Biomedical subjects

B J Lenz

Publications and source records attributed to B J Lenz.

3 recordsLinked to original sources

PubMed1998

A three-year follow-up on standard versus thin wall ePTFE grafts for hemodialysis.

PURPOSE: Expanded polytetraflouroethylene (ePTFE) grafts are the most popular prosthetic grafts for hemodialysis patients in whom autogenous fistulas cannot be constructed. Long-term studies to study the durability and complication rate of the different wall configurations of ePTFE grafts have not been carried out. The primary, secondary, and cumulative patency and other complications between standard thickness (STD) and thin wall (THN) 6 mm stretch ePTFE grafts (WL Gore & Assoc, Flagstaff, AZ) was prospectively evaluated. METHODS: From September 1993 to August 1995, 108 patients receiving new grafts were randomized into 2 groups: those receiving STD grafts (n = 56) or those receiving THN (n = 52) grafts. Data prospectively collected included day of first access, primary patency, interventions required, and long-term results. Infections, pseudoaneurysms, and mortality were also documented. Student's unpaired t-test was used to compare the 2 groups, and log-rank life tables were constructed and compared. RESULTS: Mean follow-up examination time was 38.1 +/- 0.8 months for STD grafts and 35.1 +/- 1.0 months for THN grafts (P<.03). Longer patency was noted in the STD group of grafts (18.2 months for STD vs. 12.1 months for THN). Biographical data and complications, including pseudoaneurysm (6% vs. 5%), infection (2% vs. 3%), and mortality (22% vs. 19%), between STD and THN groups were not different statistically. Mean primary (18.2 months vs. 12.1 months), secondary (20.9 months vs. 13.7 months), and cumulative patency times (22.2 months vs. 15.2 months) for the STD group were significantly more than those for the THN group (P<.000 by log rank of life tables). Other complications were not different between groups. CONCLUSION: Standard thickness ePTFE is the graft of choice when placing ePTFE arteriovenous grafts for hemodialysis.

Adolescent↗

PubMed1997

Current issues in living donor nephrectomy.

Of 96 consecutive renal transplants in 2 years, 50 (52%) were living donor grafts. Donor demographics, treatment plans, length of stay (LOS), charges, and complications were reviewed. Donors included 27 women and 23 men aged 22 to 61 (mean 42.2) years; 33 were living related and 17 living unrelated donors. Racial distribution included 1 Hispanic, 2 Asian, 8 black, and 39 white donors. Pretransplant evaluation defined renal anatomy and function (minimal creatinine clearance 75 cc/min). Hospital admission occurred the morning of donation. Nephrectomy under general anesthesia entailed an anterior flank, extra-retroperitoneal approach (no rib resection); and postoperative epidural pain control was standard. Progressive early ambulation and pulmonary self-care optimized recovery. The 50 donors were hospitalized for 2 (n = 7), 3 (n = 18), 4 (n = 15), 5 (n = 6), and 6-8 (n = 4) days (mean LOS: 3.74 +/- 0.17, range 2-8 days). The mean charge for donor hospitalization was $15,415 +/- $397 (range $10,808-$29,579). One major intraoperative hemorrhage required transfusion; 1 patient was readmitted for wound drainage and pneumonia treated medically. While 40 of 50 patients (80%) were hospitalized for 4 days or less, there was no readmission because of short hospital stay. One early graft loss (3 days) occurred from technical problems; all others gained excellent life sustaining function. Three additional kidneys failed from rejection, noncompliance, and systemic coagulopathy. One recipient died at 8 months (CVA) with normal renal function. Current strategies for successful living kidney donation are thorough patient and family education, ambulatory preoperative testing, morning of surgery admission, and discharge planning beginning before hospitalization. Excellent outcomes may be accompanied by a brief LOS, epidural pain management, and liberal use of willing and healthy related and unrelated living donors.

Adult↗

PubMed1996

Changing patterns of arterial injuries associated with fractures and dislocations.

BACKGROUND: Significant changes occurred over a 4.5-year period in the causes, diagnosis, and treatment of arterial injuries associated with skeletal fractures of the extremities. STUDY DESIGN: The trauma registry data of 1,091 consecutive patients with fractures, dislocations, or both, were reviewed for the diagnosis of associated arterial injury documented by arteriography or an exploratory operation. The decision to perform a vascular repair was based solely on the presence of definitive signs of arterial injury found during physical examination. RESULTS: Arterial injuries occurred in 41 patients (3.8 percent). Of these, 29 (71 percent) had penetrating injuries, and 12 (29 percent) had blunt trauma. Twenty-six patients (63 percent) had definitive signs of arterial injury and all required arterial repairs. Only three patients (7.3 percent), all with blunt injuries, required amputations because of massive soft tissue trauma. Fifteen patients had intimal flaps, irregularities, or localized narrowings shown on the arteriogram. No patient's condition had deteriorated by the time of a repeat arteriogram (n = 6) or physical examination (n = 9), and no injury required delayed repair (mean follow-up of 6.5 months). No patient without definitive signs of vascular injury at the time of initial examination required surgical repair. CONCLUSIONS: Arterial injuries associated with fractures increasingly result from penetrating trauma and carry a much lower risk of amputation than injuries from blunt trauma. Physical examination can accurately detect 100 percent of the arterial injuries requiring repair. Minimal arterial abnormalities seen on arteriograms may be safely followed up by observation.

Adult↗