A cadaveric dissection study of the anatomical variations of the ureter and implications for surgical intervention

Abstract

A cadaveric dissection study of the anatomical variations of the ureter and implications for surgical intervention Joan M. Costelloe

The importance of studying ureteric anatomy such that it can be applied to surgical and radiological practice is evident. There are many circumstances in which lack of knowledge or anticipation of variations/anomalies in ureteric anatomy can lead to errors in diagnosis, higher rates of iatrogenic ureteric injury and failure of procedures. The qualitative aims of this study were: (i) to review the normal anatomy of the ureter and to compare the variations found during dissection with those described in the literature, (ii) to obtain high quality images of the ureter and its vascular supply and (iii) to record images displaying common anatomical locations associated with iatrogenic injury. The quantitative aims were: (i) to conduct systematic dissections of the ureter to enable a range of measurements (i.e. general length data, data pertaining to anatomical landmarks and crossing points and gender specific data), (ii) to conduct a statistical analysis of the measurement data and (iii) to highlight the implications of ureteric anatomic measurement for clinical operative and radiological practice, especially in the context of ureteric injury.

Twelve embalmed adult cadaveric donors (five male, seven female) were dissected in the Anatomy Dissection Theatre, Biomedical Sciences Institute, TCD. The dissection was carried out via a transperitoneal approach from the level of the renal hilum to the vesico-ureteric junction. An extensive set of colour images of the ureteric course was recorded. Sets of ureteric measurements (including the length/distance of eight sub-aspects of the ureter) were recorded and subjected to detailed statistical analysis. The presence of anatomical variations and anomalies were identified.

A set of annotated images of the ureteric course, along with schematics and images of the vascular supply to the ureter, were produced. Two anomalies of ureteric anatomy were identified, one case each of an extrarenal pelvis and a partial ureteric duplication. Results: The overall mean total ureteric length was 24.2 ? +/- 2.1 cm. Statistical analysis showed that gender had an effect only in the case of the abdominal and pelvic ureteric lengths and side had an effect only in the case of the distance from the lateral border of the abdominal aorta to the mid-point of the abdominal ureter. The abdominal ureter was longer that the pelvic ureter in the majority of cases in the male donors, while the opposite was the case in females. There was no statistically significant difference between the total ureteric length in males and females or between the total ureteric length on the left and right sides. The results of this study indicated no statistical difference between the distance from the right and left ureters to the midsacral promontory.

When the total length of the ureter was compared with the sub-aspects, three aspects displayed strong association (R2) and acceptable levels of estimation error on linear regression analysis (PUJ to crossing point of the vas deferens, pelvic ureteric length in females and PUJ to crossing point of the gonadal vessels in females). When the right and left ureteric lengths (and lengths of sub-aspects) were compared, two aspects displayed a very strong association (total ureteric length and pelvic ureteric length in males), and two aspects displayed strong association (mid-point of sacral promontory to medial border of ureter in males and PUJ to crossing point of the vas deferens) along with acceptable levels of estimation error on linear regression analysis. This study also provided data on three sub-aspects of the ureter which are not described elsewhere in the literature: the distance from the PUJ to the crossing point of the gonadal vessels, the distance from the PUJ to the crossing point of the vas deferens and the distance from the PUJ to the crossing point of the uterine artery.