R Chang

Comparison of recurrent varicocele anatomy following surgery and percutaneous balloon occlusion

Venography of 44 recurrent varicoceles in 37 patients demonstrated different anatomical patterns of recurrence in surgical patients (26) compared to those treated by percutaneous balloon occlusion (18). The 3 types of patterns identified included parallel, renal vein and transcrotal collateral pathways. Virtually all surgical recurrences were owing to mid retroperitoneal (27 per cent) or low (inguinal) parallel collaterals (58 per cent). The majority of post-balloon occlusion recurrences were due to either high retroperitoneal parallel (44 per cent) or renal vein collaterals (28 per cent). Surgical recurrences were treated easily with percutaneous balloon occlusion. However, 39 per cent of the patients with recurrences following balloon embolization were not anatomical candidates for repeat percutaneous occlusion. We conclude that venous collaterals are identified easily by renal venography, and knowledge of these collaterals is helpful in planning further surgical or radiological treatment.

Monitoring radiation exposure to medical personnel during percutaneous nephrolithotomy

To ascertain radiation exposure to medical personnel during percutaneous nephrolithotomy, lithium fluoride thermoluminescent dosimeters (TLDs) were utilized for the radiographic monitoring of 7 consecutive patients. Average fluoroscopy time per procedure was 27.8 minutes of which 15.1 minutes were for nephrostomy tube insertion and 12.7 minutes were for calculi extraction. The 2 radiologists received 4.5 and 5.1 mrad per procedure, while the 2 urologists received 2.5 and 3.7 mrad. All other ancillary personnel received less than 2.1 mrad per procedure except the anesthesiologists whose mean exposure was 4.7 mrad. By taking appropriate precautions and using the proper equipment, percutaneous nephrolithotomy can be performed with a low level of radiation exposure for all involved physicians and personnel.

Cystine calculi: Clinical management and in vitro observations

Although cystine stones account for 1 to 3 per cent of renal calculi, many of these patients are difficult to manage because of recurrent urolithiasis. Seven cases of homozygous cystinuria are summarized. The evolution to the present treatment of percutaneous extraction and chemolysis appears to be the preferred form of treatment although extracorporeal shock wave lithotripsy (ESWL) may also be utilized. In addition, in vitro experiments were conducted to study the effectiveness of different chelating agents and buffers at different urinary pHs. The effect of cystinuric and noncystinuric urines was also evaluated.

Upper-extremity venography using digital subtraction angiography

Venography to evaluate the patency of upper-extremity veins was performed with digital subtraction angiography (DSA) and conventional angiography. Venous thrombosis was easily diagnosed, and the innominate veins and superior vena cava were more easily visualized using DSA. Iodine concentration for DSA was one-third that of conventional venography, and the examination time was reduced by 50% using DSA. Patient comfort and acceptance were greater with DSA. DSA is a superior technique for upper-extremity vein evaluation in cooperative patients.

Intraarterial digital subtraction angiography: A comparative view

Intraarterial digital subtraction angiography (IA DSA) was performed in 122 patients undergoing a variety of diagnostic and interventional angiographic procedures. Owing to the increased contrast resolution of DSA, diluted contrast material in concentrations of from 12–19% could be employed, thereby significantly reducing contrast material doses compared to doses used with conventional film-screen angiography or intravenous DSA. Patient discomfort was convincingly reduced due to the injection of dilute contrast material. Subtracted digital images could be viewed immediately on a cathode ray tube (CRT) resulting in faster procedures with less catheter time. Savings in film costs relative to conventional angiography were also achieved.

Percutaneous displacement of calyceal calculi. Adjunct to percutaneous nephrolithotripsy

Two cases are presented of successful percutaneous removal of adherent calyceal calculi which were initially inaccessible for removal with the rigid nephroscope. In each case, the calculus was dislodged from the calyceal wall by the direct force of a needle introduced percutaneously against the stone. In the first patient, a wedged calyceal calculus was dislodged percutaneously and manipulated into the renal pelvis the day before extraction using the rigid nephroscope. In the second patient, the adherent calculus was dislodged percutaneously at the same time of endoscopic removal. In both patients, prior carbon dioxide pyelography was helpful in determining the optimum direction for advancing the needle against the calculus. Percutaneous stone dislodgement technique is a useful adjunct to percutaneous nephroscopic removal of the difficult calyceal calculus.