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Biomedical subjects

J K Kirklin

Publications and source records attributed to J K Kirklin.

At least 73 records · Page 4Linked to original sources
PubMed1995

Total lymphoid irradiation in the treatment of early or recurrent heart transplant rejection.

PURPOSE: Recurrent acute cardiac allograft rejection is an important cause of repeat hospitalization and a major mode of mortality, particularly during the 6 months immediately following transplant. Total lymphoid irradiation (TLI) has been shown experimentally to induce a state of partial tolerance when administered prior to transplantation. Anecdotal reports of clinical experience have also suggested efficacy of TLI in treatment of recurrent cardiac rejection. The purpose of this study is to evaluate the safety and efficacy of TLI for treatment of early or recurrent heart transplant rejection. MATERIALS AND METHODS: Between January 1990 and June 1992, 49 patients postallograft cardiac transplant were given courses of TLI for treatment of early or recurrent rejection after conventional therapy with Methylprednisolone, antithymocyte globulin, OKT3, and methotrexate. Two patients failed to complete their therapy and were not evaluated. Two other patients received a second TLI course, making a total of 49 courses delivered. Indications for TLI were early rejection (n = 5), recurrent rejection (n = 38), and recurrent rejection with vasculitis (n = 6). The dose goal of the TLI protocol was 8 Gy in 10 fractions given twice weekly. Three separate fields were used to encompass all major lymph node-bearing areas. The actual mean dose was 7 Gy (range 2.4-8.4 Gy), and the duration of treatment was 8 to 106 days. These variations were secondary to leukopenia or thrombocytopenia. RESULTS: The mean posttransplant follow-up is 15 +/- 1.2 months (maximum 27 months). Among patients initiating TLI within 1 month posttransplant (n = 15), the rejection frequency decreased from 1.83 episodes/patient/month pre-TLI to 0.13 episodes/patient/month post-TLI (p < 0.001). For those who began TLI 1-3 months after transplant (n = 21), rejection decreased from 1.43 to 0.10 episodes/patient/month (p < 0.001). When TLI was started more than 3 months posttransplant (n = 11), the pre-TLI and post-TLI rejection frequencies were 0.67 and 0.07/patient/month (p < 0.001), respectively. The reduced post-TLI rejection frequencies were maintained to 24 months. There was no increase in the frequency of infection after TLI, nor were there any deaths during or immediately following TLI. CONCLUSION: Total lymphoid irradiation is a safe and effective adjunct for prolonged control of early or recurrent cardiac rejection. Bone marrow suppression is transient in nearly all patients and is not associated with an increased incidence of infection. The long-term benefits, possible late deleterious effects, and the potential role of TLI as induction therapy remain to be elucidated.

Acute Disease↗
PubMed1995

Circulatory support for myocardial infarction with ventricular arrhythmias.

Profound circulatory failure developed in a 45-year-old man after an acute myocardial infarction. A left ventricular assist device was used successfully to bridge the patient to transplantation despite recurrent and medically refractory ventricular arrhythmias that lasted from the second through the 12th day of circulatory support.

Arrhythmias, Cardiac↗
PubMed1995

Cardiac transplant coronary artery disease. A multivariable analysis of pretransplantation risk factors for disease development and morbid events.

Coronary artery disease after cardiac transplantation is a major obstacle to long-term survival. The development and progression of coronary artery disease after cardiac transplantation was analyzed in 217 consecutive patients undergoing transplantation. The actuarial freedom from any coronary artery disease (by angiography or autopsy) was 81% at 2 years and 20% at 8 years after transplantation. Coronary artery disease was more prevalent in male than female patients (30% versus 50% free of coronary artery disease at 5 years, p = 0.01). By multivariable analysis, pretransplantation risk factors identified for coronary artery disease included pretransplantation positive cytomegalovirus serologic status of the recipient (p = 0.002) and older donor age (p = 0.07). Progression of coronary artery disease was variable in both time of onset and rate. Earlier detection did not result in more rapid progression. Coronary events severe enough for retransplantation (n = 8) and/or death from coronary artery disease (n = 9) occurred in 15 patients, of whom four underwent retransplantation. The actuarial freedom from coronary events was 88% at 5 years and 79% at 8 years. By multivariable analysis, only male recipient (p = 0.05) was a risk factor for coronary events. Seven of the 15 patients (47%) with coronary events died suddenly of coronary artery disease without prior angiographic evidence of severe coronary disease. Coronary artery disease is progressive. Improved surveillance methods are required to detect the disease and institute timely intervention to prevent the occurrence of unanticipated death.

Actuarial Analysis↗
PubMed1995

Single right coronary artery assessed by contrast angiography and transoesophageal echocardiography.

Contrast angiography is the gold standard for the assessment of the site and severity of coronary artery narrowing. Transoesophageal echocardiography is recognized as a feasible technique in assessing coronary artery anomalies. Our patient had arteriosclerotic narrowing in a single right coronary artery with poor distal opacification during contrast injection. Combining transoesophageal echocardiography with contrast angiography helped us in visualizing a surgically accessible vessel on the anterior wall of the left ventricle.

Arteries↗
PubMed1995

The impact of aortic valve homografts on the treatment of aortic prosthetic valve endocarditis.

Prosthetic valve endocarditis, which is an uncommon but potentially fatal complication of valve replacement, may result in annular abscess formation (mechanical valves) or primarily leaflet infection (xenografts and homografts). Insertion of a mechanical or xenograft valve in the setting of aortic root infection carries a risk of reinfection, which is highest in the first 4 months after valve replacement. In contrast, the homograft aortic valve does not have this early risk of prosthetic valve endocarditis, but instead a constant and low risk across time. Because of this apparent intrinsic resistance to infection, the aortic homograft valve is the replacement device of choice for prosthetic valve endocarditis. An additional advantage of the homograft aortic valve for prosthetic valve endocarditis is the fact that this device has the flexibility to enable its use even in extensive aortic root destruction, including left ventriculo-aortic discontinuity. The homograft valve can be inserted as a root replacement after excision of the infected aortic root, or as a subcoronary or cylindrical technique for less extensive infection.

Aortic Valve↗
PubMed1994

Ventricular assist: experience with a pulsatile heterotopic device.

The successes achieved in bridging patients to transplantation and to recovery of the native heart argue strongly for further development and wider application of mechanical circulatory assist devices. It is possible that even higher success rates can be achieved with earlier use of VADs, particularly in patients who cannot separate from cardiopulmonary bypass. There are several important questions and problems that must be addressed before the wider application of VADs in acute heart failure. How can one reliably and expeditiously distinguish patients who will separate from bypass and survive if given additional time on conventional cardiopulmonary bypass from patients who are destined to require mechanical assistance? How can the problems with post-bypass organ damage be minimized, and how can patients with irreversible organ injury be distinguished from patients with reversible dysfunction? How can the problems with post-implant bleeding, infection, and thromboembolism be minimized? Perhaps the most important problem is how to treat patients who survive VAD implantation, but whose hearts fail to recover. The only alternatives at the present time are removal of the device with almost certain death, or cardiac transplantation. The development of chronically implantable VADs (ie, expected duration of support 5 years or more) will provide an excellent alternative for patients who are not optimal transplant recipients or for whom there is not a donor heart available. The number of patients that will be in this category and the cost per patient year of survival are factors that will weight heavily in the decisions made by the federal government regarding clinical application of this technology.

Acute Disease↗
PubMed1994

The Ross operation--early echocardiographic comparison of different operative techniques.

Fifty-four consecutive patients underwent aortic valve replacement with a pulmonary autograft (Ross operation) over an 18-month period. It was inserted as an intra-aortic cylinder in 13 patients and as a total aortic root replacement in 41; unwrapped in 16, partially wrapped with autologous pericardium in 12 and completely wrapped with bovine pericardium in 13. There were two cardiac deaths, one death from mediastinitis, and two early reoperations to replace an incompetent autograft. Comparison of postoperative echocardiographic data showed a higher incidence of moderate and severe autograft incompetence in the intra-aortic cylinder group and also in the subset without previous operation which had a total root replacement without a complete wrap. Autograft function was best in the group which received a total root replacement with a complete wrap and in those with previous cardiac surgery who received an unwrapped autograft. This preliminary information with short follow up supports the use of complete wrapping of the autograft when it is used as a total root replacement particularly in older patients without previous cardiac surgery in whom future autograft growth is not desirable.

Adolescent↗
PubMed1993

Use of expanded polytetrafluoroethylene pericardial substitute with ventricular assist devices.

Expanded polytetrafluoroethylene membrane was used to reconstruct the pericardium after ventricular assist device insertion in 7 consecutive patients. One patient remains on support with the membrane in place and 6 have had the membrane removed. The expanded polytetrafluoroethylene membrane protected the device cannulas during repeat sternotomy and expedited the dissection of the heart and great vessels at the time of device removal. Reconstruction of the pericardium with expanded polytetrafluoroethylene membrane is recommended at the time of ventricular assist device insertion.

Foreign-Body Reaction↗
PubMed1993

Determinants of heart-lung transplantation outcomes: results of a consensus survey.

Substantial progress has been made in clinical heart-lung transplantation. Although outcomes vary across centers, 1-year patient survival is now 59%. This study was an attempt to assess consensus among transplant program directors regarding the major determinants of patient outcome. In the National Cooperative Transplantation Study we evaluated consensus through a survey of all heart-lung transplant programs active in 1988. Of the eligible programs, 23 (85%) returned completed surveys. Data on the medical and surgical determinants of outcome were analyzed. There was considerable consensus among program directors as to the importance of several factors. The three most critical predictors of favorable outcomes were periodic pulmonary function tests to detect rejection (85.7%), avoidance of use of prednisone during the first 14 days after transplantation (76.2%), and annual left and right heart catheterization with coronary arteriography (76.2%). Several approaches were considered undesirable or unnecessary. These included electrocardiogram as standard rejection monitoring technique (71.4%), cytoimmunological monitoring as standard rejection monitoring technique (66.7%), and routine steroid discontinuation after transplantation (66.7%). On various other treatment approaches there was little evidence of consensus. These included prophylaxis with acyclovir and severe bronchiolitis as a criterion for retransplantation. Although controversial, consensus conferences are one means by which to evaluate technological innovations. Based on their results, practice guidelines can be developed to better inform third-party payers on issues related to transplantation.

Data Collection↗
PubMed1993

Immunosuppressive therapy as a determinant of transplantation outcomes.

Although surgical proficiency is essential to the immediate outcome of transplantation, long-term success depends upon how adequately the transplantation recipient is managed. Immunosuppression, the most critical aspect of after care, is subject to wide variation. In January 1990, a survey was sent to the directors of all transplant programs in the United States performing one or more kidney, heart, liver, heart-lung, or pancreas transplant in 1988. Detailed data were obtained on both the drugs and methods used for induction and maintenance immunosuppression, as well as the treatment of rejection. Each program director was asked to rank each immunosuppressive approach according to its perceived impact on patient outcomes. Over 85% of all eligible program directors completed the survey. There is no evidence of survey respondent bias. The use of polyclonal and monoclonal agents for induction immunosuppression was favored most by pancreas program directors (72-76%). These agents were least preferred by liver transplant programs (35-37%). About half of kidney, heart, and heart-lung program directors preferred these agents. Triple-drug therapy consisting of CsA, PRED, and AZA was considered the most preferable maintenance protocol for all transplants (i.e., kidney, 89%; heart, 94%; liver, 88%; heart-lung, 86%; pancreas, 96%). Either i.v. steroids or OKT3 were regarded as the preferred approaches for the treatment of acute or resistant rejection. Finally, the acceptability of outpatient treatment of rejection varied by transplant type (i.e., kidney, 9%; heart, 58%; liver, 5%; heart-lung, 29%; pancreas, 8%). Although there are similarities in the ratings of various aspects of immunosuppressive therapy, there are important differences. This information is critical to anticipate the implications of new immunosuppressive agents and to evaluate changes in the use of existing drugs and therapeutic approaches.

Data Collection↗
PubMed1993

Influence of left ventricular assist on valvular regurgitation.

BACKGROUND: The effects of mechanical left ventricular assist on the nonassisted right ventricle have not been fully elucidated. Current information indicates that the right ventricle benefits from a lower left atrial pressure; however, ventricular septal shifting and increased venous return caused by left ventricular assist impair right ventricular function. Acute intraoperative alterations in mitral and tricuspid valve regurgitation (MR and TR, respectively) may occur as a result of mechanical left ventricular assist but have not yet been documented. METHODS AND RESULTS: Eight patients undergoing implantation of a left ventricular assist device (LVAD) as a bridge to transplantation were studied during surgery by transesophageal echocardiography. MR was present in seven of eight patients, and TR was present in eight of eight patients before LVAD implant (mean MR jet area, 10.6 +/- 2.4 cm2, mean TR jet area, 4.8 +/- 1.0 cm2). Immediately after LVAD placement, MR was still present in seven of eight patients, and TR was present in eight of eight patients (mean MR jet area, 4.2 +/- 0.9 cm2; mean TR jet area, 8.4 +/- 1.9 cm2) (P < .05 preimplant versus postimplant jet area). These changes in MR and TR were associated with a decrease in left ventricular end-systolic dimension (62 +/- 4 versus 48 +/- 3 mm) and an increase in right ventricular end-systolic dimension (31 +/- 4 versus 40 +/- 5 mm) (P < .05 preimplant versus postimplant end-systolic dimension). No patients developed progressive right ventricular failure during 70 to 279 days of LVAD support. CONCLUSIONS: Mechanical left ventricular assist causes an acute decrease in preexisting MR. However, left ventricular assist may acutely worsen TR, presumably by shifting the ventricular septum leftward and increasing venous return to the right ventricle.

Cardiomyopathy, Dilated↗
PubMed1993

Long-term function of cryopreserved aortic homografts. A ten-year study.

Cryopreserved aortic valve homografts have become an accepted aortic valve substitute, but long-term studies with echocardiographic assessment of valve function are largely unavailable. Between 1981 and January 1, 1991, a total of 178 patients aged 9 months to 80 years (median 46 years) underwent implantation of a cryopreserved aortic valve homograft. Serial two-dimensional Doppler echocardiographic studies were obtained in 149 patients. Overall survival was 91% at 1 year and 85% at 8 years. Survival of patients undergoing isolated primary infracoronary aortic valve replacement was 99% at 1 month and 94% at 8 years. Twelve patients underwent homograft explanation. Freedom from explantation for leaflet degeneration was 95% at 8 years. Freedom from presumed leaflet failure (valve degeneration at explantation or aortic insufficiency grade 3/4 or more without reoperation on echocardiography) was 94% at 5 years and 85% at 8 years. By multivariable analysis younger recipient age was the only risk factor identified for leaflet failure. Ninety-five percent of patients followed up for 4 or more years were in New York Heart Association class I or II.

Actuarial Analysis↗
PubMed1992

Usefulness and limitations of transesophageal echocardiography in the assessment of proximal coronary artery stenosis.

To assess the usefulness of transesophageal echocardiography in the evaluation of proximal coronary artery stenosis, 111 consecutive patients (mean age 61 years) who had intraoperative transesophageal echocardiography and coronary angiography within 1 week of surgery were studied. Transesophageal echocardiography visualized the entire length of the left main artery (0.2 to 2.2 cm, mean 0.93), 0.2 to 2.2 cm of the proximal left anterior descending artery and 0.1 to 3.4 cm of the proximal left circumflex artery in 103 patients (93%) and 0.1 to 4.6 cm of the proximal right coronary artery in 55 patients (49%). In the coronary artery segments visualized by echocardiography and compared with the corresponding angiographic segments, transesophageal echocardiography correctly identified 23 (96%) of 24 left main stenoses, 11 (78%) of 14 stenoses involving the left anterior descending artery, 6 (75%) of 8 left circumflex stenoses and all 7 stenoses (100%) of the right coronary artery. In all seven patients with ostial stenosis (left main artery in five and right coronary artery in two), the condition was correctly diagnosed by this technique. The sensitivity and specificity of transesophageal echocardiography in the overall evaluation of proximal coronary artery stenosis as customarily defined by angiography were 96% and 99% for the left main artery, 48% and 99% for the left anterior descending artery, 67% and 100% for the left circumflex artery and 37% and 100% for the right coronary artery, respectively. The distance of the stenotic lesion from the origin of the vessel by transesophageal echocardiography also correlated well with that measured by angiography (r = 0.63 to 0.99).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Cytomegalovirus colitis presenting as hematochezia and requiring resection.

Cytomegalovirus infection is one of the most prevalent viral infections affecting recipients of cardiac allografts. Of the various severe systemic manifestations, those in the gastrointestinal tract have a unique way of presenting, specifically in the colon where a process related to cytomegalovirus infection that involves all layers, with dilatation as a prominent clinical feature, has been suggested. We report herein a case of patient with a heart allograft who had severe episodes of rejection that responded to boosting doses of steroids. Because of persistent fever, diarrhea, hematochezia, and computed tomographic findings of the abdomen that showed a highly abnormal appearance of the ascending and transverse segments of the colon, this patient subsequently underwent celiotomy. The involved segment of the colon was found to have severe inflammation with mucosal necrosis; a subtotal colectomy was done. The abundant cytomegalovirus inclusions found in the vascular endothelium of the removed damaged segment of the colon suggest that cytomegalovirus may have been a causal factor in this form of colitis. The patient recovered uneventfully.

Colitis↗
PubMed1992

Variation in cryolesion penetration due to probe size and tissue thermal conductivity.

The purpose of this study is to present data comparing the penetration of cryolesions created by various sizes and shapes of cryoprobes in human cadaveric myocardium, fat, and tissue of the central fibrous body. Ten cryolesions were made for each combination of tissue and cryoprobe studied. All cryolesions enlarged most rapidly during the first minute of cryothermia (p less than 0.01). Maximal cryothermic penetration into nontrabeculated myocardium was 8.5 +/- 0.5 mm (15-mm flat probe) and 6.1 +/- 1.0 mm (5-mm small probe). Maximal cryothermic penetration into trabeculated myocardium was 9.4 +/- 1.0 mm (10-mm cone-tipped probe) and 7.4 +/- 0.5 mm (10-mm flat probe). Maximal cryothermic penetration into fat was 4.7 +/- 0.7 mm (15-mm flat probe) and 3.9 +/- 0.7 mm (5-mm flat probe). The deeper penetration of cryothermia into myocardium as compared with fat (p less than 0.05) is related to the lower thermal conductivity of fat. Maximal cryothermic penetration of the central fibrous body was similar to that of the myocardium with transmural freezing of the central fibrous body after 4.4 +/- 0.3 minutes of cryothermia. These data can be used when determining the optimal cryothermic exposure for ablation of arrhythmogenic tissue.

Arrhythmias, Cardiac↗