Estimating Loss of Brucella Abortus Antibodies from Age-Specific Serological Data In Elk

Serological data are one of the primary sources of information for disease monitoring in wildlife. However, the duration of the seropositive status of exposed individuals is almost always unknown for many free-ranging host species. Directly estimating rates of antibody loss typically requires difficult longitudinal sampling of individuals following seroconversion. Instead, we propose a Bayesian statistical approach linking age and serological data to a mechanistic epidemiological model to infer brucellosis infection, the probability of antibody loss, and recovery rates of elk (Cervus canadensis) in the Greater Yellowstone Ecosystem. We found that seroprevalence declined above the age of ten, with no evidence of disease-induced mortality. The probability of antibody loss was estimated to be 0.70 per year after a five-year period of seropositivity and the basic reproduction number for brucellosis to 2.13. Our results suggest that individuals are unlikely to become re-infected because models with this mechanism were unable to reproduce a significant decline in seroprevalence in older individuals. This study highlights the possible implications of antibody loss, which could bias our estimation of critical epidemiological parameters for wildlife disease management based on serological data.

Probable causes of increasing brucellosis in free-ranging elk of the Greater Yellowstone Ecosystem

While many wildlife species are threatened, some populations have recovered from previous overexploitation, and data linking these population increases with disease dynamics are limited. We present data suggesting that free-ranging elk (Cervus elaphus) are a maintenance host for Brucella abortus in new areas of the Greater Yellowstone Ecosystem (GYE). Brucellosis seroprevalence in free-ranging elk increased from 0-7% in 1991-1992 to 8-20% in 2006-2007 in four of six herd units around the GYE. These levels of brucellosis are comparable to some herd units where elk are artificially aggregated on supplemental feeding grounds. There are several possible mechanisms for this increase that we evaluated using statistical and population modeling approaches. Simulations of an age-structured population model suggest that the observed levels of seroprevalence are unlikely to be sustained by dispersal from supplemental feeding areas with relatively high seroprevalence or an older age structure. Increases in brucellosis seroprevalence and the total elk population size in areas with feeding grounds have not been statistically detectable. Meanwhile, the rate of seroprevalence increase outside the feeding grounds was related to the population size and density of each herd unit. Therefore, the data suggest that enhanced elk-to-elk transmission in free-ranging populations may be occurring due to larger winter elk aggregations. Elk populations inside and outside of the GYE that traditionally did not maintain brucellosis may now be at risk due to recent population increases. In particular, some neighboring populations of Montana elk were 5-9 times larger in 2007 than in the 1970s, with some aggregations comparable to the Wyoming feeding-ground populations. Addressing the unintended consequences of these increasing populations is complicated by limited hunter access to private lands, which places many ungulate populations out of administrative control. Agency-landowner hunting access partnerships and the protection of large predators are two management strategies that may be used to target high ungulate densities in private refuges and reduce the current and future burden of disease.

Real time patient safety audits: improving safety every day

BACKGROUND

Timely error detection including feedback to clinical staff is a prerequisite for focused improvement in patient safety. Real time auditing, the efficacy of which has been repeatedly demonstrated in industry, has not been used previously to evaluate patient safety. Methods successful at improving quality and safety in industry may provide avenues for improvement in patient safety.

OBJECTIVE

Pilot study to determine the feasibility and utility of real time safety auditing during routine clinical work in an intensive care unit (ICU).

METHODS

A 36 item patient safety checklist was developed via a modified Delphi technique. The checklist focused on errors associated with delays in care, equipment failure, diagnostic studies, information transfer and non-compliance with hospital policy. Safety audits were performed using the checklist during and after morning work rounds thrice weekly during the 5 week study period from January to March 2003.

RESULTS

A total of 338 errors were detected; 27 (75%) of the 36 items on the checklist detected >or=1 error. Diverse error types were found including unlabeled medication at the bedside (n = 31), ID band missing or in an inappropriate location (n = 70), inappropriate pulse oximeter alarm setting (n = 22), and delay in communication/information transfer that led to a delay in appropriate care (n = 4).

CONCLUSIONS

Real time safety audits performed during routine work can detect a broad range of errors. Significant safety problems were detected promptly, leading to rapid changes in policy and practice. Staff acceptance was facilitated by fostering a blame free "culture of patient safety" involving clinical personnel in detection of remediable gaps in performance, and limiting the burden of data collection.

Topical ointment for preventing infection in preterm infants

BACKGROUND

Nosocomial sepsis is a frequent and serious complication of premature infants. The increased susceptibility of ELBW infants to infection has been attributed to less effective immune function compared to mature newborns and the invasive nature of necessary supportive care. Breakdown of the barrier function of the skin may be an additional risk factor for nosocomial sepsis.

OBJECTIVES

To assess the effect of prophylactic application of topical ointment on nosocomial sepsis rates and other complications of prematurity in preterm infants.

SEARCH STRATEGY

Searches were made of the Cochrane Central Registry of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2003), Ovid DC MEDLINE through June 2003, previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants, and journal hand searching in the English language.

SELECTION CRITERIA

Randomized controlled trials which compared the effect of prophylactic application of topical ointment to routine (standard) skin care or as needed topical therapy in preterm infants are included in this review.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including infection [including any bacterial infection, bacterial infection with a known pathogen, coagulase negative staphylococcal infection, fungal infection, and any nosocomial infection (bacterial or fungal)], patent ductus arteriosus, oxygen requirement at 28 days, chronic lung disease and mortality were excerpted from the reports of the clinical trials by the reviewers. Data analysis was done in accordance with the standards of the Cochrane Neonatal Review Group.

MAIN RESULTS

Four randomized controlled trials were identified. All four studies reported improved skin condition in infants treated with prophylactic topical ointment (results not reported here). All four studies reported on the incidence of any nosocomial infection, fungal infection and coagulase negative staphylococcal infection. Infants treated with prophylactic topical ointment are at increased risk of coagulase negative staphylococcal infection (typical relative risk 1.31, 95% CI 1.02, 1.70; typical risk difference 0.04, 95% CI 0.00, 0.08); and any nosocomial infection (typical relative risk 1.20, 95% CI 1.00, 1.43; typical risk difference 0.05, 95% CI 0.00, 0.09). A trend toward increased risk of any bacterial infection was found in infants treated with prophylactic topical ointment (typical relative risk 1.19, 95% CI 0.97, 1.46; typical risk difference 0.04, 95% CI -0.01, 0.08). There was no significant difference found in the risk of bacterial infection with a known pathogen, fungal infection, or other complications related to prematurity.

REVIEWER'S CONCLUSIONS

Prophylactic application of topical ointment increases the risk of coagulase negative staphylococcal infection and any nosocomial infection. A trend toward increased risk of any bacterial infection was noted in infants prophylactically treated. Topical ointment should not be used routinely in preterm infants.

Hb Dartmouth [alpha66(E15)Leu-->Pro (alpha2) (CTG-->CCG)]: a novel alpha2-globin gene mutation associated with severe neonatal anemia when inherited in trans with Southeast Asian alpha-thalassemia-1

We report a novel mutation at alpha66(E15)Leu-->Pro (alpha2) (CTG-->CCG), that we have named Hb Dartmouth for the medical center at which the patients were cared for, in monozygotic twins who also inherited the Southeast Asian alpha-thalassemia-1 deletion. The mother, of Khmer ancestry, is heterozygous for alpha-thalassemia-1. The father, who is of Scottish-Irish ancestry, is a silent carrier of the codon 66 mutation. The twins had severe neonatal anemia requiring transfusion.

Lymphangiomatosis and massive osteolysis of the cervical spine. A case report and review of the literature

On the basis of clinical, radiographic, and pathologic evidence, massive osteolysis can be divided into two forms: Gorham's disease and angiomatosis. The present case is the first report of massive osteolysis of the lymphangiomatosis type involving the cervical spine but without visceral involvement. Originally, plain lymphangiomatosis was diagnosed, but the diagnosis was changed to massive osteolysis. Only one other case of lymphangiomatosis with cervical involvement was found, but in that case the viscera were also involved. Both cases exemplify a prolonged progressive pattern, recalcitrant to treatment and with a devastating outcome. Diagnosis by biopsy is difficult, and incremental radiation therapy early in the disease process should be considered.

Economic implications of neonatal intensive care unit collaborative quality improvement

OBJECTIVE

To make measurable improvements in the quality and cost of neonatal intensive care using a multidisciplinary collaborative quality improvement model.

DESIGN

Interventional study. Data on treatment costs were collected for infants with birth weight 501 to 1500 g for the period of January 1, 1994 to December 31, 1997. Data on resources expended by hospitals to conduct this project were collected in a survey for the period January 1, 1995 to December 31, 1996.

SETTING

Ten self-selected neonatal intensive care units (NICUs) received the intervention. They formed 2 subgroups (6 NICUs working on infection, 4 NICUs working on chronic lung disease). Nine other NICUs served as a contemporaneous comparison group.

PATIENTS

Infants with birth weight 501 to 1500 g born at or admitted within 28 days of birth between 1994 and 1997 to the 6 study NICUs in the infection group (N = 2993) and the 9 comparison NICUs (N = 2203); infants with birth weight 501 to 1000 g at the 4 study NICUs in the chronic lung disease group (N = 663) and the 9 comparison NICUs (N = 1007).

INTERVENTIONS

NICUs formed multidisciplinary teams which worked together to undertake a collaborative quality improvement effort between January 1995 and December 1996. They received instruction in quality improvement, reviewed performance data, identified common improvement goals, and implemented "potentially better practices" developed through analysis of the processes of care, literature review, and site visits.

MAIN OUTCOME MEASURES

Treatment cost per infant is the primary economic outcome measure. In addition, the resources spent by hospitals in undertaking the collaborative quality improvement effort were determined.

RESULTS

Between 1994 and 1996, the median treatment cost per infant with birth weight 501 to 1500 g at the 6 project NICUs in the infection group decreased from $57 606 to $46 674 (a statistical decline); at the 4 chronic lung disease hospitals, for infants with birth weights 501 to 1000 g, it decreased from $85 959 to $77 250. Treatment costs at hospitals in the control group rose over the same period. There was heterogeneity in the effects among the NICUs in both project groups. Cost savings were maintained in the year following the intervention. On average, hospitals spent $68 206 in resources to undertake the collaborative quality improvement effort between 1995 and 1996. Two thirds of these costs were incurred in the first year, with the remaining third in the second year. The average savings per hospital in patient care costs for very low birth weight infants in the infection group was $2.3 million in the post-intervention year (1996). There was considerable heterogeneity in the cost savings across hospitals associated with participation in the collaborative quality improvement project.

CONCLUSION

Cost savings may be achieved as a result of collaborative quality improvement efforts and when they occur, they appear to be sustainable, at least in the short run. In high-cost patient populations, such as infants with very low birth weights, cost savings can quickly offset institutional expenditures for quality improvement efforts.

Collaborative quality improvement for neonatal intensive care. NIC/Q Project Investigators of the Vermont Oxford Network

OBJECTIVE

To make measurable improvements in the quality and cost of neonatal intensive care using a multidisciplinary collaborative quality improvement model.

DESIGN

Interventional study. Patient demographic and clinical information for infants with birth weight 501 to 1500 g was collected using the Vermont Oxford Network Database for January 1, 1994 to December 31, 1997.

SETTING

Ten self-selected neonatal intensive care units (NICUs) received the intervention. They formed 2 subgroups (6 NICUs working on infection, 4 NICUs working on chronic lung disease). Sixty-six other NICUs served as a contemporaneous comparison group.

PATIENTS

Infants with birth weight 501 to 1500 g born at or admitted within 28 days of birth between 1994 and 1997 to the 6 study NICUs in the infection group (n = 3063) and the 66 comparison NICUs (n = 21 509); infants with birth weight 501 to 1000 g at the 4 study NICUs in the chronic lung disease group (n = 738).

INTERVENTIONS

NICUs formed multidisciplinary teams that worked together under the direction of a trained facilitator over a 3-year period beginning in January 1995. They received instruction in quality improvement, reviewed performance data, identified common improvement goals, and implemented "potentially better practices" developed through analysis of the processes of care, literature review, and site visits.

MAIN OUTCOME MEASURES

The rates of infection after the third day of life with coagulase-negative staphylococcal or other bacterial pathogens for infants with birth weight 501 to 1500 g, and the rates of oxygen supplementation or death at 36 weeks' adjusted gestational age for infants with birth weight 501 to 1000 g.

RESULTS

Between 1994 and 1996, the rate of infection with coagulase-negative staphylococcus decreased from 22.0% to 16.6% at the 6 project NICUs in the infection group; the rate of supplemental oxygen at 36 weeks' adjusted gestational age decreased from 43.5% to 31.5% at the 4 NICUs in the chronic lung disease group. There was heterogeneity in the effects among the NICUs in both project groups. The changes observed at the project NICUs for these outcomes were significantly larger than those observed at the 66 comparison NICUs over the 4-year period from 1994 to 1997.

CONCLUSION

We conclude that multidisciplinary collaborative quality improvement has the potential to improve the outcomes of neonatal intensive care.

Vertebral-carotid transposition

In the early years of evaluating patients with cerebral disease, the origins of the vertebral and subclavian arteries were not routinely visualized. Surgical intervention was more formidable then, and most symptoms were thought to be relieved by corrective carotid surgery. The continued occurrence of nonhemispheric symptoms in some patients, coupled with better techniques of diagnosis and improved surgical techniques, prompted the complete angiographic evaluation of total cerebral flow in all patients evaluated for cerebral symptoms. When carotid endarterectomy did not relieve hind brain symptoms, whether there was significant decreased vertebral flow, and whether surgical was indicated, could then be determined. Most vertebral artery occlusive disease is located near its origin and can be relieved by vertebral carotid transposition. The operative technique is described in this article along with pertinent anatomy and historical perspectives.

Emollient ointment for preventing infection in preterm infants

BACKGROUND

This section is under preparation and will be included in the next issue.

OBJECTIVES

To assess the effect of prophylactic application of emollient ointment in preterm infants.

SEARCH STRATEGY

Searches were made of the Oxford Database of Perinatal Trials, Medline (MeSH terms: ointment; limits: age groups, newborn infant; publication types, clinical trial), previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants, and journal handsearching in the English language.

SELECTION CRITERIA

Randomized controlled trials which compared the effect of prophylactic application of emollient ointment to routine care or as needed topical therapy in preterm infants are included in this review.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including transepidermal water loss, skin condition, fluid intake, suspect infection and proven nosocomial infection were excerpted from the reports of the clinical trials by the reviewers. Data analysis was done in accordance with the standards of the Cochrane Neonatal Review Group.

MAIN RESULTS

Two randomized trials which compared prophylactic application of ointment to routine skin care or as needed topical ointment therapy were identified. Lane (1993) noted improved skin condition in infants receiving topical application of emollient ointment. In the study of Nopper and coworkers (1996), prophylactic application of ointment significantly decreased transepidermal water loss during the first six hours after initial application. Skin condition was noted to be improved during the first 1-2 weeks. Surveillance cultures demonstrated less bacterial colonization during the two week study. A significant decrease in suspect and proven infection was noted. Fewer infants were evaluated for sepsis among the group who received prophylactic application of ointment (relative risk 0. 50, 95% CI 0.27, 0.93; risk difference -0.30, 95% CI -0.54, -0.06). Both studies reported on the incidence of proven nosocomial infection. A trend towards a decrease in the risk of proven nosocomial infection was noted in infants who received prophylactic application of emollient ointment (typical relative risk 0.29, 95% CI 0.07, 1.16, typical risk difference -0.13, 95% CI -0.25, -0.01).

REVIEWER'S CONCLUSIONS

In two small studies, prophylactic application of emollient ointment decreased transepidermal water loss, decreased the severity of dermatitis, and decreased the risk of suspect sepsis and proven sepsis. Further clinical studies are warranted to validate these results.

Bifurcated devices in the treatment of abdominal aortic aneurysms: limitations and advantages of a single-component bifurcated prosthesis

Currently, prostheses for endovascular repair of abdominal aortic aneurysms are divided into 2 device categories. Endoprostheses based on the first approach arise from the concept that endovascular grafting should ideally mimic standard surgical repair of abdominal aortic aneurysms. The second category of devices developed from a design strategy that was a conceptual outgrowth of transcathete-based techniques in which an endovascular graft is constructed de novo within the abdominal aorta from modular components. Both grafts are dependent on the successful exclusion of blood flow from the aneurysm sac. Ongoing clinical trials of these 2 categories of devices have yet to be completed with long-term data, but it is apparent even at this early stage that there exist both advantages and limitations to each system. In this review, these issues are discussed for single-component bifurcated endografts within the context of our 5-year experience gained through the use of a bifurcated device produced by Endovascular Technologies, Inc (EVT). Overall, present limitations of the single-component bifurcated prosthesis are related to graft size and the somewhat cumbersome maneuvers required for implantation. Nonetheless, the inherent advantages of these prostheses, including their durability and capacity to respond to aneurysm remodeling without late device failure, may ultimately provide the patient with a prosthesis with superior long-term clinical performance characteristics.

An assessment of the current applicability of the EVT endovascular graft for treatment of patients with an infrarenal abdominal aortic aneurysm

OBJECTIVE

To determine the percentage of elective abdominal aortic aneurysms (AAAs)/aortoiliac aneurysms that currently can be repaired with endovascular grafts (EVGs), the reasons for rejection of EVGs, and the future role of EVG in the treatment of AAA.

METHODS

From January 1997 to May 1998, patients at three hospitals (a university hospital, a university-affiliated teaching hospital, and a Veterans Administration hospital with university faculty and residents) were evaluated for EVGs as part of a national clinical trial with grafts manufactured by Endovascular Technologies (EVT, Menlo Park, Calif). All patients at two hospitals and patients treated by the participating surgeons at the third hospital were screened for EVG. Patients with AAAs that were ruptured, symptomatic, or involved renal or mesenteric arteries and patients who declined treatment were excluded from the study. Evaluation included clinical examination, computed tomography scan, and selective arteriography. The decision to proceed with EVG was made by the vascular surgeon, with input and concurrence of medical personnel from a company with extensive experience in endograft repair. The main outcome measures were the determination of the percentage of elective AAAs currently being treated with an EVG and the reasons for exclusion of patients from EVG placement.

RESULTS

A total of 162 patients underwent elective treatment of an AAA, 22 (14%) with an EVG (14 bifurcated, eight tube) and 140 (86%) with traditional resection. Indications for not proceeding with an EVG included insufficient proximal cuff in 29 patients (21%), distal common iliac aneurysm or insufficient distal iliac neck in 29 patients (21%), proximal neck too large for an EVG in 24 patients (17%), symptomatic iliac stenosis in 23 patients (16%), iliac stenosis precluding introducer passage in 17 patients (12%), patient preference in 11 patients (8%), and calcification, kink, or extensive thrombus involving the proximal neck precluding safe graft attachment in seven patients (5%). Of the 22 patients treated with an EVG, three were converted to open resection, because of iliac stenosis in two patients and premature stent deployment in one patient (initial technical success rate, 86%).

CONCLUSION

Based on currently available technology, 80% of patients were not candidates for an EVG because of proximal calcification, short aortic or distal cuff, coexisting distal iliac aneurysm, and stenotic iliac disease. Even with the use of adjunctive procedures, most patients still require open repair. Significant changes in design will be necessary to apply these devices to most patients with an AAA.

The New Hampshire Perinatal Program: twenty years of perinatal outreach education

OBJECTIVE

To describe 20 years of regional outreach education by the New Hampshire Perinatal Program, its interaction with all 26 community hospitals in the state with maternity services and an additional four in adjoining Vermont.

STUDY DESIGN

This paper describes educational initiatives responsive to the needs of perinatal physicians and nurses. The core of the program is the transport conference held annually at each referring hospital in which maternal-fetal and infant referrals are discussed. There are additional community hospital-based programs, programs at convenient locations in the region and medical center conferences and skills programs.

RESULTS

The program annually awards 10,000 continuing medical education credits (CME) and nursing contact hours. Evaluation and feedback from all participants is encouraged. New Hampshire has one of the lowest perinatal mortality rates in the county, which reflects in part the accomplishments of the program.

CONCLUSION

Perinatal outreach education is a shared responsibility of providers in both the academic center and community hospitals and is necessary to ensure optimal care for mothers and infants.

Management of neuropathic fractures in the foot and ankle

Neuroarthropathy, a rapid, painless destructive process, has become increasingly prevalent among long-lived diabetic patients. It is characterized by warm, swollen joints with a grossly disorganized radiographic appearance, in spite of which the patient is often pain-free. Neglect of this condition results in progressive deformity or instability, often complicated by ulceration and infection, which can ultimately result in loss of independent mobility, loss of the affected limb, and even death. In most cases, a plantigrade, stable, and functional foot can be achieved with simple nonoperative techniques, such as the use of a total-contact cast or shoe modification. A few patients in whom uncontrolled instability or major osseous prominences cause recurrent ulceration will require reconstructive surgery (either exostectomy or osteotomy/arthrodesis). Although some patients will have an improvement in function, ongoing vigilance is necessary.

Technical complications of endovascular abdominal aortic aneurysm repair

PURPOSE

Results from 34 endovascular repairs of abdominal aortic aneurysms are reviewed to identify technical complications and relate them to anatomic and technical features of the operation.

METHODS

Twenty-one patients underwent attempted tube graft repair (mean follow-up, 13 months). Thirteen patients underwent placement of a bifurcated graft (mean follow-up, 7.2 months).

RESULTS

Twenty-five patients (74%) underwent repair without technical complication (16 tube graft and nine bifurcated graft). Of five patients who had tube graft complications, two involved small iliac arteries and resulted in arterial injury. One of these patients needed a femorofemoral bypass procedure, and the other required conversion to standard operation. Two patients had distal leaks associated with the attachment system, and one patient had misplacement of the distal attachment system. The two patients who had leaks were followed-up; one required operation after 7 months, whereas the other leak sealed. The patient who had distal attachment system misplacement had a second endograft placed within the first to provide a distal seal. The four patients who had bifurcated graft complications involved two graft limb stenoses, one managed with a Palmaz stent and the other with balloon angioplasty. The patient treated with balloon angioplasty had graft thrombosis 1 week after the operation, which resulted in the need for a femorofemoral bypass procedure. Another bifurcated graft patient had a graft limb twist, which has resulted in chronic claudication. One patient had placement of a limb too proximal in the common iliac artery with chronic leak, and an open operation was performed 18 months later.

CONCLUSIONS

Technical complications in this series seem to be associated with short distal necks, small iliac arteries, tortuous iliac arteries, and atherosclerosis at the aortic bifurcation. We believe that experience and understanding of these issues will reduce the risk of these complications in the future.

Limb ischemia: surgical therapy in acute arterial occlusion

Mortality and amputation rates from acute arterial occlusion are reported from 7 to 37 per cent and 10 to 30 per cent, respectively. Recent data from thrombolysis or peripheral arterial surgery suggest no significant differences between initial management with surgical or thrombolytic therapy. Mortality and amputation rates were in the above ranges. The last 230 procedures (216 patients) over 10 years were reviewed. All graft occlusions, cardiac catheterization injuries, and aortic balloon-related thromboses were excluded. Immediate and delayed amputation rates were 6.5 and 0.9 per cent. Death occurred in 21 patients (9.7%), with only 6 deaths over the last 6 years (3.8%). Except for transesophageal echocardiography, perioperative studies were of limited value. Long-term anticoagulation was also not effective in preventing recurrent episodes. A mortality rate of 9.7 per cent and amputation rate of 7.4 per cent justifies an early aggressive surgical approach. Limited perioperative studies and less prolonged anticoagulation may also improve cost containment.

Resource utilization and pathways: meeting the challenge of cost containment

The 1990s will bring sweeping changes with managed care and capitation. To address this cost/quality paradox, selective intensive care utilization is coupled with clinical pathways as an innovative change for all patients having cerebral revascularization (CVR) or femoral revascularization (FR). From January 1, 1991 through June 30, 1995, data were accumulated on 2023 procedures in 1524 patients. The study was based on 848 CVRs and 1175 FRs. Intensive care unit (ICU) observation was necessary in 73 patients (3.6%) for cardiac or hypertensive management. Twenty-six patients (1.2%) transported to a vascular surgical floor from the postanesthesia recovery room required return to an ICU for complications during hospitalization. There were nine strokes or transient ischemic attacks (0.4%) in the CVR group, four myocardial infarctions (0.2%), and five perioperative deaths (0.3%). In the FR group, there were 14 deaths (0.9%). Readmission during the perioperative period, 30 days, was necessary in 46 patients (3.1%). Financial cost analysis revealed the mean adjusted cost for CVR in 1990 adjusted to 1995 dollars was $7223. The institution of case management reduced this to $4490 (37.8 per cent reduction in total hospital costs). The cost for FR in 1990 dollars adjusted to 1995 was $14,332 reduced to $5541 (a 59 per cent reduction in total hospital costs). This study suggests the use of clinical pathways does not impair quality of care, leads to no higher morbidity or mortality, and can produce significant cost savings to a hospital.

Evaluation of the neonatal nurse practitioner role: the next frontier

The neonatal nurse practitioner (NNP) role at Dartmouth Hitchcock Medical Center in Lebanon, New Hampshire, has been in place since 1989. As part of the professional growth and development of this NNP group, the necessity for a useful evaluation instrument emerged. This instrument needed to be congruent with the job description, practice philosophy, and strong commitment to peer review. The literature search and institutional survey failed to uncover an acceptable option, so an evaluation instrument was developed, tested, and refined. This instrument captures the diverse scope of NNP practice and incorporates a continuum of novice to expert competencies based on the work of Patricia Benner. This evaluation mechanism has had a profound effect on our group, encouraging the development of a shared vision of the NNP role and stimulating professional growth.

Endovascular grafting of abdominal aortic aneurysms. A preliminary study

OBJECTIVE

The authors report the experience of a single investigational center involving two Phase I and a Phase II clinical trials approved by the Food and Drug Administration (FDA) for the transfemoral implantation of woven Dacron grafts for abdominal aortic aneurysms.

SUMMARY BACKGROUND DATA

In 1993, EndoVascular Technologies, Inc. ([EVT]; Menlo Park, CA), began an FDA-approved clinical trial of repair of abdominal aortic aneurysms by transfemoral placement of a tube endograft. Subsequently, a bifurcated endograft trial was started. This the first single institution report using the EVT endograft for both tube and bifurcated aortic replacement.

METHODS

Seventeen patients were enrolled in two Phase I and one Phase II clinical trials. The Phase I tube graft trial and the Phase I bifurcated graft trial were nonrandomized studies. The Phase II tube graft trial consisted of a randomized prospective control trial of open endoaneurysmorrhaphy versus transfemoral placement of an endograft.

RESULTS

Seventeen patients were enrolled in the trial. The graft was placed successfully in all but one patient. Five patients randomized to open procedure and one declined to participate. Eleven patients with endografts are available for follow-up. One graft has been explanted for attachment system migration. One patient is a late failure because of persistent filling of the aneurysm sac.

CONCLUSION

Transfemoral placement of an endovascular graft is a viable and effective treatment of abdominal aortic aneurysms in the short term. Use of a bifurcated endograft will open the procedure to more patients. The ideal attachment system and graft material await long-term implantation follow-up.

An unsuspected cause for recurrent angina: subclavian artery stenosis

The advantages of internal mammary artery (IMA) grafts over saphenous vein grafts (SVG) for coronary artery bypass grafting have been extensively recorded in the literature. Operative results and postoperative mortality in patients with IMA versus SVG are comparable. The relative risks of thrombosis, however, of an SVG are four to five times greater than an IMA graft, and the probability of recurrent angina or need for reoperation is significantly less in IMA grafted patients. Coltharp et al. also showed that the risks of reoperation for recurrent angina were decreased by a previously constructed IMA graft.

Preliminary experience with the Endovascular Technologies bifurcated endovascular aortic prosthesis in a calf model

PURPOSE

The purpose of this study was to develop a bifurcated endoluminal prosthesis for transfemoral placement in the aortoiliac position with a large-animal model that would simulate human implantation.

METHODS

Fifteen calves (160 to 200 kg) underwent bilateral femoral artery exposure and transfemoral placement in the aortoiliac position of a bifurcated Dacron prosthesis, inserted through a 26F sheath with an over-the-bifurcation guide wire to retrieve the contralateral limb and secured proximally and distally with self-expanding attachment systems. The preferred location was determined before implantation and compared with final implant location by caliper measurements and angiography. Events during implantation, maneuvers used to accomplish accurate deployment, and final results, as judged by angiography and clinical evaluation, were recorded. Four animals survived and were used for chronic evaluation and healing by gross and microscopic studies.

RESULTS

All grafts (n = 15) were patent at the end of the procedure. All (n = 7) noncrimped grafts had minor kinks in areas of curvature, whereas eight of eight crimped grafts (device modification) had none. Torque control of the body and individual limbs was necessary to correct twists before deployment in 10 of 15 grafts, with two greater than 30-degree twists remaining, which did not appear to affect flow. One implant was entirely deployed in the aorta because of parallax error, subsequently avoided by use of a marker board placed dorsally. Three premature deployments occurred, corrected by attachment system lock modification. The mean final implant position was within 2.9 +/- 1.4 mm (aortic), 1.6 +/- 1.1 mm, and 1.5 +/- 0.8 mm (contralateral and ipsilateral iliac limbs, respectively) of the intended position. Three of four animals intended for long-term evaluation were killed prematurely because of clinically evident spinal cord ischemia. Histologic sections at 2 weeks showed early wall repair without inflammatory cells and pannus ingrowth across the anastomosis.

CONCLUSION

We conclude that implantation of a bifurcated endovascular prosthesis through the bilateral femoral approach is possible, provided the intended aortic implantation site (neck) is at least 12 mm in length (mean +/- 2 SD each direction). Torque control of each portion of the device will be needed in the majority of instances, with attention to parallax effect necessary for optimal placement. This animal model is not suitable for chronic graft evaluation because of its sensitivity for spinal cord ischemia. Healing data suggest graft incorporation similar to that of a surgically placed prosthesis.

Effects of vesicocolic anastomosis on the proliferation of colonic mucosa in a rat model

The effects of diverting the urinary stream into a defunctioned segment of the distal colon has been studied in a rat model. Distal rat colon was defunctioned using the Hartmann's procedure and a vesicocolic anastomosis was performed 14 days later. The distal colon was harvested after 10 days following the administration of a vinblastine mitotic block either 1 or 3 h before death. Both the mean crypt cell proliferation and the crypt length were increased significantly in the colonic mucosa exposed to urine when compared with the control defunctioned colon or to the functional unexposed proximal colon. An active fraction was obtained from human urine by elution from a diethylaminoethyl sepharose column using 1 mol/L NaCl. This fraction was administered intraluminally to defunctioned rat colons using Alzet minosmotic pumps. In these animals the crypt cell production rate was significantly increased compared with the control animals. Although the crypt length did not increase significantly in these animals the atrophy normally seen in defunctioned colonic mucosa did not occur. The identity of the active molecule in this urine fraction is still being determined.

Case management in cerebral revascularization

PURPOSE

We examined the clinical and financial outcomes of case management coupled with the initiation of selective use of the intensive care unit (ICU) in all cerebral revascularization procedures.

METHODS

Three hundred eighty-four procedures in 331 patients were retrospectively reviewed. Morbidity and mortality rates, hospital length of stay, cost, and ICU or hospital readmissions were examined. Hypertension was examined as an independent variable for its effect on patient outcome.

RESULTS

Cerebral revascularization, including carotid endarterectomy, vertebral-carotid artery transposition, and subclavian-carotid artery transposition, yielded a 0.78% stroke rate and 0.26% perioperative death rate in this series. ICU admission was necessary in nine patients (2.3%) for cardiac or respiratory instability. Three patients (0.78%) required transfer to the ICU for management of hypertension or hypotension. The mean hospital length of stay after institution of case management was reduced by 2.1 days, and the mean cost was decreased by $1987, a savings of 28.9% of total hospital cost.

CONCLUSION

The dual approach of case management and selective use of the ICU promotes quality patient care, conserves financial resources without adversely affecting morbidity or mortality rates, enhances physician/nurse collaboration, and improves patient satisfaction.

Subclavian revascularization. A quarter century experience

OBJECTIVE

Twenty-five years of experience with subclavian revascularizations were reviewed to determine the long-term patency rates of different extrathoracic approaches.

SUMMARY BACKGROUND DATA

Although it is generally agreed that proximal subclavian stenosis should be treated by an extrathoracic route whenever possible, the optimum procedure is debated. Alternatives include subclavian carotid bypass, subclavian-to-subclavian or axillo-axillary bypasses, and the authors' preferred technique of subclavian carotid transposition (SCT).

METHODS

Records were researched for the past 25 years in a single specialty surgical clinic for extrathoracic subclavian revascularizations. One hundred ninety such procedures were identified, and hospital charts and office medical records were reviewed for procedure, preoperative symptoms, blood pressure differentials, and postoperative complications. Patency was determined by physical examination, differential blood pressures, Doppler spectral analysis, duplex examinations, and arteriography.

RESULTS

Bypass procedures were used infrequently, and although the results are reported, they are excluded from any analysis. Subclavian carotid transposition was used in 178 procedures. All anastomoses were found to be patient at follow-up, except for one, which failed at 26 months. Mean follow-up was 46 months, with five patients lost to follow-up. Overall mortality rate was 2.2%, with the mortality falling to 1.1% if only subclavian carotid transposition patients are included.

CONCLUSIONS

Subclavian carotid transposition should be the treatment of choice for routine subclavian carotid occlusive disease because of its exceptional long-term patency and low morbidity.

Cryopreserved saphenous vein allografts for below-knee lower extremity revascularization

OBJECTIVE

Cryopreserved saphenous vein allografts have been offered as an alternative conduit for bypass in ischemic limbs. The authors examined the efficacy of this conduit for arterial bypass to the distal popliteal and tibial arteries in patients in whom autogenous vein was not available.

SUMMARY BACKGROUND DATA

Previous experience with arterial and venous allografts has been unsatisfactory because of aneurysmal degeneration and poor patency. Endothelial loss and host rejection have been suggested as mechanisms of graft failure. Cryopreservation by modern techniques with rate controlled freezing, dimethyl sulfoxide (DMSO), and other cryopreservants, has addressed these issues and rekindled interest in vein allografts.

METHODS

Over a period of more than 5 years, 115 cryopreserved vein allografts were implanted in 87 limbs to the distal popliteal (14) or tibial (101) arteries. The indication for surgery was rest pain in 56 procedures (49%), gangrene in 36 (31%), claudication in 21 (18%), and replacement of aneurysmal allografts in 2. Follow-up was 1 to 61 months (mean 25 months).

RESULTS

There was no significant difference in patency related to site of proximal or distal anastomosis, patency of runoff vessels, use of anticoagulation, age, sex, diabetes, hypertension, smoking, indication, source of graft, or use of multiple segments. Revision was required in six grafts for aneurysmal dilatation. Histologic examination of explanted sections of allografts showed no immune response, and immunosuppressive drugs were not used.

CONCLUSIONS

Although limb salvage has been satisfactory, long-term patency rates for cryopreserved vein allografts are poor when compared with autogenous vein. The cost of cryopreserved allografts far exceeds that of prosthetic grafts, for which comparable and superior results have been reported. Use of cryopreserved vein allografts should be reserved for situations in which adequate lengths of autogenous vein do not exist and the risk of infection of prosthetic grafts is high.

Recurrent aortic occlusion

In a review of 134 aortic occlusions in 123 patients, there were 10 patients that suffered recurrent aortic occlusions (RAO). These patients developed RAO after revascularization for primary aortic occlusion and presented with signs and symptoms of acute lower extremity ischemia. The recurrent occlusions occurred in one native aorta and in 10 aortobifemoral grafts. The etiology of the primary aortic occlusion included chronic aortic occlusion in eight patients and acute aortic occlusion and aortic graft occlusion in one patient each. Original primary operations performed included aortoiliac thromboendarterectomy with Dacron patch aortoplasty (1 patient), AF bypass (8 patients), and aortofemoral graft thrombectomy (1 patient). All of the grafts had end-to-end proximal anastomoses, the diameter of which ranged from 12 to 16 mm. Secondary operations performed for RAO included six axillofemoral bypasses, four redo aortobifemoral bypasses, and one graft thrombectomy. All patients were managed with immediate anticoagulation, expeditious arteriography, and revascularization. There were no perioperative deaths, and no limbs were lost. No patient was lost to follow-up (mean 10 years). Extra-anatomic bypass has proved durable. Redo aortobifemoral bypass is useful in selected patients with surgically correctable lesions.

Suprarenal aortic occlusion

PURPOSE

This report was designed to elucidate the clinical manifestations of suprarenal aortic occlusion (SRAO) and determine the efficacy of surgical treatment.

METHODS

A retrospective review of 135 patients with aortic occlusion was undertaken from which the 16 patients (12%) with SRAO were found.

RESULTS

Analysis yielded two subsets of patients based on the time-frame over which SRAO developed. Group I (n = 13) had chronic aortic occlusion with proximal propagation of thrombus to involve the suprarenal aorta. They had uncontrolled hypertension and claudication. Surgical treatment included 16 renal reconstructions (nine patients), two nephrectomies, 10 aortobifemoral bypasses, and three extra-anatomic procedures. The operative mortality rate was 23%. In contrast, group II (n = 3) had acute SRAO, manifest by profound lower extremity ischemia and acute renal failure after cardiac dysrhythmias. Two patients were moribund and died shortly after extraanatomic "salvage" procedures. One patient survived aortobifemoral and bilateral renal artery bypass.

CONCLUSION

Chronic SRAO should be suspected in patients with absent femoral pulses and refractory hypertension. Aortic and renal reconstruction offers long-term improvement in hypertension control and relief of claudication. Acute SRAO is a multisystem disorder that is ineffectively managed with extraanatomic "salvage" procedures.

Cefamandole versus cefazolin in vascular surgical wound infection prophylaxis: cost-effectiveness and risk factors

PURPOSE

Recent studies of perioperative antimicrobial prophylaxis have indicated an improved efficacy of beta-lactamase-stable cephalosporins compared with cefazolin, the most commonly used prophylactic agent. Previous studies in our institution have revealed a superiority of cefamandole to cefazolin in patients undergoing heart surgery, although there was no difference between cefazolin and cefuroxime in patients undergoing peripheral vascular surgery. This study was therefore designed to compare cefamandole with cefazolin in wound infection prophylaxis in clean vascular surgery.

METHODS

The study was conducted from August 1990 through May 1992 and consisted of 893 patients with aortic or infrainguinal arterial procedures randomized to receive either cefamandole or cefazolin.

RESULTS

The difference in infection rates associated with cefamandole versus cefazolin prophylaxis (3.2% vs 1.9%, respectively) was not significant (p = 0.42). A cost savings of approximately $95,000 per year at our institution favors the continued use of cefazolin over cefamandole. Risk factor analysis was carried out for preoperative and postoperative events that might have predisposed to infection. Only preoperative use of aspirin and the postoperative finding of a lymphocele correlated with a higher infection rate.

CONCLUSIONS

Cefazolin continues to be the most cost-effective antibiotic for prophylaxis in clean vascular surgical procedures.

Dysphagia lusoria: aberrant right subclavian artery with a Kommerell's diverticulum

A retroesophageal right subclavian artery, the most common congenital aortic arch abnormality, is an unusual cause of dysphagia in adults. The embryologic abnormality of the aortic arch is involution of the fourth vascular arch, along with the right dorsal aorta, leaving the seventh intersegmental artery attached to the descending aorta. This persistent intersegmental artery assumes a retroesophageal position as it proceeds out of the thorax into the arm. Since compression of the esophagus by this right subclavian artery may produce dysphagia, the term "dysphagia lusoria" ("dysphagia by freak of nature"), has been used to describe the symptom complex. The presence of an aneurysm of the artery or Kommerell's diverticulum at its aortic origin is more likely to produce symptoms from esophageal compression. This case presents a middle aged adult with an associated Kommerell's diverticulum and dysphagia. Surgical correction was used to relieve his symptoms and to correct the diverticulum of the proximal right subclavian artery. The embryologic changes that occur are discussed in detail.

Surgical treatment of common carotid artery occlusion

Eight patients with common carotid artery (CCA) occlusion underwent bypass with saphenous vein to either the carotid bifurcation (five), the internal carotid artery (two), or the external carotid artery (one). Indications included ipsilateral transient ischemic attack (two), recent nondisabling hemispheric stroke (two), and transient nonhemispheric cerebral symptoms (two). Two asymptomatic patients with CCA occlusion and contralateral internal carotid stenosis underwent prophylactic revascularization prior to planned aortic surgery. There were no perioperative strokes, occlusions, or deaths. Late ipsilateral stroke occurred in two patients, and one patient had a single transient ischemic attack after 2 years. The four patients with preoperative transient cerebral ischemia experienced relief of their symptoms. Duplex ultrasound is an accurate screening modality for distal patency. Collateral filling of the internal or external carotid artery can usually be demonstrated after aortic arch or retrograde brachial contrast injection. End-to-end distal anastomosis after endarterectomy eliminates the original occlusive plaque as a potential source of emboli. The subclavian artery is preferred for inflow on the left. The CCA origin is easily accessible for inflow on the right. Bypass of the occluded CCA is safe and may be effective in relieving transient cerebral ischemic symptoms, although long-term ipsilateral neurologic sequelae may still occur.

Neonatal pain: a comprehensive survey of attitudes and practices

We surveyed 352 physicians board certified in neonatal-perinatal medicine on their attitudes and practices in the area of pain and pain management in neonates and infants. In contrast to earlier surveys of this type, almost all respondents indicated that even the youngest and most premature infants are able to perceive pain, and most reported that they always advocated anesthesia during the intraoperative period. The use of analgesic agents in the postoperative period, however, was more variable. Respondents who indicated that neonates perceived less pain than adults reported seeing fewer signs of pain and using less analgesia in the postoperative period. They were also more likely to believe that analgesics are too dangerous to use in neonates and that physiologic factors such as incomplete myelination of the pain pathways and neural/physical immaturity (factors now known not to play a role) contribute to diminished pain sensitivity. Conversely, respondents who indicated that neonates do not perceive less pain than adults, the majority of respondents, reported seeing more signs of pain and using more medication in the postoperative period. These physicians also believed that the physiologic stress associated with pain can be more dangerous than the analgesics. We conclude that attitudes and reported practices have changed in the area of neonatal pain and pain management. Furthermore, our data indicate that these attitudes significantly predict reported postoperative medicating practices.

The evolving surgical management of recurrent carotid stenosis

The traditional approach to recurrent carotid stenosis has been repeat endarterectomy or patch angioplasty. Concern with the durability of repeat carotid endarterectomy has resulted in our use of carotid resection with autogenous graft interposition. This study was designed to determine the outcome and efficacy of carotid resection compared with repeat carotid endarterectomy in the management of recurrent carotid stenosis. From 1974 to 1991, 162 operations (repeat carotid endarterectomy 105, carotid resection 57) were performed for recurrent carotid stenosis. Indication for operation was hemispheric symptoms in 63% of patients, nonlateralizing symptoms in 25%, asymptomatic stenosis in 7%, and previous stroke in 5%. Ninety-one percent of patients had stenosis greater than 90% on arteriography. The perioperative stroke rate for carotid resection was 3.5%, with a subsequent rate of 0.0064 strokes per year. For repeat carotid endarterectomy, the perioperative stroke rate was 1.9% with a subsequent rate of 0.011 strokes per year. Graft patency after carotid resection was 93% (mean follow-up, 35 months). Four patients treated with carotid resection had graft thrombosis, and two of the four remained asymptomatic. After repeat carotid endarterectomy, one patient had carotid thrombosis, and recurrent stenosis greater than 50% developed in 23 patients (mean follow-up, 64 months). Twenty patients treated with repeat carotid endarterectomy underwent an additional operation for further symptomatic recurrent carotid stenosis. We conclude carotid resection is a safe and effective alternative to repeat carotid endarterectomy for patients undergoing operation for recurrent carotid stenosis.

Juxtarenal aortic occlusion

The authors' experience with 113 aortic occlusions in 103 patients during a 26-year period (1965 to 1991) is reviewed. The authors found three distinct patterns of presentation: group I (n = 26) presented with acute aortic occlusion, group II (n = 66) presented with chronic aortic occlusion, and group III (n = 21) presented with complete occlusion of an aortic graft. Perioperative mortality rates were 31%, 9%, and 4.7% for each respective group and achieved statistical significance when comparing group I with group II (p = 0.009) and group I with group III (p = 0.015). Group I presented with profound metabolic insults due to acute ischemia and fared poorly. Group II presented with chronic claudication and did well long-term. Group III presented with acute ischemia but did well because of established collateral circulation. The treatment and expected outcome of aortic occlusion depends on the cause.

Surviving gastrointestinal infarction due to polyarteritis nodosa: a rare event

Poly arteritis nodosa (PAN) is a systemic vasculitis with a male: female ratio of 2:1 and a peak incidence in the fifth decade. Small to medium-sized arteries are involved by focal transmural inflammatory necrosis. Aneurysms with inflammatory destruction of the media also occur. The most frequently involved organs are the kidney, heart, lung, liver, and gastrointestinal tract. There are few reported cases of ischemic necrosis of the intestine and even fewer survivors. A 22-year-old woman was transferred to St. Thomas Hospital (Nashville, TN) after resection of 80 per cent of the small bowel for ischemic necrosis. She had a history of juvenile onset diabetes mellitus, recurrent abdominal pain, and splinter hemorrhages. Emergency aortogram and selective mesenteric arteriogram were performed. The celiac artery was not visualized and small aneurysms were present in the mesenteric and renal arteries. The patient was successfully resuscitated from a cardiac arrest in x ray from a cardiac tamponade. Laparotomy was performed to determine the viability of the bowel. The celiac, hepatic, and splenic arteries were found to be chronically occluded. Pathology of these arteries revealed a nonspecific arteritis. At a third operation, several more inches of small bowel were removed. Characteristic changes of PAN were present on all small bowel specimens. She was treated with high-dose cyclophosphamide and steroids for 6 months and has continued on low-dose cyclophosphamide. She is now 36 months from her original operation and is doing well on oral nutrition. Intestinal hemorrhage from aneurysm rupture or gangrene with perforation are gastrointestinal complications of PAN that the surgeon may be called upon to treat.(ABSTRACT TRUNCATED AT 250 WORDS)

Cefuroxime versus cefazolin as prophylaxis in vascular surgery

Although cefazolin prophylaxis has proven efficacy in vascular surgery, Staphylococcus aureus wound infections are still an important postoperative complication. In cardiac surgery, cefazolin's susceptibility to hydrolysis by staphylococcal beta-lactamase has been proposed to account for some prophylaxis failures. To determine whether the incidence of vascular wound infections can be reduced by administering a more beta-lactamase-stable cephalosporin, we undertook a prospective, randomized trial of cefuroxime versus cefazolin. Cefuroxime was administered as a 1.5 gm dose before operation and 750 mg every 3 hours during operation. Cefazolin was given as 1 gm before operation and 500 mg every 4 hours during operation. Both agents were continued every 6 hours after operation for 24 hours. Deep wound infections developed in seven of 272 (2.6%) cefuroxime and three of 287 (1.0%) cefazolin recipients (p = 0.2). Staphylococcus aureus wound infections occurred in five cefuroxime versus two cefazolin recipients. In vitro evaluation of six of the study isolates plus an additional eight S. aureus strains from vascular wound infections showed greater susceptibility of the strains to cefazolin than cefuroxime (median minimal inhibitory concentrations of 0.5 and 2.0 micrograms/ml, respectively, p less than 0.05). Furthermore, despite its more frequent intraoperative redosing, cefuroxime exhibited lower trough serum concentrations than cefazolin. Among cefuroxime recipients, infection-associated procedures were significantly longer than infection-free procedures (p less than 0.05), suggesting that low tissue antibiotic concentrations may have contributed to the pathogenesis of these infections. In contrast, the length of the procedure was not a risk factor for infection among cefazolin recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluating quality, cost-effective health care. Vascular database predicated on hospital discharge abstracts

This population-based study examines all carotid endarterectomies (CE) performed by all surgeons in a single state over a 10-year period. The methodology is designed to determine morbidity rate, mortality rate, cost, and length of stay, as well as to understand the effect of pre-existing chronic disease, physician, and hospital volume on these outcome variables. The data source consisted of hospital discharge abstract data uniformly collected on all admissions (N = 5.9 million) to acute care hospitals in the state. In the decade 1979 to 1988, 11,199 patients underwent CE. Mortality rate from CE was 2.1%, and the postoperative stroke rate was 3.7% over this period. High physician volume decreased the mortality rate (p less than 0.05) and stroke rate (p less than 0.01) by 50% and significantly (p less than 0.001) reduced hospital cost and length of stay independent of patient complexity. Examination of cost data, adjusted for inflation, showed a decrease in mean cost for CE over the decade. Thus physicians are providing better care for less hospital dollars. Both patient and payor outcome is improved by concentrating CE patients in the hands of high-volume surgeons. Although the data suggests this trend is already evolving, the pace of this evolution can be expected to increase as payors recognize that regionalization of this procedure lowers costs.

Human values and marijuana use

The purpose of this study was to examine the relationship between prioritized rankings of human values among persons who either use or do not use marijuana. Discriminant analyses indicated that personal values are more important to marijuana users, while social values are more important to nonusers. Based upon the present study and previous research, the existence of a value orientation predisposing some individuals toward substance experimentation and use is suggested.

Extended profundoplasty to minimize pelvic and distal tissue loss

Multiple levels of aortoileofemoral occlusive disease may necessitate profundoplasty or extension of the outflow anastomosis to insure pelvic and distal arterial perfusion. During the period 1978 through 1988, 1637 patients underwent elective aortic reconstruction for aneurysmal or occlusive disease. One hundred forty-five had profundoplasty performed to ensure adequate outflow. Associated disease was common with 88 (60%) patients having arteriosclerotic heart disease and chronic obstructive pulmonary disease (COPD) present in 89 (61%) patients. Hypertension and extracranial occlusive disease was found in 68 (46%) and 56 (38%) patients, respectively. The superficial femoral artery was occluded in 108 (74%) patients, while in 17 (12%) the profunda femoris was the only patent artery in the groin. Death occurred in nine patients (6.2%). Three were due to arrhythmias or myocardial infarction and ischemic colitis was the cause of death in two. Renal failure, sepsis, aspiration and cerebral anoxia, and disseminated intravascular coagulopathy accounted for one each. Five graft limbs failed. Amputation was required in one patient, while thrombectomy or distal bypass restored flow in four patients. Seventeen graft limbs in 136 patients occluded during the follow-up period. Distal bypass was successful in four and amputation was required in the fifth patient. Extension of the profundoplasty restored flow in nine limbs, while thrombectomy alone was successful in one. Bilateral amputation was required in one patient with poor run off and insufficient autogenus venous tissue. One hundred fourteen (78.6%) of the 145 patients survived 10 years with patency in 268 of the original 290 limbs at risk (92.4%). Profundoplasty in these patients with multilevel disease seems to extend the long-term patency of aortofemoral grafts and allows return to a normal life-style.

Major hepatic resection: an update

In 1981, we reported a series of 75 major hepatic resections done over a ten-year period; 58 were for hepatic trauma, nine were for benign disease, and eight were for malignant disease. Since that report, the indications for major hepatic resection have changed, with a more conservative approach to hepatic trauma and a more aggressive approach toward hepatic tumors. In this update, we report 88 hepatic resections from Vanderbilt University Hospital and Metropolitan Nashville General Hospital; 32 were for trauma, 25 were for benign disorders, and 31 were for malignant disease. Since 1977, nine adults and four children have had hepatic resection for primary malignant tumors; there were six hepatocellular lesions, three hepatoblastomas, two malignant hemangioendotheliomas, one malignant hepatoma, and one intrahepatic cholangiocarcinoma. At the time of this writing, the four children have survived for 7.3, 6, 6, and 3.8 years (mean 5.7), and all are alive without evidence of recurrence. For the nine adults, survival has averaged 1.7 years, excluding one postoperative death. Three adult patients are alive at this writing, one of whom is a five-year survivor without evidence of disease. Seventeen adults and one child had hepatic resection for metastatic lesions. In the adults, the primary tumor was in the colon in 14 cases and in the small bowel, stomach, and an unknown site in one case each. The one child had a metastatic Wilms' tumor. Survival has averaged two years, with two long-term survivors (nine years). Six patients are alive at this time. Operative mortality for elective resection has decreased from 12% (2/17) in our earlier report to 3% (1/31) in this series, which has encouraged us to assume a more aggressive approach to the resection of malignant primary and metastatic liver tumors.

Recurrent carotid artery stenosis. Resection with autogenous vein replacement

Recurrent carotid artery stenosis (RCAS) occurs in 10% to 15% of patients following carotid endarterectomy (CEA). A recurrent stenosis may occur as early as 6 months and will become symptomatic in 3% to 5% of patients. Early stenosis is myointimal hyperplasia, but with the passage of time may progress to the characteristic atherosclerotic lesion. Improvements in noninvasive testing allows for evaluation and early detection of restenosis. Since 1974 we have performed 3711 CEAs in 2909 patients. One hundred and six second or third CEAs were performed in 98 patients (3.5%). In 20 of these reoperations, the common carotid (CCA) and internal carotid artery (ICA) were resected and replaced by autogenous vein, usually saphenous. One of these patients had 3 previous CEAs while 7 patients had 2 and 12 patients had 1 previous operation. There were no deaths; thrombosis of one vein interposition requiring replacement occurred. Hoarseness and hypoglossal nerve palsy occurred in one patient. Follow-up ranged to 5 years with a mean of 2.8 years. Although a second CEA is possible, there are inherent technical difficulties that may be encountered and vein interposition will solve these as well as offer the potential to prevent a further recurrence.

Analysis of a decade of carotid reconstructive operations

Carotid artery reconstruction surgery for atherosclerotic lesions of the extracranial cerebral circulation has become the most common peripheral vascular operation. A better understanding of the indications for operative intervention, enhanced monitoring during surgery, and more precise management of intraoperative anesthesia have all decreased the risks associated with internal carotid endarterectomy (ICA). In an effort to evaluate the safety and efficacy of extracranial carotid reconstructive surgery, we reviewed 3028 operations performed in 2198 patients during the past decade (1977-1986). Operation was recommended because of hemispheric symptoms in 59% of cases. Fourteen percent were advised to have endarterectomy because of an asymptomatic, significant ICA stenosis. Postoperative hemiparesis occurred in 24 patients (1.1%) and was associated with thrombosis at the operative site in 18 patients. Antiplatelet drugs utilized during the last four years were effective in preventing thrombosis at the operative site. Operative mortality during the decade was 1.2%. Follow-up has ranged from one to. 104 months with 86% of the patients alive and 87% symptom free.

A multicenter randomized, placebo-controlled trial of surfactant therapy for respiratory distress syndrome

We carried out a multicenter randomized, placebo-controlled trial to evaluate the efficacy and safety of surfactant in the treatment of respiratory distress syndrome. The study population was made up of newborn infants weighing 750 to 1750 g who were receiving assisted ventilation with 40 percent or more oxygen. The eligible infants received a single dose of either surfactant (100 mg of phospholipid per kilogram of body weight [4 ml per kilogram]) or an air placebo (4 ml per kilogram), administered into the trachea within eight hours of birth by an investigator not involved in the clinical care of the infant. When compared with the infants who received the placebo (n = 81), the infants who were treated with surfactant (n = 78) had a 0.12 greater average increase in the ratio of arterial to alveolar oxygen tension (P less than 0.0001), a 0.20 greater average decrease in the fractional inspiratory oxygen concentration (P less than 0.0001), and a 0.26-kPa greater average decrease in the mean airway pressure (P less than 0.0001) during the 72 hours after treatment. Pneumothorax was less frequent among the infants treated with surfactant than in the control group (13 percent vs. 37 percent; P = 0.0005). There were no statistically significant differences between the groups in the proportion of infants in each of five ordered clinical-status categories on day 7 (P = 0.08) or day 28 (P = 0.75) after treatment. There were also no significant differences between the groups in the frequency of bronchopulmonary dysplasia, patent ductus arteriosus, necrotizing enterocolitis, or periventricular-intraventricular hemorrhage. In each group, 17 percent of the infants died by day 28. We conclude that treatment with the single-dose surfactant regimen used in this study reduces the severity of respiratory distress during the 72 hours after treatment and decreases the frequency of pneumothorax, but that it does not significantly improve clinical status later in the neonatal period and does not reduce neonatal mortality. Further study of different surfactant regimens and patient-selection criteria will be required to determine whether this initial improvement can be translated into reductions in mortality or serious morbidity.

Long-term assessment of a damp-stored, albumin-coated, knitted vascular graft

In a previous study the authors reported greater endothelialization and thrombus-free surface area in albumin-coated grafts compared with collagen-coated grafts after 1 month's aortic interposition. Another study was undertaken to determine whether these differences persisted after a 6-month implantation period. A 6 cm segment of either an albumin-coated [n = 6] or a collagen-coated [n = 4] graft was implanted into a canine descending thoracic aorta for 6 months. Light micrographs from multiple sections of each explanted graft were scored from 1 to 4, least to most, for tissue ingrowth, perigraft inflammation, and capsular thickness. Using computer planimetry, luminal thrombus free surface area and endothelial coverage were calculated from gross and electron photomicrographs, respectively. The results were averaged and expressed as mean +/- standard error (SEM). After 6 months, no significant differences were noted between the albumin-coated grafts and the collagen-coated grafts, both of which were durable and served equally well as scaffolds for vascular remodeling and tissue incorporation. The authors conclude that the safety, ease of handling, low porosity, low thrombogenicity, and durability of the albuminated grafts warrant their clinical trial.

Renal artery aneurysm: selective treatment for hypertension and prevention of rupture

Thirty-nine patients with renal artery aneurysm (RAA) were seen over a period of 15 years. Among 20 women and 19 men, 31 were found to have solitary aneurysms, and eight had multiple RAA. Thirty-three patients had diastolic hypertension; nine of them proved to be of renovascular origin. Of the 18 patients who underwent RAA resection, 13 had reconstruction for treatment of hypertension, three had a solitary functional kidney, one had recurrent flank pain, and one had resection for prevention of rupture in a woman of childbearing age. Six of the 18 patients had aneurysmorrhaphy with primary repair or patching, seven had a resection with an aortorenal bypass, and five patients had six ex vivo renal reconstructions with multiple anastomoses. Nephrectomy was performed in two patients with RAA rupture at the time of childbirth and in one patient with hypertension and RAA in a poorly functioning kidney. Reconstructive procedures for documented renovascular hypertension in seven patients resulted in improvement in all cases. Blood pressure improved in only six of 10 patients operated on with hypertension and no lateralization of renovascular studies. Eighteen patients were observed for one to 16 years without surgery, and none experienced rupture. Resection of RAA is indicated to treat patients with renovascular hypertension, patients with hypertension and a solitary functional kidney, and selected patients with severe hypertension and to prevent rupture in women who may become pregnant. Other patients with asymptomatic RAA can be safely observed clinically without serial arteriograms and without fear of rupture.(ABSTRACT TRUNCATED AT 250 WORDS)