Prioritizing conservation practice locations for effective water quality improvement using the Agricultural Conservation Planning Framework (ACPF) and the Soil and Water Assessment Tool (SWAT)

Adopting the right agricultural conservation practices (CPs) at the right place is critical to maximizing water quality benefits. The Agricultural Conservation Planning Framework (ACPF) tool identifies all potential CPs and their locations within a target watershed based on the landscape characteristics. The ACPF tool suggests hundreds of CP locations in a watershed, making it challenging to prioritize the CP implementation. We develop and demonstrate an efficient approach using a multicriteria ranking technique for prioritizing the CPs suggested by ACPF, considering pollution hotspots and CP cost and effectiveness to support decision-makers. The pollution hotspots are estimated with simulations from an ecohydrological model, the Soil and Water Assessment Tool (SWAT). The CP cost and effectiveness were estimated from CP installation costs and pollutant reduction efficiencies from the literature. The methodology was demonstrated in the Conewago and Mahantango watersheds in Pennsylvania, US, for grassed waterways (GWWs) and water and sediment control basins (WASCOBs) for sediment load reduction. Multiple CP prioritization scenarios were evaluated with individual and combined criteria for reductions in total sediment load, yield (loading per area), and cost. In single criterion-based prioritization, the cost-based and load-based prioritization indicated cost efficiency and fewer CPs, respectively. The yield-based approach correctly prioritized CPs in sediment loss hotspots in the case study watersheds; however, it needed more CPs to meet the target reductions. The multicriteria approach efficiently prioritized CPs in sediment hotspots to meet target reductions. Although this approach was demonstrated in two case study watersheds and for sediment loss reduction, it is applicable for any location or pollutant for which similar input variables can be provided, thereby providing a means for prioritizing the results of ACPF for implementation in the Mid-Atlantic region of the US.

A feasibility study into the use of three-dimensional printer modelling in acetabular fracture surgery

There are a number of challenges associated with the operative treatment of acetabular fractures. The approach used is often extensive, while operative time and perioperative blood loss can also be significant. With the proliferation of 3D printer technology, we present a fast and economical way to aid the operative planning of complex fractures. We used augmented stereoscopic 3D CT reconstructions to allow for an appreciation of the normal 3D anatomy of the pelvis on the fractured side and to use the models for subsequent intraoperative contouring of pelvic reconstruction plates. This leads to a reduction in the associated soft tissue trauma, reduced intraoperative time and blood loss, minimal handling of the plate, and reduced fluoroscopic screening times. We feel that the use of this technology to customize implants, plates, and the operative procedure to a patient's unique anatomy can only lead to improved outcomes.

Re-admissions to the State Hospital at Carstairs, 1992-1997

OBJECTIVE

To examine the incidence and characteristics of re-admissions to the State Hospital over the six year inclusive period of January 1992 to December 1997. RESONS FOR THE STUDY: RISK ASSESSMENT: A re-admission to a high-security setting may be the result of a failed risk assessment at the time of discharge. An analysis of re-admissions might reveal facts that will improve risk prediction. In this context every re-admission to maximum security should qualify for critical incident appraisal. A re-admission could also indicate prudent risk management where the patient is readmitted prior to the occurrence of any new incident. Our analysis may give an indication how risk prediction and risk management is functioning in the Forensic Psychiatry setting.

HEALTH ECONOMICS

Patient numbers at the State Hospital have exceeded planning predictions. In the early 1990s the prediction was that numbers would level off at around 200 patients. Instead admission rates continued to rise and the State Hospital in-patient population has on occasion reached its maximum. This trend has continued throughout the decade with the daily patient numbers averaging 236, 248, 252 and 249 in the last four years (1997-2000). In this context the role played by re-admissions is an important health economics issue.

DESIGN

Data gathered from the medical records department and examination of medical case files, entered into a database, and subsequently analysed using a variety of tools. Descriptive statistics for the total State Hospital patient population between 1992-1994 were taken from a published survey. Other comparative analyses were undertaken using data from previously published studies.

SETTING

The data originate from the State Hospital, Carstairs, Lanarkshire, which is the only psychiatric hospital in Scotland to offer maximum-security care. Patients are admitted from ordinary psychiatric hospitals as well as from a penal setting. The maximum number of staffed beds is currently 257. These comprise an admission unit, two rehabilitation units including one with flatlet accommodation, a specialist learning difficulties unit, an all female unit and six male wards. The Hospital is staffed by psychiatrists, GPs, psychologists, social workers, psychiatric nurses including nurse specialists, occupational therapists, and other specialist staff employed in the education, occupations and recreation departments.

RESULTS AND CONCLUSIONS

Annual re-admission rate, averaged over 1992-1997 is 22.3% of all patient discharges in the hospital. This is broadly in line with other studies quoted in the literature. The re-admission rate co-varied with first admission rate at an almost constant ratio of 0.38 over the six-year period of study. There is no apparent systematic reason for this phenomenon. The most apparent risk factor was a previous admission to the State Hospital of less than a years duration. Compared with the current average length of stay of five years, this must be considered a short admission. Patients with an above average length of stay were rarely readmitted. Most re-admissions returned during the first year after discharge and nearly all had returned within a three-year period. State patients on a Restriction Order who will be subject to conditional discharge with ongoing supervision fared best and were least likely to be re-admitted. However such patients are also likely to have an above average length of stay. Convicted prisoners and remanded offenders were most likely to be readmitted. There was almost no crossover between the civil and criminal populations when their status was reviewed on re-admission. This raises the question, whether these two patient groups should be perceived and managed differently. The recent move to build medium secure units in Scotland, such as the Orchard Clinic in Edinburgh, now makes this a practical option. This finding also suggests that, in Scotland, bed closures in Mental Hospitals are not leading to a decant of mentally disordered patients into the penal system, at least at the level of more serious offending. Violence was overall the most common reason for return to the State Hospital. Violence was the predominant reason for re-admission from a local hospital whereas relapse of symptoms, where such symptoms were associated with dangerous behaviour in the past, was rarely given as a reason. In contrast, relapse was the predominant reason for return from prison. This may be related to inadequate prison hospital facilities rather than good risk prediction.

Production of the next-generation library virtual tour

While many libraries offer overviews of their services through their Websites, only a small number of health sciences libraries provide Web-based virtual tours. These tours typically feature photographs of major service areas along with textual descriptions. This article describes the process for planning, producing, and implementing a next-generation virtual tour in which a variety of media elements are integrated: photographic images, 360-degree "virtual reality" views, textual descriptions, and contextual floor plans. Hardware and software tools used in the project are detailed, along with a production timeline and budget, tips for streamlining the process, and techniques for improving production. This paper is intended as a starting guide for other libraries considering an investment in such a project.

Implantable cardioverter defibrillator patch erosion in a heart transplant patient

A 57-year-old man who had received an automatic implantable cardioverter defibrillator and subsequent orthotopic heart transplant presented to medical attention for hemoptysis. The hemoptysis was caused by the migration of the left ventricular patch of the automatic implantable cardioverter defibrillator, which had been left in place at the time of orthotopic heart transplant. The patch had eroded into the left lung. We recommend that implantable cardioverter defibrillators be removed completely at the time of heart transplantation to prevent subsequent complications.

Concomitant subclavian and coronary artery disease

BACKGROUND

Proximal subclavian artery occlusive disease in the presence of a patent internal mammary artery used as a conduit for a coronary artery bypass graft procedure may cause reversal of internal mammary artery flow (coronary-subclavian steal) and produce myocardial ischemia.

METHODS

We reviewed outcome to determine whether subclavian artery revascularization can provide effective protection from and treatment for coronary-subclavian steal. Between 1985 and 1997, 20 patients had either concomitant subclavian and coronary artery disease diagnosed before operation (group 1, 5 patients) or symptomatic coronary-subclavian steal occurring after a previous coronary artery bypass graft procedure (group 2, 15 patients). Patients in group 1 received direct subclavian artery bypass and a simultaneous coronary artery bypass graft procedure in which the ipsilateral internal mammary artery was used for at least one of the bypass conduits. Patients in group 2 received either extrathoracic subclavian-carotid bypass (5 patients, 33.3%) or percutaneous transluminal angioplasty and stenting (10 patients, 66.7%) as treatment for symptomatic coronary-subclavian steal.

RESULTS

All patients were symptom-free after intervention. One patient treated with percutaneous transluminal angioplasty and stenting died of progressive renal failure. Follow-up totaled 58.5 patient-years (mean, 3.1 years/patient). In group 1, primary patency was 100% (mean follow-up, 3.7 years). In group 2, one late recurrence was treated by operative revision, yielding a secondary patency rate of 100% (mean follow-up, 2.9 years).

CONCLUSIONS

Subclavian artery revascularization can provide effective protection from and treatment for coronary-subclavian steal with acceptably low operative risk. Midterm follow-up demonstrates good patency.

A molecular phylogeny of Phytophthora and related oomycetes

Phylogenetic relationships among 50 Phytophthora species and between Phytophthora and other oomycetes were examined on the basis of the ITS sequences of genomic rDNA. Phytophthora grouped with Pythium, Peronospora, and Halophytophthora, distant from genera in the Saprolegniales. Albugo was intermediate between these two groups. Unlike Pythium, Phytophthora was essentially monophyletic, all but three species forming a cluster of eight clades. Two clades contained only species with nonpapillate sporangia. The other six clades included either papillate and semipapillate, or semipapillate and nonpapillate types, transcending traditional morphological groupings, which are evidently not natural assemblages. Peronospora was related to P. megakarya and P. palmivora and appears to be derived from a Phytophthora that has both lost the ability to produce zoospores and become an obligate biotroph. Three other Phytophthoras located some distance from the main Phytophthora-Peronospora cluster probably represent one or more additional genera.

Cryoablation of incessant ventricular tachycardia: case report and long-term follow-up

We report the case of a 52-year-old man who had incessant ventricular tachycardia despite treatment with antiarrhythmic agents. Placement of an implantable cardioverter/defibrillator, radiofrequency ablation, and antitachycardia pacing were ineffective. He underwent intraoperative arrhythmia mapping and cryoablation at our institution. Eighteen months later, he remained free of arrhythmia. He was in New York Heart Association functional class II with an ejection fraction of 30%.

Sinus of Valsalva aneurysm or fistula: management and outcome

BACKGROUND

Few large or long-term series exist regarding the management of patients with sinus of Valsalva aneurysms or fistulas (SVAFs).

METHODS

Between 1956 and 1997, 129 patients presented with a ruptured (64 cases; 49.6%) or nonruptured (65 cases; 50.4%) SVAF. The patients included 88 men and 41 women, with a mean age of 39.1 years. Associated findings included a history of endocarditis (42 cases; 32.6%), a bicuspid aortic valve (21 cases; 16.3%), a ventricular septal defect (15 cases; 11.6%), and Marfan's syndrome (12 cases; 9.3%). Operative procedures included simple plication (61 cases; 47.3%), patch repair (52 cases; 40.3%), aortic root replacement (16 cases; 12.4%), and aortic valve replacement/repair (75 cases; 58.1%).

RESULTS

There were five in-hospital deaths (3.9%): four due to preexisting sepsis and endocarditis and one that followed dehiscence of the repair in a patient with Marfan's syndrome. Two patients (1.6%) had strokes during the early postoperative period. The survivors were followed up for 661.1 patient-years (5.3 years/patient). The following late complications occurred: prosthetic valve malfunction (5 cases; 3.9%), prosthetic valve endocarditis (3 cases; 2.3%), SVAF recurrence (2 cases; 1.6%), thrombosis (1 case; 0.8%), and anticoagulation-related bleeding (1 case; 0.8%).

CONCLUSIONS

Resection and repair of SVAF entails an acceptably low operative risk and yields long-term freedom from symptoms. Early, aggressive treatment is recommended to prevent endocarditis or lesional enlargement, which causes worse symptoms and necessitates more extensive repair.

Origin of a new Phytophthora pathogen through interspecific hybridization

Plant disease epidemics resulting from introductions of exotic fungal plant pathogens are a well known phenomenon. An associated risk-that accelerated pathogen evolution may be occurring as a consequence of genetic exchange between introduced, or introduced and resident, fungal pathogens-is largely unrecognized. This is, in part, because examples of natural, interspecific hybridization in fungi are very rare. Potential evolutionary developments range from the acquisition of new host specificities to emergence of entirely new pathogen taxa. We present evidence from cytological behavior, additive nucleotide bases in repetitive internal transcribed spacer regions of the rRNA-encoding DNA (rDNA), and amplified fragment length polymorphisms of total DNA that a new, aggressive Phytophthora pathogen of alder trees in Europe comprises a range of heteroploid-interspecific hybrids involving a Phytophthora cambivora-like species and an unknown taxon similar to Phytophthora fragariae. The hybrids' marked developmental instabilities, unusual morphological variability, and evidence for recombination in their internal transcribed spacer profiles indicates that they are of recent origin and that their evolution is continuing. The likelihood of such evolutionary events may be increasing as world trade in plants intensifies. However, routine diagnostic procedures currently in use are insufficiently sensitive to allow their detection.

Right atrial bypass grafting for central venous obstruction associated with dialysis access: another treatment option

PURPOSE

Central venous obstruction is a common problem in patients with chronic renal failure who undergo maintenance hemodialysis. We studied the use of right atrial bypass grafting in nine cases of central venous obstruction associated with upper extremity venous hypertension. To better understand the options for managing this condition, we discuss the roles of surgery and percutaneous transluminal angioplasty with stent placement.

METHODS

All patients had previously undergone placement of bilateral temporary subclavian vein dialysis catheters. Severe arm swelling, graft thrombosis, or graft malfunction developed because of central venous stenosis or obstruction in the absence of alternative access sites. A large-diameter (10 to 16 mm) externally reinforced polytetrafluoroethylene (GoreTex) graft was used to bypass the obstructed vein and was anastomosed to the right atrial appendage. This technique was used to bypass six lesions in the subclavian vein, two lesions at the innominate vein/superior vena caval junction, and one lesion in the distal axillary vein.

RESULTS

All patients except one had significant resolution of symptoms without operative mortality. Bypass grafts remained patent, allowing the arteriovenous grafts to provide functional access for 1.5 to 52 months (mean, 15.4 months) after surgery.

CONCLUSION

Because no mortality directly resulted from the procedure and the morbidity rate was acceptable, this bypass grafting technique was adequate in maintaining the dialysis access needed by these patients. Because of the magnitude of the procedure, we recommend it only for the occasional patient in whom all other access sites are exhausted and in whom percutaneous dilation and/or stenting has failed.

The Information Commons: a model for (physical) digital resource centers

Since its planning, construction, and opening in 1996, the Information Commons, located in The University of Iowa's Hardin Library for the Health Sciences, has served as a common ground for self-directed learning, information research, hands-on class sessions, and multimedia development. Initiatives launched from the Information Commons not only have helped increase the visibility of Hardin Library as an environment well equipped to support traditional research and education needs, but have promoted the library as a campus leader and viable partner in planning and delivering digital technologies effectively. Ongoing initiatives have focused on better integrating the library's services and resources with the curricula and research needs of the university's health sciences units. This paper describes the facility, its programmatic elements, and its impact on education, communication, and technology trends in an academic health sciences setting. Particular attention is paid to initiatives launched during the first two years of operation. This paper also discusses plans for expansion of the facility.

Concomitant occlusive disease of the coronary arteries and great vessels

BACKGROUND

Although an increasing number of elderly and high-risk patients, including those with generalized atherosclerosis, are undergoing coronary revascularization, few reports exist regarding the management of patients who have both occlusive disease of the great vessels and coronary artery disease.

METHODS

Between 1972 and 1996, 31 consecutive patients (mean age, 56.5 years; 74% men) with multivessel coronary artery disease and symptomatic occlusive disease of the great vessels (25 single-vessel, 80.6%; 6 multiple-vessel, 19.4%) had 40 great vessels reconstructed by transthoracic bypass (n = 17, 42.5%), transthoracic endarterectomy (n = 8, 20%), or extrathoracic bypass (n = 15, 37.5%). All patients had simultaneous coronary artery bypass grafting (mean, 2.6 grafts per patient), and 8 patients had 10 distal carotid bifurcation endarterectomies (6 staged, 4 simultaneous).

RESULTS

The early primary patency rate was 100%, and symptoms resolved completely in all 31 patients. There was 1 in-hospital death (3.2%) in a patient who had a respiratory arrest 11 days after operation. Perioperative morbidity included two myocardial infarctions (6.5%) and one opposite-hemisphere, embolic stroke (3.2%). Long-term follow-up of the 30 survivors (167.4 patient-years; mean, 5.6 years per patient) documented 5- and 10-year actuarial survival rates of 88.6% and 60.4%, respectively, with a 100% late brachiocephalic primary patency rate. Ten-year actuarial rates of freedom from the following events were as follows: death, 60.4%; myocardial infarction, 82.5%; stroke, 90.9%; percutaneous transluminal coronary angioplasty or redo coronary artery bypass grafting, 95.2%; and vascular operation or amputation, 78.4%.

CONCLUSIONS

Depending on the anatomic distribution of the disease, an integrated approach to great vessel reconstruction that incorporated transthoracic and extrathoracic approaches and techniques of endarterectomy and bypass resulted in few adverse outcomes and excellent long-term patency. Simultaneous revascularization of the great vessels and coronary arteries can produce immediate and long-term, symptom-free outcome with acceptably low operative risk.

The tigA gene is a transcriptional fusion of glycolytic genes encoding triose-phosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase in oomycota

Genes encoding triose-phosphate isomerase (TPI) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) are fused and form a single transcriptional unit (tigA) in Phytophthora species, members of the order Pythiales in the phylum Oomycota. This is the first demonstration of glycolytic gene fusion in eukaryotes and the first case of a TPI-GAPDH fusion in any organism. The tigA gene from Phytophthora infestans has a typical Oomycota transcriptional start point consensus sequence and, in common with most Phytophthora genes, has no introns. Furthermore, Southern and PCR analyses suggest that the same organization exists in other closely related genera, such as Pythium, from the same order (Oomycota), as well as more distantly related genera, Saprolegnia and Achlya, in the order Saprolegniales. Evidence is provided that in P. infestans, there is at least one other discrete copy of a GAPDH-encoding gene but not of a TPI-encoding gene. Finally, a phylogenetic analysis of TPI does not place Phytophthora within the assemblage of crown eukaryotes and suggests TPI may not be particularly useful for resolving relationships among major eukaryotic groups.

Is an integrated approach warranted for concomitant carotid and coronary artery disease?

BACKGROUND

The management of patients with severe, concomitant coronary and carotid artery occlusive disease is controversial.

METHODS

Between 1975 and 1996, 512 patients (mean age, 64.9 years; 70% male) were admitted for coronary revascularization; 316 (61.7%) had asymptomatic, severe carotid disease (stenosis > 70%) and 196 (38.3%) had symptomatic carotid disease (159 [31.1%] with transient ischemia and 37 [7.2%] with completed stroke). In group 1, coronary revascularization and carotid endarterectomy were simultaneously performed in 255 patients (49.8%) with unstable angina. In group 2 (staged approach), carotid endarterectomy was performed before coronary revascularization in 257 patients (50.2%) without unstable angina.

RESULTS

Before 1986, the incidence of stroke and death was greater in group 1 (n = 149) than in group 2 (n = 156) (14 [9.4%] versus 4 [2.6%]; p < 0.01). Since 1986, outcomes in group 1 (n = 106) and group 2 (n = 101) have been similar for stroke (2 [1.9%] versus 2 [2.0%]), death (4 [3.8%] versus 3 [3.0%]), and myocardial infarction (4 [3.8%] versus 5 [5.0%]). Significant univariate and multivariate predictors of adverse outcome were primarily heart-related (reoperation, intraaortic balloon use, ejection fraction < 0.50, and angina grade 4 for death; age > 70 years and congestive heart failure for stroke).

CONCLUSIONS

Despite highly selected populations, contemporary surgical results do not indicate that staged treatment of severe, concomitant coronary and carotid artery occlusive disease has an advantage over simultaneous treatment. Advances in myocardial protection and perioperative hemodynamic management may account for the low incidences of stroke and death in these operations.

Ridge widening for the thin maxilla: a clinical report

The thin maxilla may present an anatomic limitation to the placement of endosseous implants. Separating the cortical plates and widening the alveolar ridge with simultaneous placement of implants is one surgical method for management of this problem. Guided tissue regeneration techniques may be used in conjunction with this ridge widening procedure.

Implants in adolescents: a literature review and case reports

A retrospective review of a limited number of adolescents with implants was conducted to compare the behavior of these implants with studies in which implants had been placed in growing animals. Growth of the facial skeleton is also reviewed. Implants placed in the growing alveolus behave like ankylosed teeth and become submerged as the surrounding bone grows. Cessation of facial growth should occur prior to implant placement in adolescents.

Effects of donor position on harvested lung quality

Potential lung donors are frequently maintained in one position for prolonged periods of time prior to harvest. This study was designed to determine if the effects of gravity induced by maintaining an animal model in the supine position for 24 hr would have adverse effects on the harvested lung. Group 1 pigs were anesthetized, instrumented, mechanically ventilated, and the lungs harvested within 90 min. Group 2 pigs were anesthetized, instrumented, and mechanically ventilated in an identical manner then maintained in the same dorsal-spinal recumbency position for 24 hrs. Hemodynamic and respiratory parameters were stable and not statistically different between the two groups for the baseline and 1 hr time period measurements. There were no significant differences between the two groups for shunt fractions, wet/dry ratios, blood flow distribution, or flush solution distribution. We conclude that in anesthetized pigs there is no evidence that routine repositioning protocols improve blood flow distribution, shunting, or dependent edema.

Carotid endarterectomy. Results in asymptomatic and symptomatic patients

Objective evidence of the benefit of carotid endarterectomy in preventing stroke and its significant sequelae has recently been demonstrated by prospective trials. The salutary results depend on meeting strict operative outcome criteria as established by the American Heart Association. We retrospectively analyzed 265 consecutive carotid endarterectomies performed in 248 patients during 1 year at our institution. The perioperative mortality rate was 0; late mortality occurred 6 months postoperatively in 1 of 2 patients who experienced a perioperative stroke. The combined perioperative mortality and stroke rate was 0.8%. The combined mortality and stroke rate in patient subgroups was 0.7% (1/151) for asymptomatic patients, 1.6% (1/64) for symptomatic patients who had presented with a transient ischemic attack, and 0% (0/50) for symptomatic patients who had presented with a completed stroke. We conclude that the objective postoperative benefits of carotid endarterectomy in treating extracranial cerebrovascular disease can be achieved with low perioperative patient morbidity.

Management of mitral valve stenosis in pregnancy: case presentation and review of the literature

Severe mitral stenosis is a challenging complication in pregnancy. A case is described in which mitral valve replacement was undertaken immediately following caesarean section at 34 weeks' gestation. A review of the literature discusses the evolution of treatment approaches for mitral stenosis in pregnancy, including open mitral commissurotomy and percutaneous mitral commissurotomy with the use of balloon catheters. With balloon procedures, potential risks to the fetus are minimized because the abdomen and pelvis are shielded. In addition, the use of adjunct transesophageal echocardiography shortens fluoroscopic time. In the case described, neither open nor percutaneous mitral commissurotomy were viable options because of moderate-to-severe mitral regurgitation and a heavily calcified valve. This is one of few such cases reported in the literature to date.

The Medicare Participating Heart Bypass Demonstration Project in Houston, Texas. The experience of St. Luke's Episcopal Hospital, Texas Heart Institute, and CardioVascular Care Providers, Inc

While passage of a health care bill remains uncertain, the structure of health care in the United States is nonetheless changing rapidly. In some cases, physicians and hospitals are working more closely with one another to provide high-quality care at lower costs. Patients, physicians, hospitals, and insurers (including the Federal government) can all benefit from such an arrangement. We review here the experience with a program of bundled-free (physician and hospital) cardiovascular care for Medicare patients at the Texas Heart Institute at St. Luke's Episcopal Hospital in Houston, Texas.

Effect of IgM-positive crossmatches on survival in heart transplant recipients

To determine whether an IgM-positive crossmatch adversely affects the results of heart transplantation, we conducted a retrospective study of 125 orthotopic heart transplant recipients. A direct donor-recipient crossmatch was performed retrospectively on sera from all patients by the standard National Institutes of Health (NIH) method and the antihuman globulin (AHG) procedure. The patients were then divided into 3 groups as follows. Group 1 comprised 110 patients with a negative NIH and AHG crossmatch (control group). Group 2 comprised 5 patients with a positive NIH crossmatch and a negative AHG crossmatch. Group 3 comprised 10 patients with positive NIH and AHG crossmatches. All positive crossmatches in group 3 patients converted to negative after treatment of sera with dithioerythritol, indicating that the initial result was due to IgM antibodies. All patients received standard immunosuppressive treatment. An IgM-positive crossmatch did not affect the number or severity of rejection episodes among the 3 groups, nor did it have an effect on the incidence of infection. Whereas coronary artery disease was detected by angiography in 16 of 110 patients (14.6%) in group 1 and in 1 of 10 patients (10%) in group 3 (P = NS), no patient in group 2 was affected. Actuarial survival at 1 and 2 years post-transplant was significantly better for patients with an IgM-positive crossmatch (group 2) (100% survival at 2 years) than for patients with a negative crossmatch (group 1) (73% at 1 year and 71% at 2 years, P < 0.05). Based on our study, the effect of an IgM-positive crossmatch on survival is difficult to interpret because of the small sample size. An IgM-positive crossmatch, however;did not appear to have a deleterious effect on survival. It may be that the IgM antibody has an immunoregulatory role. A larger series of patients with positive crossmatches and longer follow-up will be necessary to evaluate the importance of these results.

Improved survival after extended bridge to cardiac transplantation

In the past, left ventricular assist device (LVAD) support was frequently plagued by complications; thus, bridge to transplantation times were kept short. Increasing evidence suggests that extended bridging provides greater benefit due to improved end-organ perfusion and, thus, generally improved physical condition. To assess whether extended bridging translates into improved long-term survival after transplantation, we reviewed our experience with the HeartMate 1000 IP LVAD (Thermo Cardiosystems, Inc, Woburn, MA). Since January 1988, 19 patients (mean age, 45 +/- 9 years) have undergone extended bridging (mean time, 106 +/- 57 days). Their mean weight was 82 +/- 16 kg, and their mean body surface area was 2.0 +/- 0.2 m2. We define "extended" as the length of support necessary for systemic organ recovery after prolonged heart failure. During support, average pump flow indices ranged from 2.3 to 3.3 L.min-1.m-2, and all patients underwent physical rehabilitation. Between the time of LVAD implantation and explantation, the mean serum creatinine value decreased from 1.63 +/- 0.6 to 1.25 +/- 0.6 mg/dL (p = not significant), and the mean serum total bilirubin value decreased from 2.8 +/- 2.0 to 0.63 +/- 0.11 mg/dL (p < 0.05). All but 1 patient improved from New York Heart Association class IV to class I. Device-related complications were minimal. Twelve control patients ("de facto randomized") who did not receive the LVAD also were evaluated: actuarial survival at 1 year was 0% (p < 0.05); 3 (25%) underwent transplantation and died within 2 months; 9 (75%) died before transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunochemical identification of human endothelial cells on the lining of a ventricular assist device

We are studying the biologic (pseudointimal) lining that forms in the HeartMate (Thermo Cardiosystems, Inc.; Woburn, Massachusetts, USA), a left ventricular assist device with a pusher-plate blood pump, housed in solid titanium with uniquely textured blood-contacting surfaces. Sintered titanium microspheres cover the rigid surface, and integrally textured polyurethane lines the flexing diaphragm. The texture of the blood-contacting surfaces is designed to encourage formation of a biologic pseudointimal lining, which greatly reduces the risk of thromboembolic complications. We performed immunochemical analyses to characterize precisely the pseudointimal lining. Samples were taken from 2 explanted pumps; 1 had supported a patient for 132 days and the other, 189 days. The samples were cultured to detect factor-VIII-related antigen (von Willebrand factor), acetyl low-density lipoprotein receptors, smooth-muscle-cell actin, and surface adhesion molecules specific for monocytes/macrophages. Macrophage cells were predominant in both pumps, but in the 2nd pump, cultures from the center of the diaphragm were positive for acetyl low-density lipoprotein receptor and von Willebrand factor, indicating the presence of endothelial cells. We believe that blood-borne endothelial cells or endothelial cell precursors were deposited on the blood-contacting surfaces, which is an important clinical finding with regard to lowering the risk of thromboembolic complications and reducing the need for systemic anticoagulation in long-term left ventricular assist device patients.

Improved multiorgan function after prolonged univentricular support

Eleven cardiac transplant candidates (all male; mean age, 43.3 years) with multiorgan (hepatic, pulmonary, and/or renal) dysfunction were sustained for prolonged periods (> 30 days) with the HeartMate (Thermo Cardiosystems, Inc, Woburn, MA) left ventricular assist device. We evaluated the effect of extended support on end-organ recovery and on the ultimate outcome of cardiac transplantation. In addition to cardiac failure, 9 patients had hepatic dysfunction, 8 had pulmonary dysfunction, and 6 had renal dysfunction (4 of whom required hemodialysis before left ventricular assist device support). Mean duration of support was 115 days (range, 31 to 233 days). All patients underwent successful transplantation; 10 of these patients survived a mean of 24 months. One patient, who had required hemodialysis and ventilatory support during and after support, experienced progressive multiorgan failure and died 7 weeks after transplantation. Two late deaths after transplantation were unrelated to the device. Overall, patients experienced improvement in cardiac functional class status, and most participated in cardiac rehabilitation programs before transplantation. During left ventricular assist device support, hepatic function returned to normal in 8 patients, pulmonary function recovered in 7, and renal function returned to normal in 4. One patient who required hemodialysis underwent renal transplantation after cardiac transplantation and had complete recovery of renal function. In the current era of donor shortages, gravely ill patients can benefit from a strategy of prolonged left ventricular assist device support. This strategy has proved safe, has allowed for reversal of multiorgan dysfunction, and has produced healthier transplant candidates.

Peripheral organ perfusion augmentation during left ventricular failure. A controlled bovine comparison between the intraaortic balloon pump and the Hemopump

Despite the use of inotropic therapy and the intraaortic balloon pump (IABP), inadequate peripheral organ perfusion and subsequent multiorgan failure from left ventricular dysfunction is a major cause of death following cardiac surgery. To compare the end-organ perfusion provided by the IABP with that of the recently developed Hemopump Cardiac Assist System, blood flow from visceral organs was measured by ultrasonic flow probes during separate periods of support with each of these pumps. Ten calves underwent coronary artery ligations with beta-receptor blockade; hemodynamic parameters were recorded before the induction of failure, during unsupported cardiac failure, and during Hemopump and IABP support. Improvement in mean cardiac output, mixed venous oxygen saturation, and pulmonary artery wedge pressure was significantly greater (p < 0.05) during Hemopump support than during IABP support. Renal artery flow was significantly greater during Hemopump support (276 +/- 74.2 cc/min) than during IABP support (164 +/- 79.6 cc/min). Hepatic artery flow was significantly greater during Hemopump support (34.7 +/- 25.7 cc/min) than during IABP support (24.4 +/- 18.9 cc/min), and portal vein flow was significantly greater during Hemopump support (1588 +/- 315 cc/min) than IABP support (1259 +/- 310 cc/min). There were no significant differences, however, between carotid artery flow during Hemopump support (292 +/- 171 cc/min) and that during IABP support (317 +/- 204 cc/min). We conclude that renal, hepatic, and mesenteric perfusion provided by the nonpulsatile Hemopump is superior to that of the IABP in this bovine model of left ventricular failure. Therefore, the Hemopump may be more effective in preventing multiorgan failure during recovery of ventricular function.

Long-term results of the surgical management of symptomatic chronic intestinal ischemia

We analyzed our surgical experience in 20 patients who underwent revascularization procedures for symptomatic chronic intestinal ischemia caused by atherosclerosis. The group comprised 17 women and 3 men, with an age range of 25 to 71 years (mean 58.6 years). Sixteen patients had postprandial abdominal pain, and 4 had pain not related to eating. The average weight loss was 23.8 lb. Malabsorption and diarrhea were present in 8 patients. The duration of the symptoms was from 4 to 46 months (mean 13.4 months). One patient presented with acute intestinal ischemia following balloon angioplasty reocclusion of a stenotic celiac artery, and 3 underwent surgery for stenosis of a previously placed graft. Five patients had single mesenteric artery involvement, 10 had double-artery involvement, and 5 had significant occlusion in all 3 mesenteric arteries. The major arteries were revascularized whenever technically possible; therefore, 36 arteries were revascularized in 20 patients. Bypass grafts were done in 27 vessels, reimplantation in 7, and endarterectomy with patch angioplasty in 2. The saphenous vein was used in 12 vessels, polytetrafluoroethylene grafts in 8, dacron in 6, and inferior mesenteric vein in 1. The type of revascularization or graft utilized did not affect long-term patency. Two patients had early graft thrombosis and required intestinal resection. All patients survived the operation. At a mean follow-up of 36 months, all 20 patients were alive and asymptomatic with regard to their abdominal complaint. Ten patients (50%) underwent postoperative abdominal angiography; all the grafts were patent.(ABSTRACT TRUNCATED AT 250 WORDS)

Zinc fingerprinting for Phytophthora species: ZIF markers

We have assessed the potential of using zinc finger markers for identification of fungal species using Phytophthora as a model organism, since it is particularly difficult to classify. The results show that such markers are suitable for species identification of Phytophthora but do not appear to aid strain identification within species.

Implantation technique for the HeartMate left ventricular assist device

The technique for implanting the HeartMate, an intraabdominally placed, pulsatile left ventricular assist device, is described. This device, which has been developed for potential use in patients requiring permanent left ventricular assistance, is currently undergoing clinical investigation in patients requiring temporary support as they await cardiac transplantation. This clinical experience has demonstrated device safety and efficacy, even for patients requiring extended periods of support.

Reevaluation of steroid tapering after steroid pulse therapy for heart rejection

A retrospective analysis was conducted to determine the efficacy and complications resulting from steroid pulse therapy, with or without a steroid taper, in 93 episodes of heart transplant rejection that occurred in 72 patients (58 men, 14 women; mean age, 47.6 years). Each rejection episode was classified according to severity (Texas Heart Institute endomyocardial biopsy scale) and the treatment. Group 1 included 25 episodes of grade 7, 8, 9, or 10 rejection (International Society for Heart Transplantation [ISHT] grade IIIB or IV) that were treated with high-dose methylprednisolone (2.5 to 3.0 gm) and a steroid taper of 1.75 gm over 30 days. Group 2 included 16 episodes of rejection, with the severity of rejection and methylprednisolone pulse therapy being similar to that in group 1, but without a steroid taper. The results of treatment in group 1 were compared with those in group 2. Group 3 included 12 episodes of grade 5, 6, or 7 rejection (ISHT grade IIIA or IIIB) that were treated with moderate-dose methylprednisolone (1.0 to 2.0 gm) and a steroid taper, as described. Group 4 included 40 episodes of rejection, with the severity of rejection and methylprednisolone therapy being similar to that of group 3, but without a steroid taper. The results of treatment in group 3 were compared with those in group 4. No statistically significant differences were found among the groups regarding subsequent episodes of rejection or infection within 3 months of treatment. No statistically significant difference was noted among the groups in the number of rejection episodes requiring additional therapy to control the rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term results in diabetic patients undergoing heart transplantation

We conducted a retrospective study of 305 nondiabetic patients and 37 diabetic patients who underwent heart transplantation from July 1982 to May 1990. Actuarial survival was similar for both groups of patients at 1 year (76.4% versus 81.3%) and at 2 years (69.6% versus 73.0%). Because we were interested in long-term results, we further analyzed only those patients surviving more than 1 year after transplantation (214 nondiabetic patients and 29 diabetic patients). Mean follow-up for the nondiabetic patients was 31.8 +/- 16.2 months and for the diabetic patients, 32.9 +/- 4.1 months. The respective mean age in each group was 50.4 +/- 10.3 years and 51.6 +/- 9.1 years. No difference was observed between the nondiabetic patients and diabetic patients regarding the rejection rate per patient-month (0.040 +/- 0.041 versus 0.045 +/- 0.051 episodes per patient-month), the infection rate per patient-month (0.056 +/- 0.081 versus 0.081 +/- 0.102 episodes per patient-month), or renal function as evidenced by mean creatinine levels at 1, 2, and 3 years. Twelve patients were insulin-dependent before transplantation; and 1 year after transplantation, they required an insulin dose 2.12 times greater than the dose before operation. Coronary artery disease developed in 32.8% of the nondiabetic patients, compared with 31.0% of the diabetic patients by the fourth year of follow-up. Despite the need for increased insulin doses, the diabetic patients had similar long-term survival to that of the nondiabetic patients, without an increased risk of rejection, infection, renal dysfunction, or coronary artery disease. Our experience supports the feasibility of heart transplantation in selected diabetic recipients.

The effect of prolonged left ventricular support on myocardial histopathology in patients with end-stage cardiomyopathy

To determine the histopathologic effect of prolonged (> 30 days) left ventricular unloading on the myocardium, the authors studied myocardial tissue specimens from eight men (mean age, 40.8 years) with end-stage cardiomyopathy (six idiopathic, two ischemic) who were supported with the HeartMate (Thermo Cardiosystems, Inc., Woburn, MA) left ventricular assist device (LVAD) as a bridge to cardiac transplantation. The average length of support was 79.6 days (range, 31-136 days). Before left ventricular support was instituted, transthoracic echocardiography revealed that all patients had significantly dilated left ventricular cavities (average left ventricular diastolic dimension, 7.2 cm). Tissue specimens from the core of the left ventricular apex, which is removed at the time of LVAD implantation, were compared through pathologic examination with specimens from the explanted hearts at the time of cardiac transplantation. Apical core specimens from all patients exhibited extensive areas of attenuated myocardial fibers, combined with wavy patterns in some areas. In these regions, the nuclei of the cardiac myocytes from idiopathic cardiomyopathy specimens were neither pyknotic nor disappearing, as was noted in an infarcted area of a specimen from one patient with ischemic cardiomyopathy. At the time of heart transplantation, myocardial tissue specimens from the explanted hearts had a significant decrease or disappearance of stretched fibers. There was also a slight increase in interstitial replacement fibrosis, as well as an increase in the diameter of the myocardial fibers. These findings appear to correlate with the clinical impression of improved native ventricular function and with radiographic findings and decreased chamber size during prolonged ventricular support.

Leishmaniasis in a heart transplant patient

Infection is a well-recognized complication of immunosuppressive therapy. We describe a case of leishmaniasis in a 62-year-old man who was undergoing immunosuppressive therapy because of heart transplantation. A geologist and native Texan, the patient had traveled extensively in south-central Texas, but not outside of the continental United States. Cutaneous lesions of the extremities developed, which were diagnosed histologically as leishmaniasis and confirmed by means of transmission electron microscopy. Cultures grew Leishmania mexicana. Treatment with sodium antimony gluconate was successful in healing the infective lesions.

Recovery of pulmonary function in patients undergoing extended left ventricular assistance

Heart transplantation should follow the implantation of a left ventricular assist device (LVAD) only after optimal postoperative recovery of pulmonary function. We reviewed hospital records of 12 patients who underwent extended (greater than 30 days) left ventricular support before transplantation to determine the rate of return of pulmonary function. The mean cardiac index and pulmonary capillary wedge pressure returned to normal in all patients within three days after LVAD implantation. The mean pulmonary artery pressure and pulmonary vascular resistance decreased but did not return to normal. The mean central venous pressure remained elevated throughout the first month but decreased by the time of transplantation. Supplemental oxygen requirements and peak airway pressures improved, and ten of the 12 patients were extubated by the fifth postoperative day. Preoperative roentgenographic evidence of pulmonary edema was present in eight patients, and pulmonary hilar prominence was present in the remaining four patients. Roentgenographic resolution of the pulmonary edema occurred slowly, persisting for one week after surgery in seven of eight patients. Ten patients were able to exercise strenuously 30 days after surgery, and 11 were returned to excellent condition before undergoing heart transplantation. Although the hemodynamic status in these patients significantly improved shortly after LVAD implantation, optimal recovery of pulmonary function required several weeks. Therefore, we advocate delaying transplantation after LVAD implantation to allow optimal pulmonary recovery.

Human intraperitoneal response to a left ventricular assist device with a Ti-6AI-4V alloy surface

The soft tissue reaction to long-term implantation of an intraperitoneal left ventricular assist device (LVAD) was investigated. The HeartMate 1000 (Thermo Cardiosystems, Inc., Woburn, MA) is a pneumatically driven blood pump with smooth titanium alloy (Ti-6AI-4V) outer surfaces that is placed intraperitoneally in the left upper quadrant and sutured to the anterior abdominal wall. It is being used currently as a bridge to cardiac transplant, which sometimes requires extended support times. We examined the tissue capsule that formed around the rigid circular pump housing of four LVADs (duration of implant: 61, 86, 128, and 153 days) for gross, histologic, immunohistochemical, and ultrastructural analysis. Immunostaining was performed using monoclonal and polyclonal antibodies against cytoskeletal tissue markers (vimentin, desmin, alpha-smooth muscle actin), T and B lymphocytes, carcinoembryonic antigen, factor VIII, and cytokeratins (CAM 5.2 AE1/AE3, 34 beta E12, and 35 beta H11). Direct fluorescent immunolabeling for fibrinogen was also performed to characterize cell and tissue type. Histologic analysis of the 3 to 4 mm thick capsule with white, glistening inner surfaces showed fibrovascular tissue with multipotential subserosal cells (MSCs), capillary endothelium, collagen, and a few mononuclear infiltrates. The immunohistochemical profile of the MSCs differed from myofibroblasts despite a morphologic similarity. Transmission electron microscopy revealed abundant rough endoplasmic reticulum and peripherally arranged myofilaments within the spindle shaped cells. It was hypothesized that capsule formation was initiated by fibrin deposition, followed by proliferation of MSCs and subsequent formation of fibrovascular tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful bridge to heart transplantation with a new left ventricular assist device

During the last 5 years, a new pneumatically driven left ventricular assist device has been implanted in 18 heart transplantation candidates who required advanced mechanical circulatory support. The mean duration of support was 80 +/- 74 days, and the cumulative support time was 1400 days. Fifteen patients were successfully supported until the time of heart transplantation. As a result of early experience, in which three of four patients died after heart transplantation because their end-organ function failed to recover, subsequent efforts were made to institute support early, before irreversible organ damage occurred. Eleven of the 12 patients in the later experience are currently alive and well at a mean follow-up of 12.6 +/- 7.5 months. No thromboembolic episodes occurred, and minimal anticoagulation was required. Furthermore, patients were able to participate in rehabilitative exercise programs, thus optimizing their transplantation status. Finally, the findings in these patients have shown the feasibility of providing long-term, or even permanent, cardiac assistance.

Bacterial mediastinitis after heart transplantation

Bacterial mediastinal abscess or mediastinitis developed in nine (2.5%) of 361 consecutive patients who underwent isolated heart transplantation at the Texas Heart Institute. All nine patients had at least one predisposing factor that may have contributed to the development of mediastinitis. These included insulin-dependent diabetes mellitus, repeat operation for postoperative mediastinal hemorrhage, Staphylococcus aureus pneumonitis, and cardiac allograft rejection in the early postoperative period (less than 30 days), necessitating steroid pulse therapy alone or in combination with murine-derived monoclonal antibody (OKT3). In six of the nine patients, the diagnosis of mediastinitis was made on the basis of clinical findings (unstable sternum and incisional erythema, with or without gross purulence), and in the other three patients, diagnosis was confirmed by computed tomography of the chest. Culture data were unequivocal in all patients; S. aureus was the most frequent (five patients), followed by S. epidermidis (two patients), and Enterobacter cloacae (two patients). Computed tomography-directed percutaneous drainage and systemic antibiotics were successful in treating two of three patients who had stable sternums with mediastinal abscess. In the remaining seven patients, sternal and mediastinal debridement with rewiring of the sternum was successfully applied. No patient required muscle or omental flap coverage, and no patient experienced a recurrence of mediastinitis during an average follow-up period of 35 months (range, 12 to 46 months).

Intracavitary repair of ventricular aneurysm and regional dyskinesia

Myocardial damage after infarction is a common sequela in patients with coronary occlusive disease. The extent of injury varies and may be localized or diffuse. Since March 1989, the authors have used a new surgical repair technique that employs an intracavitary patch of Dacron fabric or glutaraldehyde-treated pericardium to exclude the hypokinetic or fibrotic myocardial segment. An elliptical configuration preserves the contour and volume of the ventricular cavity. After securing the patch, the ventriculotomy is closed with a simple continuous suture. Through July 31, 1991, 136 patients underwent repair using this technique. Of these patients, 100 (group I) had neither sustained an acute myocardial infarction (within 30 days before surgery) nor had undergone previous cardiac surgery, whereas 36 (group II) had sustained an acute myocardial infarction or had undergone previous cardiac surgery. In group I, four (4%) died within 30 days of surgery, and seven died later, resulting in a 6-month survival of 90.5% and a 1-year survival of 85.3%. In group II, 11 (30.6%) died within 30 days of surgery, and three died later. Functional class improved after repair in 95.7% of patients in group I and all patients in group II. In both groups, ejection fraction improved significantly (p less than 0.0001, group I; p less than 0.0001, group II). By eliminating the need for epicardial buttresses to repair the ventriculotomy, myocardial revascularization has been possible in most patients. This method of intraventricular repair is also appropriate for patients with calcified aneurysms, acquired ventricular septal defects, and acute ventricular rupture.

Heart transplantation after mechanical circulatory support: four years' experience

To determine the effect of mechanical circulatory support before heart transplantation, we conducted a retrospective analysis of 207 men who underwent staged orthotopic transplantations. Of these patients, 185 (group I) required pharmacologic support before transplantation; 14 (group II) required mechanical circulatory support with an intraaortic balloon pump (duration of support, 1 to 26 days); and eight (group III) required advanced mechanical circulatory support with an implantable left ventricular assist device (duration of support, 19 to 132 days). A comparison of complications after transplantation (infection and rejection), hospitalization, and survival showed that no significant differences existed among the three groups. In each group, respectively, 1-year survival was 80.9%, 77.3%, and 75%, and 2-year survival was 75.7%, 67.7%, and 75%. Based on our experience, patients receiving mechanical circulatory support before transplantation can be expected to have a good outcome. In fact, such support can help to improve their end-organ perfusion, and, thus, their status as heart transplantation candidates. Furthermore, this study shows that advanced mechanical circulatory support is possible even for prolonged periods, with low risk of sudden death. This finding is an important step toward development of a permanent assist device.

Preoperative and postoperative Hemopump support for patients undergoing orthotopic heart transplantation

The Hemopump (Johnson & Johnson Interventional Systems, Rancho Cordova, CA) can be used successfully as a bridge to cardiac transplantation in patients with advanced cardiogenic shock that proves to be irreversible. Some patients, however, may also benefit from maintaining Hemopump support for a period of time after transplantation. A technique has been developed for continuing Hemopump support after transplantation that does not require repositioning of the device.

Clinical evaluation of right ventricular function in patients with left ventricular assist device (LVAD)

Right ventricular function (RVF) during LVAD support can be a threat for patient survival. Despite extensive research, RVF and its interference with left heart function is unclear. This study examines RVF in a retrospective analysis of 14 patients. Hemodynamic data were collected, including heart rate (HR), central venous pressure (CVP), mean pulmonary artery pressure (mPAP), total cardiac output (CO), calculated stroke volume index (SVI) and right ventricular stroke work index (RVSWI). In all patients, CO increased gradually throughout the study period; CVP showed no significant decrease; mPAP and PCWP decreased significantly over the time period; SVI improved and RVSWI increased from the starting level prior to implantation of the LVAD. We conclude that the CO improved with a lowering of the right ventricular afterload combined with a decrease in total circulating volume. The improvement of RVF with LV assist makes this device an option as a bridge to transplant.