Percutaneous removal of kidney stones. Preliminary report.

We have performed percutaneous extractions of renal pelvic stones in 15 patients with the use of the Wolf percutaneous universal nephroscope. At one session, with the patient under general anesthesia, a percutaneous tract is dilated to 24 F, and the stone is immediately removed. Fifteen stones have been removed successfully by ultrasonic lithotripsy, basket retrieval, use of a forceps, or a combination of these techniques. Average operating time has been 1 hour and the mean hospitalization time 4 days. The advantages of this technique are that a skin incision of only 1 to 2 cm is required to remove the stone, hospital days are fewer than with open procedures, and postoperative morbidity is minimal. In selected situations, this method represents a significant advance over standard open surgical procedures for removal of renal pelvic stones.

Early experience with percutaneous cholecystolithotomy.

Percutaneous cholecystolithotomy should be added to the list of alternatives to elective open cholecystectomy for the management of patients with gallstones. Our initial experience with percutaneous cholecystolithotomy in 13 patients (7 men and 6 women who ranged in age from 47 to 83 years) demonstrated that the procedure could be accomplished successfully with acceptable morbidity and no mortality. After a mean duration of follow-up of 10.7 months, only one patient had recurrent cholelithiasis. Because of rapid changes in the therapeutic approach to patients with cholelithiasis, percutaneous cholecystolithotomy may seldom be used.

Low-osmolality contrast media: a current perspective.

Intravascular radiographic contrast media play a major role in diagnostic imaging. Recently, low-osmolality contrast media (LOCM) have become available in the United States. Because of their lower osmolality, these new agents cause fewer undesirable physiologic effects and fewer adverse reactions than do conventional agents after intravascular administration. Unfortunately, the cost of LOCM is substantially higher than the cost of conventional contrast media. Appropriate use of these newer, more expensive contrast agents must be based on a thorough knowledge and understanding of their chemistry, physiologic features, and relative safety. Some questions remain about these new agents. Further studies are needed to determine the nephrotoxicity of LOCM relative to that of conventional agents. In addition, LOCM have less anticoagulant capacity than do the conventional media; therefore, clotting may occur when the LOCM and blood mix in syringes and small catheters. This potential decrease in anticoagulation and its clinical implications should be further investigated. Finally, the mortality rate associated with use of LOCM needs to be determined in future studies in large numbers of patients.

Radiology in the intensive-care unit.

Portable chest radiography is an essential component of clinical patient management in the intensive-care unit. With routine use of this procedure, unexpected cardiopulmonary abnormalities are frequently detected, and malposition or complications of intravascular devices and endotracheal, thoracostomy, or nasogastric tubes are also commonly found. The pulmonary parenchyma may be assessed for changes of acute lung injury, cardiogenic edema, areas of pneumonitis, atelectasis, or other abnormal collections of fluid or air. In mechanically ventilated patients, barotrauma occurs frequently and may be manifested by subtle intrathoracic collections of air. Technical factors may limit the resolution of the anteroposterior chest radiograph obtained at the bedside, but crucial clinical information is often gained. Portable chest radiographic findings, the role of computed tomography and ultrasonography, and interventional radiologic procedures pertinent to patients in the intensive-care unit are reviewed.

Renal cell carcinoma metastatic to the pancreas: clinical and radiological features.

OBJECTIVE: To review the clinical features, computed tomographic (CT) appearance, and treatment outcomes in a case series of patients with renal cell carcinoma (RCC) metastatic to the pancreas. PATIENTS AND METHODS: We retrospectively reviewed the records of 23 patients (15 men and 8 women) with RCC metastatic to the pancreas, detected by CT examination between 1986 and 1996. All patients had undergone a previous nephrectomy for RCC. RESULTS: Isolated mild elevation in liver function test results (in 5 patients) or in serum amylase level (in 8 patients) was observed. New-onset diabetes was detected in 3 patients. The CT characteristics of the pancreatic metastases generally resembled those of primary RCC with well-defined margins and greater enhancement than normal pancreas with a central area of low attenuation. The mean interval between resection of the primary RCC and detection of the pancreatic metastases was 116 months (range, 1-295 months). In 18 patients (78%), the pancreatic metastases were diagnosed more than 5 years after nephrectomy. The pancreas was the initial metastatic site in 12 patients (52%). Survival was shortened with higher tumor grade (mean survival time of 41 months and 10 months in patients with grade 2 and 3, respectively). Surgical resection was carried out in 11 patients (7 distal and 3 total pancreatectomies and 1 distal pancreatectomy followed 4 years later by total pancreatectomy), with 8 patients alive at a mean follow-up of 4 years, 6 of whom remained free of recurrence. Overall, 12 patients (52%) were alive at a mean of 42 months after diagnosis of metastatic disease. CONCLUSIONS: The appearance of metastatic RCC lesions in the pancreas closely resembles the appearance of primary RCC on CT images. Pancreatic metastases from RCC are frequently detected many years after nephrectomy. Patient survival correlates with tumor grade. Histologic analysis of pancreatic masses in patients with a history of resected primary RCC is important since the prognosis for RCC metastatic to the pancreas is much better than that for primary pancreatic adenocarcinoma.

Percutaneous ultrasonic lithotripsy.

Ultrasonic lithotripsy employed with a percutaneous nephroscope is a safe, controlled method of removal of renal and ureteral stones using the techniques described herein. A success rate of 95 to 98 per cent should be achievable.

Percutaneous removal of renal calculi.

Percutaneous removal of symptomatic renal and ureteral calculi evolved in the early 1980s, replacing standard surgical stone removal operations because of reduced patient morbidity and shortened hospitalizations. A wide variety of instruments designed to work through the percutaneous track are available to remove or fragment nearly all renal calculi. Success rates of this modality are excellent, and major complications are few. Despite the wide applications of extracorporeal shock-wave lithotripsy, percutaneous stone removal methods will continue to be needed in some patients.

Extracorporeal shock-wave lithotripsy.

Extracorporeal shock-wave lithotripsy is a new technique for treatment of symptomatic renal and upper ureteral calculi. After biplanar fluoroscopic localization of the targeted calculus, serial shock waves cause calculus disintegration, with subsequent spontaneous transurethral passage of the fragments. Excellent clinical results and patient enthusiasm have resulted. Physicians using extracorporeal shock-wave lithotripsy must also be adept at percutaneous, ureteroscopic, and standard surgical stone removal methods to deal with complex clinical stone presentations.

Percutaneous ultrasonic lithotripsy.

Percutaneous ultrasonic lithotripsy, endoscopically guided calculus fragmentation and removal through a percutaneous track, is the most widely used technique in the United States for removal of symptomatic upper urinary tract calculi. This article reviews the establishment of percutaneous renal access, track dilatation, and stone removal methods that constitute this technique.

Prediction of stone composition from plain radiographs: a prospective study.

BACKGROUND AND OBJECTIVES: Stone composition, as reflected in radiographic appearance, is important to help choose between SWL and percutaneous/endoscopic procedures. Predicting a stone's composition accurately from a plain radiograph would be a useful tool in clinical decision-making. However, the ability of physicians to predict composition has not been adequately assessed. A prospective study was designed to quantify the accuracy of a panel of physicians who routinely deal with stones in classifying stone composition solely from radiographs. MATERIALS AND METHODS: A panel of six members was created to review 100 plain-film radiographs from patients with renal stones of known composition. The panel consisted of two urologists, two radiologists, and two nephrologists, all of whom have expertise in stone disease. If the composition guessed was at least 40% of the total stone composition, the response was deemed correct. RESULTS: Overall, there was an average 39% correct response score among the six panelists. When the stones were divided by size, 35% were <1 cm, and 65% were larger. The accuracy of chemical composition determination did not improve with greater stone size, nor was there a difference in accuracy for pure and mixed stones. The most frequently misclassified stone was calcium phosphate, with only 14% being correctly diagnosed. CONCLUSIONS: With a random sampling of plain radiographs, a panel of physicians specializing in stone disease correctly diagnosed the composition of renal calculi less than half of the time without being given clinical information.

Endoscopic surgery of the upper urinary tract.

Endoscopic surgery of the upper urinary tract had made rapid advances in the past three years. At our institution endoscopic removal of upper urinary tract stones had almost replaced open surgical procedure which is now done in only about 2% of the surgical stones seen. Over 1,000 cases of percutaneous stone removal had been done and for renal and uretero-pelvic junction stones our success rate is 96% while ureteral stones are less amenable to removal and the success rate is about 86%. Complications include procedure bleeding, entravasation of irrigating fluids, perforation of the collecting system and sepsis. All these are rare and can be managed conservatively. A more serious complication is that of AV malformation in six cases out of 1,000 patients due to damage to renal vessels. Fortunately this can be treated with arteriography and embolisation. Retained fragment rate is about 6%, these are, however, non-surgical fragments. Percutaneous techniques may also be used for diagnostic inspection of the collecting system and for treatment of certain cases of uretero-pelvic junction obstruction. Instruments are now also available for transurethral uretero-renoscopy, it is generally possible to manipulate and remove many ureteral stones under direct vision.

Diagnosis and treatment of nephrolithiasis: current perspectives.

Urinary stones are a frequent cause of morbidity in persons in affluent industrialized societies. The surgical management of symptomatic stones in the upper urinary tract has changed dramatically in the past generation, largely because of the introduction of progressively less invasive treatment techniques. The concurrent revolution in radiologic imaging and interventional techniques has mirrored the surgical experience. This article reviews the current diagnosis and therapy of nephrolithiasis. An evaluation of the complex metabolic abnormalities present in the population of patients with urolithiasis is beyond the scope of this article, but several good reviews of this subject have been published recently [1-4]. Because primary urolithiasis involving the bladder or urethra is less common and is a separate medical entity, this article is focused on renal and ureteral calculi.

Helical and electron beam CT scanning in the evaluation of renal vein involvement in patients with renal cell carcinoma.

PURPOSE: The purpose of this study was to assess helical and electron beam CT scanning in the evaluation of renal vein involvement in patients with renal cell carcinoma (RCC). METHOD: Seventy-three patients with 76 pathologically proven RCC who underwent surgical resection or autopsy were evaluated for the accuracy of helical and electron beam CT scanning in the detection of renal vein tumor thrombus in patients with RCC. Patients were entered into the study only if they were scanned on either electron beam or helical CT scanners with intravenous contrast medium enhancement. The tumors involved the right kidney in 38 cases and the left kidney in 38 cases, with tumor size ranging from 1.5 to 19 cm (mean 7 cm). The pathologic grade of the tumor was Grade I in 21, Grade II in 37, Grade III in 15, and Grade IV, in 3 patients. RESULTS: The accuracy of preoperative CT evaluation of the renal vein for presence or absence of tumor thrombus was 96%. The negative predictive value was 97% and the positive predictive value was 92%. Sensitivity was 85% with a specificity of 98%. In two cases we were unable to detect small intrarenal venous thrombus, although this was present on a microscopic level and did not affect surgical resection. A single false-positive CT result occurred secondary to unopacified blood flow from a capsular vein into the affected renal vein, resulting in a small flow void on CT. CONCLUSION: The data show that preoperative staging of the renal vein in the patients with RCC is effectively provided with helical and electron beam CT scanning.

Percutaneous ultrasonic lithotripsy.

Percutaneous renal calculus removal has evolved rapidly over the past 4 years. Percutaneous ultrasonic lithotripsy (PUL), based on access to the kidney via a percutaneous nephrostomy track, consists of fragmentation and removal of calculi under visual nephroscopic control. Clinical experience has proven this modality to be safe, reliable, and effective for treatment of symptomatic renal calculus disease. This article reviews our PUL technique and results.

Percutaneous ultrasonic lithotripsy.

Percutaneous removal of upper urinary tract calculi is a well established procedure. Whereas extraction techniques are effective for small calculi, larger or impacted stones require fragmentation before removal. Percutaneous ultrasonic lithotripsy, endoscopically guided removal of fragments through a percutaneous track, is becoming a widely used method for removal of symptomatic renal and upper ureteral calculi. Radiologic involvement in this method has been essential to its application and success. Experience with over 800 procedures is briefly described, and the highlights of the technique are illustrated.

Primary lymphoma of the bladder.

A case of primary lymphoma of the bladder is presented with a review of the literature. A brief discussion of secondary involvement of the bladder by lymphoma is included.

Dissolution of cholesterol gallstones using methyl tert-butyl ether.

Symptomatic cholelithiasis affects a large segment of the population. Several nonoperative therapeutic alternatives for treatment of these gallstones have recently been developed. We present here the technical aspects and results of gallstone dissolution in 75 patients with the use of methyl tert-butyl ether (MTBE) administered via a small percutaneously placed cholecystostomy catheter. Successful stone dissolution was achieved in 69 patients. The average time required for stone dissolution was 12.4 h over an average of 2.4 days, with the success and rate of dissolution being very dependent on technique. Six patients have developed recurrent gallstones. Future efforts will focus on decreasing the labor intensity of the procedure, dealing with the noncholesterol components of gallstones, and preventing gallstone recurrence.