyte count. Three-month survival and incidence of rejections and infections were compared. RESULTS: Six-month survival in the MMF group was 76% compared to 65% in the Aza group (n.s.). The mean number of acute rejection episodes in the MMF and Aza group were 0.29+/-0.10 and 1.53+/-0.29 (p<0.01) respectively. Transbronchial biopsy (TBB) results > or =grade 2 ISHLT were seen in 10% of MMF and in 43% of Aza-treated patients; completely free from rejection were 17 MMF and 3 Aza patients. The mean number of infections per patient in the MMF and Aza group were 1.57+/-0.29 and 2.29+/-0.40 respectively, bacterial (1.10 vs. 1.71), viral (0.35 vs. 0.33), and fungal (0.14 vs. 0.24) infections were the same in both groups. CONCLUSIONS: These data result suggest that mycophenolate mofetil therapy is more effective in preventing rejection episodes in patients early after lung transplantation than therapy with azathioprine. We therefore conclude that MMF is a safe and effective drug to optimize immunosuppressive therapy in the early phase after lung transplantation.

Adolescent↗