The anatomical relationship between the intrarenal arteries and the renal collecting system was studied in 82, 3-dimensional endocasts. Some anatomical details that have importance for urologists were observed. The arterial supply related to the upper caliceal group arises from 2 arteries that encircle these calices (in 86.6% 1 trunk originated from the anterior division and 1 from the posterior division of the renal artery). The artery to the mid kidney courses horizontally in the mid renal pelvis in 64.6% of the cases while the arterial supply to the inferior pole (front and back) arises from the inferior segmental artery of the anterior division in 62.2%. The posterior segmental artery is related to the upper infundibulum or to the junction of the pelvis with the upper calix in 57.3% of the cases and to the middle posterior aspect of the renal pelvis in 42.7%.

In addition to the gravity-dependent position, we believe that other particular anatomical features may be important in the retention of stone debris in the lower calices after extracorporeal shock wave lithotripsy (ESWL). We analyzed the inferior pole collecting system anatomy in 146, 3-dimensional polyester resin corrosion endocasts of the pelviocaliceal system. The inferior pole was drained by multiple calices disposed in 2 rows in 56.8% of the cases and by 1 midline caliceal infundibulum in 43.2%. In 60.3% of the cases there was a lower infundibulum equal to or greater than 4 mm. in diameter and 39.7% had a lower infundibulum smaller than 4 mm. in diameter. In 74.0% of the cases an angle of greater than 90 degrees was formed between the lower infundibulum and the renal pelvis, and in 26.0% the angle was 90 degrees or smaller. We believe that the physician should consider these anatomical features when suggesting ESWL to treat calculi in the lower calices.

In addition to gravity-dependent position, we suppose that other particular anatomic features may be important in the retention of stone debris in lower calices after extracorporeal shockwave lithotripsy (SWL). We analyzed the inferior-pole collecting system anatomy in 146 three-dimensional polyester resin corrosion endocasts of the pelviocaliceal system. In 74% of the cases, there was an angle of greater than 90 degrees formed between the lower infundibulum and the renal pelvis, and in 26%, the angle was 90 degrees or less. In 60%, there was a lower infundibulum 4 mm or larger in diameter. The inferior pole was drained by multiple calices disposed in two rows in 57% of the cases and by one midline caliceal infundibulum in 43%. We believe that the physician must appreciate these anatomic features when considering SWL to treat calculi located in lower calices.

In an attempt to determine the best route to puncture and access the kidney collecting system we studied 62, 3-dimensional polyester resin endocasts of the pelvicaliceal system together with the intrarenal vessels. A retrograde pyelogram was obtained, and the arterial and venous trees were injected with red and blue resins, respectively. When the resin was still in the gel state, the kidneys were positioned at 30 to 45 degrees and the collecting system was punctured under radioscopy. Since the resin is not opaque to x-ray the operator was not able to visualize the vessels while puncturing. After puncture, the needle was maintained in place, the contrast medium was removed and the pelvicaliceal system was filled with yellow resin. After the resin had set, the renal organic matter was corroded in acid and the endocast was obtained (with the needle in the original position). This type of preparation allowed us to examine the needle tract and the vessels damaged during the puncture. In the same kidney we punctured the superior pole, mid kidney and inferior pole. In some cases we also punctured the renal pelvis. We performed 104 punctures through an infundibulum, 39 through a fornix of a calix and 12 through the renal pelvis. Due to a high percentage of vascular lesions, intrarenal access through an infundibulum should be avoided. Also, renal pelvis puncture should be avoided. Regardless of the kidney region, puncture through a fornix of a calix was safe.

The anatomical relationships between the renal venous arrangement and the pelviocaliceal system were studied in 52, 3-dimensional polyester resin corrosion endocasts. In 53.8% of the cases, there were 3 large venous trunks and in 28.8% there were 2 venous trunks joining to form the main renal vein. Intrarenal veins demonstrated free anastomoses that were disposed in 3 systems of longitudinal arcades (stellate, arcuate and interlobar veins). There were large venous collars around caliceal necks and also horizontal arches crossing over calices to link anterior and posterior veins. In 84.6% of the cases the upper caliceal group was encircled anteriorly and posteriorly by venous plexuses, which coursed parallel to the infundibulum. In 50.0% of the cases the lower caliceal group also was enriched by 2 venous plexuses. A close relationship existed between a large inferior tributary of the renal vein and the anterior aspect of the ureteropelvic junction in 40.4% of the cases. In 69.2% of the cases there was a posterior (retropelvic) vein: in 48.1% this vein had a close relationship to the junction of the pelvis with the upper calix and in 21.1% it crossed the middle posterior surface of the renal pelvis.