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J B Orens

Publications and source records attributed to J B Orens.

At least 19 recordsLinked to original sources
PubMed2006

Thoracic organ transplantation in the United States, 1995-2004.

This article reviews trends in thoracic organ transplantation based on OPTN/SRTR data from 1995 to 2004. The number of active waiting list patients for heart transplants continues to decline, primarily because there are fewer patients with coronary artery disease listed for transplantation. Waiting times for heart transplantation have decreased, and waiting list deaths also have declined, from 259 per 1000 patient-years at risk in 1995 to 156 in 2004. Fewer heart transplants were performed in 2004 than in 1995, but adjusted patient survival increased to 88% at 1 year and 73% at 5 years. Emphysema, idiopathic pulmonary fibrosis and cystic fibrosis were the most common indications among lung transplant recipients in 2004. Waiting time for lung transplantation decreased between 1999 and 2004. Waiting list mortality decreased to 134 per 1000 patient-years at risk in 2004. One-year survival following transplantation has improved significantly in the past decade. The number of combined heart-lung transplants performed in the United States remains low, with only 39 performed in 2004. Overall unadjusted survival, at 58% at 1 year and 40% at 5 years, is lower among heart-lung recipients than among either heart or lung recipients alone.

Adolescent↗
PubMed2004

Lung transplant outcomes: a review of survival, graft function, physiology, health-related quality of life and cost-effectiveness.

The success of lung transplantation has improved over time as evidenced by better long-term survival and functional outcomes. Despite the success of this procedure, there are numerous problems and complications that may develop over the life of a lung transplant recipient. With proper monitoring and treatment, the frequency and severity of these problems can be decreased. However, significant improvement for the overall outcomes of lung transplantation will only occur when better methods exist to prevent or effectively treat chronic rejection.

Cost-Benefit Analysis↗
PubMed2001

Lung transplantation for primary and secondary pulmonary hypertension.

BACKGROUND: Single lung transplantation (SLT) and bilateral lung transplantation (BLT) are routinely performed in patients with primary pulmonary hypertension (PPH) and secondary pulmonary hypertension (SPH). It is unclear which procedure is preferable. We reviewed our experience with lung transplants for PPH and SPH to determine if any advantage exists with SLT or BLT for either PPH or SPH. METHODS: We reviewed the outcomes of all lung transplants performed for PPH or SPH for 4.5 years (July 1995 to January 2000). Survival was reported by the Kaplan-Meier method, and log rank analysis was used to determine significance. Statistical analyses of clinical data were performed using analysis of variance and chi2 analysis. RESULTS: A total of 57 recipients met criteria for pulmonary hypertension with a mean pulmonary artery pressure of greater than or equal to 30 mm Hg. There were 15 patients with PPH and 40 patients with SPH. There were 6 patients who had SLTs and 9 patients who had BLTs in the PPH group; and there were 9 patients who had SLTs and 21 patients who had BLTs in the SPH group. We found a survival advantage for PPH patients who underwent BLTs at all time points up to 4 years (100% vs 67%; p < or = 0.02). There was no clear advantage to SLTs or BLTs for SPH. At 4 years there was a trend toward improved survival with SLTs (91% vs 75%) in SPH patients with a mean pulmonary artery pressure less than or equal to 40 mm Hg (p < or = 0.11) with equivalent survival (80%) in patients with a mean pulmonary artery pressure greater than or equal to 40 mm Hg. There was also a trend toward improved survival in patients with a mean pulmonary artery pressure greater than or equal to 40 mm Hg (PPH and SPH) with BLTs (88% vs 62%; p = 0.19). The incidence of rejection, infection, and other complications was comparable between SLTs and BLTs in each group. CONCLUSIONS: We believe that BLT is the procedure of choice for PPH. The procedure of choice is less clear for SPH. Patients with SPH and a mean pulmonary artery pressure greater than 40 mm Hg may benefit from a BLT and those with a mean pulmonary artery pressure less than or equal to 40 mm Hg may do better with an SLT; however, no clear advantage is seen.

Adult↗
PubMed2001

Patterns and significance of exhaled-breath biomarkers in lung transplant recipients with acute allograft rejection.

BACKGROUND: Obliterative bronchiolitis (OB) remains one of the leading causes of death in lung transplant recipients after 2 years, and acute rejection (AR) of lung allograft is a major risk factor for OB. Treatment of AR may reduce the incidence of OB, although diagnosis of AR often requires bronchoscopic lung biopsy. In this study, we evaluated the utility of exhaled-breath biomarkers for the non-invasive diagnosis of AR. METHODS: We obtained breath samples from 44 consecutive lung transplant recipients who attended ambulatory follow-up visits for the Johns Hopkins Lung Transplant Program. Bronchoscopy within 7 days of their breath samples showed histopathology in 21 of these patients, and we included them in our analysis. We measured hydrocarbon markers of pro-oxidant events (ethane and 1-pentane), isoprene, acetone, and sulfur-containing compounds (hydrogen sulfide and carbonyl sulfide) in exhaled breath and compared their levels to the lung histopathology, graded as stable (non-rejection) or AR. None of the study subjects were diagnosed with OB or infection at the time of the clinical bronchoscopy. RESULTS: We found no significant difference in exhaled levels of hydrocarbons, acetone, or hydrogen sulfide between the stable and AR groups. However, we did find significant increase in exhaled carbonyl sulfide (COS) levels in AR subjects compared with stable subjects. We also observed a trend in 7 of 8 patients who had serial sets of breath and histopathology data that supported a role for COS as a breath biomarker of AR. CONCLUSIONS: This study demonstrated elevations in exhaled COS levels in subjects with AR compared with stable subjects, suggesting a diagnostic role for this non-invasive biomarker. Further exploration of breath analysis in lung transplant recipients is warranted to complement fiberoptic bronchoscopy and obviate the need for this procedure in some patients.

Acetone↗
PubMed2001

Induction therapy in lung transplantation: a prospective, controlled clinical trial comparing OKT3, anti-thymocyte globulin, and daclizumab.

BACKGROUND: Because acute rejection is associated with inferior outcomes in lung transplantation, we have routinely employed OKT3, anti-thymocyte globulin (ATG), or daclizumab as adjuncts to reduce rejection. METHOD: We performed a 4-year prospective, controlled clinical trial of these 3 therapies to determine differences in post-operative infection, rejection, survival, and bronchiolitis obliterans syndrome (BOS). Eighty-seven consecutive lung transplant patients received OKT3 (n = 30), ATG (n = 34), and daclizumab (n = 23) as induction agents. The groups had similar demographics and immunosuppression protocols differing only in induction agents used. RESULTS: No differences were observed in immediate post-operative outcomes such as length of hospitalization, ICU stay, or time on ventilators. Twelve months post-transplant, OKT3 had more infections per patient than the other agents, a difference that only became significant 2 months post-operatively (p = 0.009). The most common infection was bacterial and OKT3 had more bacterial infections than any other agent. Daclizumab had more patients remain infection free in the first year (p = 0.02), having no fungal infections and a low rate of viral infections. No patient receiving daclizumab developed drug specific side-effects. Only those patients with episodes of acute rejection developed BOS. There were no significant differences in the freedom from acute rejection or BOS between the groups. The 2-year survival for the entire cohort was 68%, with no differences observed in patient survival. CONCLUSIONS: This study again reveals the importance of acute rejection in the subsequent development of BOS. Although daclizumab offers a low risk of post-transplant infection and drug specific side-effects, no drug is superior in delaying rejection or BOS or in prolonging long-term survival.

Adult↗
PubMed2001

Lung transplantation for pulmonary hypertension.

Although lung transplantation is a viable option for patients with end-stage pulmonary hypertension, it is associated with numerous problems including infection, rejection, and limited long-term survival. Because of these limitations, transplantation should only be considered for patients who are failing maximal medical therapy. Treatment options for patients with pulmonary hypertension that may serve to prolong or obviate the need for transplantation include anticoagulation with warfarin, diuretics, and vasodilators such as calcium channel blockers or continuous intravenous epoprostenol (prostacyclin). The response to medical therapy should be assessed at regular intervals by evaluating exercise tolerance and hemodynamic parameters. Because waiting periods for transplantation now exceed 1.5 to 2 years in the United States, and the response to medications is unpredictable, referral for transplantation should occur when patients become symptomatic. Those who are responding well to medical therapy should be removed from the active transplant waiting list, whereas those who fail therapy should go on to transplant. Utilizing medical therapy and transplantation as complementary treatments will achieve the best potential to improve quality of life and prolong survival.

Journal Article↗
PubMed2000

Primary posttransplant lymphoproliferative disorder of the gallbladder in a lung transplant patient presenting with acute cholecystitis.

BACKGROUND: Acute cholecystitis in an immunocompromised host is potentially devastating. Posttransplant lymphoproliferative disorder (PTLD) is a well described complication of immunosuppressive therapy used after solid organ transplantation; however, isolated involvement of the gallbladder has not been described. METHODS: Case report format is used. RESULTS: We report a case of PTLD isolated to the gallbladder, as well as histological evidence of acute cholecystitis, in a patient who presented with signs and symptoms of acute cholecystitis 1 year after single lung transplant. CONCLUSIONS: PTLD can occur in the setting of acute cholecystitis and may be missed if careful pathological examination is not undertaken.

Acute Disease↗
PubMed2000

Lung transplantation from dialysis dependent donors.

Lung transplantation from a donor with chronic renal failure has never been reported. This paper reports our successful experience with 2 transplants from donors with end-stage renal disease who were on chronic hemodialysis, and reviews the relevant literature on the effects of renal failure on pulmonary function and on the use of marginal donors.

Adult↗
PubMed2000

High dose rate brachytherapy to prevent recurrent benign hyperplasia in lung transplant bronchi: theoretical and clinical considerations.

BACKGROUND: Significant anastomotic stenosis and malacia is reported to affect 7% to 15% of lung transplant recipients. Laser debridement, dilation and stenting can be used effectively to treat the majority of these patients. However, persistent, as well as reactive hyperplastic tissue reaction, will occur in some of these patients, requiring multiple bronchoscopic interventions. The experience of 2 patients who received intraluminal brachytherapy irradiation to prevent recurrence of hyperplastic tissue causing airway obstruction is reported. Both had failed multiple attempts of local control, including wall stent, laser ablation and balloon dilation. They suffered from shortness of breath and progressive decrease in quality of life because of airway obstruction. METHODS: Two patients received intraluminal irradiation immediately following removal of severe post-lung transplant obstruction. Both patients developed airway obstruction 3 to 4 months after left lung transplantation. High Dose Rate (HDR) brachytherapy (192Ir). Afterloader was used to treat Patient 1 on two occasions. Patient 2 required a single treatment. The radiation dose of 3Gy/fraction was calculated at 1 cm from the catheter for all applications. RESULTS: Follow up for both patients included bronchoscopy at 3 weeks, 3 months and 6 months after radiation therapy. Follow up for Patient 1 is 7 months, and patient 2 is 6 months. Each patient had an initial complete response after radiation. There were no treatment-related complications, and both patients experienced significant improvement in respiratory function. CONCLUSIONS: Symptomatic benign airway obstruction from hyperplastic tissue in the bronchus after lung transplantation can be successfully treated with intraluminal radiation therapy. Patients who develop recurrent benign granulation tissue after stent and laser therapy may be considered for this type of treatment.

Aged↗
PubMed2000

Three-dimensional CT-guided bronchoscopy with a real-time electromagnetic position sensor: a comparison of two image registration methods.

STUDY OBJECTIVES: To compare two different image registration methods for accurately displaying the position of a flexible bronchoscope on a previously acquired three-dimensional CT scan during bronchoscopy. SETTING: Bronchoscopy suite of a university hospital. PATIENTS: Fifteen adult patients scheduled for nonemergent bronchoscopy. METHODS: A miniature electromagnetic position sensor was placed at the tip of a flexible bronchoscope. Previously acquired three-dimensional CT scans were registered with the patient in the bronchoscopy suite. Registration method 1 used multiple skin fiducial markers. Registration method 2 used the inner surface of the trachea itself for registration. Method 1 was objectively assessed by measuring the error distance between the real skin marker position and the computer display position. Methods 1 and 2 were subjectively assessed by the bronchoscopist correlating visual bronchoscopic anatomic location with the computer display position on the CT image. RESULTS: The error distance (+/- SD) from known points for registration method 1 was 5.6 +/- 2.7 mm. Objective error distances were not measured for method 2 because no accurate placement of the bronchoscope sensor could be correlated with CT position. Subjectively, method 2 was judged more accurate than method 1 when compared with the fiberoptic view of the airways through the bronchoscope. Additionally, method 2 had the advantage of not requiring placement of fiducial markers before the CT scan. Respiratory motion contributed an error of 3.6 +/- 2.6 mm, which was partially compensated for by a second tracking sensor placed on the patient's chest. CONCLUSION: Image registration method 2 of surface fitting the trachea rather than method 1 of fiducial markers was subjectively judged to be superior for registering the position of a flexible bronchoscope during bronchoscopy. Method 2 was also more practical inasmuch as no special CT scanning technique was required before bronchoscopy.

Biopsy↗
PubMed2000

Lung transplantation and systemic sclerosis.

We performed lung transplantation in nine patients with Scleroderma related lung disease. Patient characteristics included: 7 (78%) females, 6 (67%) with limited and 3 (33%) with diffuse Scleroderma. Pulmonary fibrosis was present in 7 (78%) and pulmonary hypertension in 4 (44%). All patients were carefully screened by the Johns Hopkins and University of Maryland Scleroderma Center and only referred for transplantation when concomitant renal insufficiency (creatinine clearance < or = 50 ml/min), aspiration, and skin brakdown were excluded. When compared to a similar group of transplant patients with nonscleroderma lung disease (primary pulmonary fibrosis), there was no significant difference in post-transplant survival at four years (76.2 +/- 0.15% vs. 69.2% +/- 0.12%), mean annual incidence rate for acute rejection (0.14 +/- 0.14 vs. 0.47 +/- 0.13) and infection (viral 0.17 +/- 0.17 vs. 0.29 +/- 0.11) (bacterial 0.17 +/- 0.17 vs. 1.4 +/- 0.4) (fungal 0.99 +/- 0.69 vs. 0.36 +/- 0.16) or serum creatinine (1.55 +/- 0.34 mg/dl vs. 1.15 +/- 0.09 mg/dl). We conclude that lung transplantation is viable option for carefully selected patients with scleroderma related lung disease.

Contraindications↗
PubMed1999

Lung transplantation in a Jehovah's Witness.

Patients of the Jehovah's Witness faith generally do not accept transfusions of blood or blood products but some will accept cadaveric organs for transplantation. We report a left single lung transplantation in a 48-year-old Hispanic female with idiopathic pulmonary fibrosis and secondary pulmonary hypertension. We believe this is the first reported case of lung transplantation in a Jehovah's Witness.

Christianity↗
PubMed1999

Respiratory response during arm elevation in isolated diaphragm weakness.

Upper extremity exercise is associated with a significant metabolic and ventilatory cost that is particularly evident in patients with severe chronic airflow obstruction. In these patients abnormal ventilatory muscle recruitment has been hypothesized to relate to impaired diaphragm function resulting from hyperinflation. Similar data have never been reported in patients with isolated diaphragm weakness but without airflow obstruction or hyperinflation, a group that would ideally define the role of diaphragm function during arm elevation (AE). We prospectively studied 15 patients with isolated diaphragm weakness of varying severity (Pdi(sniff), 31.74 +/- 3.75 cm H(2)O) as contrasted with eight normal subjects (Pdi(sniff), 111. 77 +/- 13.35 cm H(2)O) of similar age. Patients with diaphragm weakness demonstrated significant lung volume restriction with normal DL(CO)/VA. There was no difference in resting oxygen consumption (V O(2)), carbon dioxide production (V CO(2)), minute ventilation (V E), and tidal volume (VT) between the two groups; however, a borderline difference in resting breathing frequency (f(b)) (p = 0.056) was evident. Both groups demonstrated a rise in V O(2), V CO(2), and V E during 2 min of AE anteriorly. Normal subjects demonstrated a statistically significant rise in VT but a statistically insignificant rise in f(b) during AE. In contrast, patients with diaphragm weakness demonstrated a statistically significant rise in f(b) during AE but a statistically insignificant rise in VT. In patients the observed rise in VT directly correlated with baseline Pdi(sniff) (r = 0.59, p = 0.02) and Pdi(max) (r = 0.81, p = 0.002). Both groups demonstrated a rise in Pdi during AE. The rise in Pdi during AE directly correlated to Pdi(sniff) in the patients (r = 0.69, p = 0.004). Observed end-expiratory Ppl rose during arm elevation in both the patient group and in the normal control group, but no evidence of a differential response to AE was found. In those patients with greater diaphragm weakness (Pdi(sniff) < 30 cm H(2)O), abnormal respiratory muscle function (lesser rise in Pdi) and a lesser increase in VT during AE were more evident. These data highlight the importance of diaphragm function in determining the metabolic and respiratory muscle response to arm elevation.

Adult↗
PubMed1998

Dysfunctional voltage-gated K+ channels in pulmonary artery smooth muscle cells of patients with primary pulmonary hypertension.

BACKGROUND: Primary pulmonary hypertension (PPH) is a rare disease of unknown cause. Although PPH and secondary pulmonary hypertension (SPH) share many clinical and pathological characteristics, their origins may be disparate. In pulmonary artery smooth muscle cells (PASMCs), the activity of voltage-gated K+ (KV) channels governs membrane potential (Em) and regulates cytosolic free Ca2+ concentration ([Ca2+]cyt). A rise in [Ca2+]cyt is a trigger of vasoconstriction and a stimulus of smooth muscle proliferation. METHODS AND RESULTS: Fluorescence microscopy and patch clamp techniques were used to measure [Ca2+]cyt, Em, and KV currents in PASMCs. Mean pulmonary arterial pressures were comparable (46+/-4 and 53+/-4 mm Hg; P=0.30) in SPH and PPH patients. However, PPH-PASMCs had a higher resting [Ca2+]cyt than cells from patients with SPH and nonpulmonary hypertension disease. Consistently, PPH-PASMCs had a more depolarized Em than SPH-PASMCs. Furthermore, KV currents were significantly diminished in PPH-PASMCs. Because of the dysfunctional KV channels, the response of [Ca2+]cyt to the KV channel blocker 4-aminopyridine was significantly attenuated in PPH-PASMCs, whereas the response to 60 mmol/L K+ was comparable to that in SPH-PASMCs. CONCLUSIONS: These results indicate that KV channel function in PPH-PASMCs is inhibited compared with SPH-PASMCs. The resulting membrane depolarization and increase in [Ca2+]cyt lead to pulmonary vasoconstriction and PASMC proliferation. Our data suggest that defects in PASMC KV channels in PPH patients may be a unique mechanism involved in initiating and maintaining pulmonary vasoconstriction and appear to play a role in the pathogenesis of PPH.

Adult↗
PubMed1998

Acute effects of bilateral lung volume reduction surgery on lung and chest wall mechanical properties.

STUDY OBJECTIVES: To characterize acute changes in the dynamic, passive mechanical properties of the lungs and chest wall, elastance (E) and resistance (R), caused by lung volume reduction surgery (LVRS). DESIGN: Prospective data collection. PATIENTS: Nine anesthetized/paralyzed patients with severe emphysema. INTERVENTIONS: Bilateral LVRS. MEASUREMENTS AND RESULTS: From measurements of airway and esophageal pressures and flow during mechanical ventilation throughout the physiologic range of breathing frequency (f) and tidal volume (VT), E and R of the total respiratory system (Ers and Rrs), lungs (EL and RL), and chest wall (Ecw and Rcw) immediately before and after LVRS were calculated. After surgery, Ers, EL, Rrs, and RL were all greatly increased at each combination off and VT (p<0.05). Ecw and Rcw showed no consistent changes (p>0.05). The increases in EL were greatest in those patients with the lowest residual volumes, highest FEV1 values, and highest maximum voluntary ventilations measured 3 months preoperatively (p<0.05); the increases in RL were greatest in those patients with the lowest preoperative residual volumes (p<0.05). The largest increases in RL were in those patients with the largest decreases in residual volume and total lung capacity, measured 3 months postoperatively, caused by LVRS (p<0.05). CONCLUSION: Acute effects of LVRS are large increases in lung elastic tension and resistance; these increases need to be considered in immediate postoperative care, and can be predicted roughly from results of preoperative pulmonary function tests.

Aged↗
PubMed1998

The influence of continuous intravenous prostacyclin therapy for primary pulmonary hypertension on the timing and outcome of transplantation.

BACKGROUND: Primary pulmonary hypertension (PPH) is a progressive disease with a median survival of less than 3 years from diagnosis. Medical management has typically consisted of anticoagulation and oral calcium channel blocking agents, whereas lung transplantation (LT) has been reserved for patients who are unresponsive to medical therapy. Continuous intravenous prostacyclin was introduced for patients who did not respond to calcium channel blockers and who would have required LT. We reviewed our experience with prostacyclin in LT candidates to study its effects on the timing and outcome of LT. METHODS: We retrospectively reviewed the clinic and hospital records of patients with PPH who were both treated with prostacyclin and evaluated for LT. Additional information was obtained from the pulmonary vascular disease and lung transplantation databases. RESULTS: A total of 42 patients were identified who received prostacyclin for the treatment of PPH and were evaluated for LT. Thirty-seven patients were accepted as LT candidates, 22 at The University of Maryland Medical Center (UMMC), 15 at other LT programs. Overall, 70% (27/37) of LT candidates were removed from the LT waiting list or had listing for LT deferred because of clinical improvement. In patients listed for LT before initiation of prostacyclin therapy, 55% (12/22) were removed from the active waiting list for 27.2+/-17 months (range 8 to 60), and 92% (11/12) remain on the inactive status. In patients who received prostacyclin before listing for LT, listing for LT was deferred in 94% (14/15) for 17.4+/-9 months (range 6 to 33 months) because of clinical stability or improvement. In all, 93% of patients (39/42) experienced an improvement in 1 or more New York Heart Association functional class. The hemodynamic profiles of the eight patients removed from the active waiting list at UMMC demonstrated increases of 55%+/-18% in cardiac output, and decreases of 14.3%+/-4.9% in mean pulmonary artery pressure and 36%+/-8.3% in total pulmonary resistance (p < 0.05). The 1-year survival rate for LT after prostacyclin therapy was 88% (7/8) at UMMC and 60% (3/5) at the other centers. CONCLUSION: We conclude that prostacyclin therapy is an effective means of delaying, possibly indefinitely, the need for LT in patients with PPH and that excellent results can be obtained when LT is performed after prostacyclin therapy. Consideration should be given to initiating prostacyclin therapy in all patients whose conditions do not respond to conventional therapy before proceeding with transplantation.

Adult↗