Complications of Ultrasound-Guided Renal Transplant Biopsies.

Renal transplant biopsies to diagnose transplant pathology are routinely performed using ultrasound guidance. Few large studies have assessed the rate and risk factors of major biopsy complications. This study is a single-center 5-year retrospective cohort analysis of 2514 biopsies. Major complications occurred in 47 of 2514 patients (1.9%) and included hospitalization, transfusion of blood products, operative exploration and interventional radiology procedures. The complication rate among "cause" biopsies was significantly higher than in "protocol" biopsies (2.7% vs. 0.33%, p < 0.001). Complications presented on postbiopsy days 0-14, with the majority diagnosed on the same day as the biopsy and manifested by hematocrit drop, although the presence of such delayed presentation of complications occurring >24 h after the biopsy on days 2-14 is previously unreported. Specific patient characteristics associated with increased risk of a complication were increased age and blood urea nitrogen, decreased platelet count, history of prior renal transplant, deceased donor transplant type and use of anticoagulant medications but not aspirin.

Bilateral segmental agenesis of the vertebrobasilar junction: developmental and angiographic anatomy.

BACKGROUND AND PURPOSE: Bilateral vertebrobasilar junction agenesis is an exceptional anatomic variation. This article explores the angiographic characteristics of this variant and its embryologic mechanisms. MATERIALS AND METHODS: Two observations of bilateral agenesis of the vertebrobasilar junction are reported. A case of atheromatous disease of the vertebrobasilar junction is shown to highlight characteristics distinguishing such a lesion from the reported variant. RESULTS: In the 2 reported cases, the distal segment of both vertebral arteries (VAs) and the proximal portion of the basilar artery (BA) were absent. In addition, distal connections of the BA with the posterior cerebral arteries (PCA) were also lacking. As a consequence, the remaining portion of the BA was isolated from its usual sources of blood supply, which was provided by a persistent carotid-basilar anastomosis. CONCLUSION: The developmental mechanism underlying bilateral agenesis of the vertebrobasilar junction likely involves the anterior radicular artery of C1. This branch of the proatlantal artery normally becomes the adult distal VA and the proximal BA. The lack of cranial connection of the BA with the PCA may be secondary to the proximal vertebrobasilar agenesis and the resulting paucity of antegrade flow within the BA. Alternatively, the absence of both the proximal and distal connections of the BA could be the result of a similar, yet unknown, developmental mechanism. From a clinical standpoint, this vascular anomaly was discovered incidentally in our 2 patients, a finding consistent with the assumed congenital nature of the variant.

Developmental anatomy of the distal vertebral artery in relationship to variants of the posterior and lateral spinal arterial systems.

BACKGROUND AND PURPOSE: A certain number of anatomic variants involving the distal vertebral artery (VA) are explained by variations in size and connection of the lateral spinal artery (LSA). This study examined the possible role of another branch of the VA, the posterior spinal artery (PSA), in the development of similar vascular variations. MATERIALS AND METHODS: Four types of variations in the distal VA, including the C1 and C2 origins of the posterior inferior cerebellar artery (PICA), the duplication of the distal VA, and the aberrant course of the distal VA, are illustrated by 9 angiographic observations. RESULTS: For each type of VA variant listed above, examples resulting from variations in size and connection of the LSA and PSA could be matched. CONCLUSION: Variation in size and connection of the PSA is at the origin of a set of anatomic variations of the distal VA similar, but not identical, to the vascular variants linked to the LSA.

Limitations of informed consent for in utero gene transfer research: implications for investigators and institutional review boards.

Only 10 years after the first human gene transfer protocols were approved for adults and children, researchers have begun to consider gene transfer on the fetus. While preliminary animal research is ongoing, the enthusiasm and pace of research in this area suggest that human protocols for in utero gene transfer research may be seriously considered in the foreseeable future. Federal guidelines for fetal research rely on minimizing risk and informed consent to protect the "rights and welfare" of both the fetus and pregnant woman. However, in utero gene transfer research poses special challenges to informed consent. This research represents an innovative approach for very ill subjects and takes place in the prenatal setting. These features may converge to undermine the expectant parents' comprehension of, and voluntariness for participation in, research. In this case, informed consent may not be able to bear the weight of adequately protecting the fetus from undue research risks. To compensate for this limitation, and using the regulations for pediatric research as a guide, a greater emphasis should be placed on the benefit/harm assessment rather than informed consent. Selecting diseases/patients where good alternative treatments exist may maximize informed consent, yet this may be a trade-off that exposes the fetus to greater relative risks. On the other hand, selecting diseases/patients without good alternative treatments to prolong life may convey an overestimation of the potential benefits of these interventions, and although care should be taken to strive to improve understanding of these limitations, misunderstanding may persist. However, selecting diseases/patients with no good alternatives might make serious risks more tolerable, and this should take precedence over informed consent. The limitations of informed consent brought into focus by the special features of in utero gene transfer research may be relevant to a broader range of innovative investigations.