Retrocaval ureter presenting as an acute abdomen (a case report).
Several vascular anomalies can cause back pressure on the ureter. Commonly, accessory or aberrant renal vessels can do so. However, the circumcaval or retrocaval ureter is an uncommon finding. Of these terms, circumcaval ureter is preferred as the ureter may lie dorsal to the vena cava for some portion of its course without encircling the cava, and this forms the retrocaval ureter developmentally defficient, and simulating a retrocaval ureter. This disorder affects the right ureter which typically deviates medially, dorsal to the inferior vena cava, winding about it and crossing in front of it from a medial direction to a lateral one to resume its normal distal course towards the bladder. The distal ureter and upper collecting system are dilated and. a J shaped, "fish hook" ureter is seen on excretory pyelography [Fig. 1]. It is not necessary that there be complete obstruction.
A new classification has classified circumcaval ureters into Type I which has the earlier J shaped ureter and Type H which may not have the J shaped or the "fish hook" appearance. In Type II the obstruction appears to be at the edge of the ileopsoas muscle and in Type H the obstruction is at the lateral wall of the vana cava, as the ureter is compressed against the perivertebral tissue.
Mr. J. D., a 24 year old male, came to Dr. Pinto's private clinic on 29-6-1982 with acute pain in the right iliac fossa which was radiating from the loin to the groin. Antispasmodics would not relieve the pain. An emergency excretory pyelography was done. The X-ray [Fig. 1] showed a J shaped "fish hook" hydroureter and hydrocalycosis on the right side and normal excretion of the dye on the left side. An ureteric calculus was suspected at the point of obstruction of the right ureter and reported as such by the radiologist. Haematological and urine examinations were normal. The patient's pain worsened and he was later explored through a right subcostal incision on 30-6-1982.
No calculus was found and it was difficult to locate the ureter where the obstruction had been reported on the excretory pyelography. The hydronephrotic segment was traced and- it was found that the ureter had been compressed by the cava at a point above the bifurcation of the cava (L3) as in the Type I classification. The ureter was transected after it was carefully dissected from the cava above and an end-to-end anastamosis was carried out with 5.0 chromic catgut over a splint. The patient had an uneventful recovery. Post-operatively, he was investigated-(1) radiologically, (to find if the collecting system had reduced in size) and (2) by ultrasound. His excretory urogram done on 13-8-82 (about six weeks later) [Fig. 2] showed a dilatation of the calyceal system, but the anastamotic site and the lower ureter could be well visualised. His repeat excretory urogram done on 19-7-1983 (fourteen months after surgery) [Fig. 3], showed a further reduction of the hydrocalycosis and the hydroureter. Ultrasonic dimensions of his kidney and ureter showed a progressive decrease in the size of the collecting system.
Ultrasound on 3-9-83:
Left kidney: 10.11 x 4.9 x 5.4 cm.
Right kidney: 10.77 x 5.7 x 4.8 cm.
Collecting system on the left side: Normal.
Collecting system on the right side: 5 x 2 x 2 cm.
Ultrasound on 29-11-83:
Left kidney: 10 x 5 x 5.4 cm.
Right kidney: 10.2 x 5.2 x 4.6 cm.
Collecting system on both sides normal.
This is an unusual case of a retrocaval ureter which presented as an acute abdomen. This anomaly is more common in children than in adults.,
Various methods have been advocated to correct the defect, one of these being sectioning of the inferior vena cava.,,
In this case, an end-to-end anastomosis of the right ureter with a "fish mouth" on the distal end was carried out over a splint using 5.0 chromic catgut. The patient did well and had an uneventful postoperative recovery. He is now free of pain and back to his work. Ultrasound can be quite helpful in demonstrating post-operative reduction in the size of kidney and ureter after release of obstruction and back pressure, and was therefore used in this case to judge the post-operative recovery of the collecting system of the right kidney to normal dimensions. The use of this modality (ultrasound) in repeated follow-up measurements of the size of the affected kidney and the ureter is strongly advocated as it is quite simple to carry out, gives fairly accurate measurements and, being a non-radiation investigative method, can be used as frequently as desired, with full safety to the patient, without any side effects.