The bell-clapper deformity of the testis: The definitive pathological anatomy.

INTRODUCTION: The bell-clapper deformity (BCD) predisposes to intravaginal torsion (IVT) and is classically bilateral. The precise pathological definition of what constitutes a BCD is not clear. The current study aims to clarify the specific anatomic details of this anomaly. METHODS: A systematic review was performed utilizing the PRISMA principles. Studies are presented chronologically based on their level of evidence. They are further divided into study types: autopsy and operative studies of acute torsion, intermittent torsion and studies of the contralateral testis in vanishing testis. RESULTS: The bell-clapper deformity is best defined by complete investment of the testis, epididymis and a length of the spermatic cord by the tunica vaginalis. Based on autopsy studies the rate of BCD in scrotal testis varied from 4.9% to 16%; with bilaterality in 66%-100%. In cases of acute IVT bilaterality was noted in 54%-100%. The most disparate results were in cases of testicular regression syndrome where contralateral BCD was noted in 0%-87% of cases. CONCLUSION: We suggest future studies employ the strict anatomical definition above. As there is evidence of age-dependent investment of the testes, it will be important to develop age-standardized measurements of intravaginal length of spermatic cord. This critical morphometric measurement will allow a better understanding of the risk of IVT. LEVEL OF EVIDENCE: Systematic review of diagnostic studies: lowest level of evidence of included manuscripts Level IV (case-control studies with a poor reference standard).

Defining the surface anatomy of the central venous system in children.

Pediatric emergency physicians, pediatric critical care specialists, and pediatric surgeons perform central venous catheterization in many clinical settings. Complications of the procedure are not uncommon and can be fatal. Despite the frequency of application, the evidence-base describing the surface landmarks involved is missing. The aim of the current study was to critically investigate the surface markings of the central venous system in children. The superior vena cava/right atrial (SVC/RA) junction, superior vena cava (SVC) formation, and brachiocephalic vein (BCV) formation were examined independently by two investigators. Three hundred computed tomography (CT) scans collected across multiple centers were categorized by age group into: 0-3 years, 4-7 years, and 8-11 years. Scans with pathology that distorted or obscured the regional anatomy were excluded. The BCV formation was commonly found behind the ipsilateral medial clavicular head throughout childhood. This contrasts with the variable levels of SVC formation, SVC length, and SVC/RA junction. In the youngest group, SVC formation was most commonly at the second costal cartilage (CC), but moved to the first CC/first intercostal space (ICS) as the child grew. The SVC/RA junction was at the fourth CC in the youngest group and moved to the third CC/third ICS as the child grew. This study demonstrates the variable anatomy of SVC formation and the SVC/RA junction with respect to rib level. This variability underscores the unreliability of surface anatomical landmarks of the SVC/RA junction as a guide to catheter tip position.