Extracorporeal shock wave lithotripsy: impact on a large diagnostic radiology department.

Extracorporeal shock wave lithotripsy is a new therapeutic technology that has received instant and widespread acceptance. The history and technical aspects of the procedure are presented, but most importantly, the authors discuss radiology's role and note the importance of management's awareness of the potential impact on departmental fiscal, equipment and personnel resources.     

Extracorporeal shock wave lithotripsy

Urinary tract stones have plagued mankind since ancient times. Until recently, this painful condition was corrected surgically, sometimes with serious complications. This article discusses extracorporeal shock wave lithotripsy (ESWL), a noninvasive treatment that uses shock waves to fragment stones so they can be flushed out of the body through urination. The author describes how urinary tract stones form, their signs and symptoms, different types of ESWL equipment, how the treatment is performed and the recurrence and prevention of urinary tract stones.     

Extracorporeal shock wave lithotripsy: Clinical results

The uroradiological experience with extracorporeal shock wave lithotripsy (ESWL) treatment of over 1,500 urinary calculi is summarized. Percutaneous nephrostomies were needed in 5-50% of ESWL patients depending upon the size and location of stone being treated. Over 25% of percutaneous nephrostomy tracts were subsequently used for other procedures. When staghorn calculi were treated by ESWL, the collaborative efforts of uroradiologists and urologists is mandatory.     

Extracorporeal shock wave lithotripsy and the radiologist

When a hospital acquires a lithotripter it is unlikely that the volume of interventional radiology performed by personnel in that institution will be reduced. On the contrary, a significant increase in workload will probably occur. This will encompass not only interventional procedures on the urinary tract, but will also involve abdominal radiographs, excretory urograms, and so forth. Additional demands on the radiology department in the form of space, equipment, and possibly technical personnel will go hand in hand with an increase in the professional responsibilities of the attending radiologists. Radiologists must prepare themselves and their departments to meet these new responsibilities so that high standards of patient care can be maintained.     

Impact of extracorporeal shock wave lithotripsy on percutaneous stone procedures

Extracorporeal shock wave lithotripsy (ESWL) is now the primary urologic treatment for symptomatic renal calculi; it is responsible for a substantial decrease in percutaneous stone removal procedures. Three hundred patients treated since ESWL became available are compared with the preceding 300 patients who were treated percutaneously. Since it became available, ESWL has been used alone on over 90% of patients. The cost of ESWL (average $7500) is similar to that of percutaneous removal procedures, and it causes less morbidity. Percutaneous techniques are still necessary before ESWL is performed (2%) for patients with a large number of stones or staghorn calculi, especially when there is obstruction. Percutaneous techniques alone (2%) may be necessary, especially if high-grade ureteropelvic junction obstruction is present. After ESWL, percutaneous drainage or retrieval of stone fragments may be required (2%). The need for interventional uroradiology persists, although its role is changing. For optimal patient care, the radiologist should provide the urologist with imaging consultation, radiation protection advice, and continued assistance in the less frequently used, though still essential, percutaneous calculus removal techniques.     

Extracorporeal shock wave lithotripsy: interventional radiologic solutions to associated problems

Among 1,500 patients treated with extracorporeal shock wave lithotripsy, 1,300 had calculi less than 2.5 cm in diameter and 200 had calculi of 2.5 cm or larger. Although most patients did well and required no further radiologic intervention, 178 interventional radiologic procedures were performed. Urinary tract obstruction often developed in patients with large stones when the collecting system filled with stone fragments (steinstrasse). Nephrostomy was performed in 5.3% of the total patient population and in 29% of the patients with stones measuring 2.5 cm or more. Only 1.8% of the patients with calculi smaller than 2.5 cm required radiologic intervention. When the obstructed collecting system could not be crossed with conventional angiographic techniques, the stone fragments were removed through a percutaneous nephrostomy tract either by flushing or by suctioning with a pulsating water jet.     

Extracorporeal shock wave lithotripsy of calcified gallstones. Work in progress

Thirty-eight patients with calcific cholecystolithiasis underwent extracorporeal shock wave lithotripsy (ESWL) of the gallbladder on an outpatient basis. Twenty-two (60%) patients had fragments smaller than 3 mm on follow-up ultrasound (US) studies after an average of 13,450 shock waves and four lithotripsy sessions. Nineteen of these 22 patients were followed up for an average of 18 weeks, and only three were found to be free of residual fragments at US. The other three patients were lost to follow-up. Sixteen patients are still undergoing biliary ESWL. Comparison of calcified and noncalcified gallbladder calculi revealed that calcified stones required 50% more shock waves for successful fragmentation, fragments cleared considerably more slowly from the gallbladder, and patients had a higher frequency of acute pancreatitis (5% vs 2%) and transient hematuria (8% vs 3%). Stones with dense homogeneous calcification required significantly fewer shock waves for successful fragmentation than stones with calcific lamination. ESWL can be applied occasionally in patients with calcific cholecystolithiasis if an alternative to surgery is required, but success has been limited.     

Choledocholithiasis: treatment with extracorporeal shock wave lithotripsy

In a patient with choledocholithiasis, a duodenal diverticulum precluded endoscopic retrograde bile duct cannulation. A transhepatic catheter was used to opacify the bile ducts and to guide the endoscopic sphincterotome into the major duodenal papilla. Because limited sphincterotomy did not allow extraction or spontaneous passage of the common duct stones, extracorporeal lithotripsy was performed. Following fragmentation, the stones passed spontaneously and without complications.     

Extracorporeal shock wave lithotripsy and stents: Fluoroscopic observations and a hypothesis on the mechanisms of stent function

Fluoroscopic observations made during voiding cystography on 5 patients suggest that a possible reason that double-J ureteric stents are effective in the management of steinstrasse after extracorporeal shock wave lithotripsy (ESWL) is because they allow free fluid reflux from the bladder to the kidney. This reflux in turn triggers active peristalsis down the ureter. These observations may help us in understanding the function of ureteric stents, and suggest that stents should only have side holes at their proximal and distal ends; no side holes should be present along the shaft of the stent. Stone fragments are propelled down the ureter around the stent, hence narrow stents are preferred.     

Extracorporeal shock wave treatment of humeral nonunion: a case report

Abstract Fracture of the humerus represents a common problem among the young and elderly populations. Although humerus fractures usually heal uneventfully, nonunions can sometimes occur. We present a case of humeral nonunion managed with shock wave therapy in the outpatient setting. A 62-year-old woman with a closed comminuted fracture of the proximal third of the humerus came to our attention 6 months after the trauma with a hypertrophic nonunion. Radiographs showed a hypertrophic callus with a fracture gap of 4 mm. We performed ten shock wave treatments in the outpatient department, with an interval of 60 days between each single treatment. Each session consisted of 2000 impulses at 0.86 mJ/mm² applied in two planes. No anesthesia was given during the treatment. The patient received a sling to support the treated arm during the first days following each treatment. Follow-up assessment by radiographic and physical examination, performed after 4 weeks and at 3, 6, 12, 18 and 24 months, showed complete bony union and cortical bridging, achieved at the end of the treatment. We believe that this method is a safe and effective alternative to surgery for the treatment of chronic hypertrophic nonunions. Moreover, in case such treatment is unsuccessful, subsequent surgery is not precluded.     

Renal obstruction from persistent struvite stone matrix: a complication of extracorporeal shock wave lithotripsy

Struvite calculi occurring in patients with chronic urinary tract infections consist of an inorganic component of magnesium ammonium phosphate crystals and an underlying organic mucopolysaccharide matrix. Shock waves used to destroy these stones during extracorporeal shock wave lithotripsy (ESWL) therapy may affect the inorganic and organic components of the stone differently. In a 26-year-old woman, renal obstruction resulted from retained struvite stone matrix after ESWL therapy.     

Extracorporeal shock wave treatment for shoulder calcific tendonitis: a systematic review

The treatment of patients with calcific tendonitis is typically conservative, including physical therapy, iontophoresis, deep friction, local or systemic application of noninflammatory drugs, needle irrigation–aspiration of calcium deposit, and subacromial bursal steroid injection. If the pain becomes chronic or intermittent after several months of conservative treatment, arthroscopic and open procedures are available to curette the calcium deposit, and additional subacromial decompression can be performed if necessary. As an alternative, minimally invasive extracorporeal shock wave therapy (ESWT) has been postulated to be an effective treatment option for treating calcific tendinitis of the shoulder, before surgery. Herein we discuss the indications, mechanism of therapeutic effect, efficacy of treatment, and complications after ESWT application.     

Digital archive center: implementation for a radiology department.

OBJECTIVE. In this article, we describe the implementation of a digital archive center for a radiology department in a 700-bed teaching hospital. MATERIALS AND METHODS. The archive center consists of two identical archive systems, each comprising five components: an archive server, a data-base server, an optical disk library, a stand-alone optical disk drive, and a communication network. An image management system controls the image traffic from acquisition devices to display stations. A fault-tolerant mechanism was built into the archive center to achieve a 100% uptime. RESULTS. The center has been in operation for over 6 months. We have not experienced a single total system failure during this period. It currently archives all digital images from three MR units and four CT scanners and selected images from three computed radiographic systems and two laser film digitizers. The center archives between 1.5 and 2.0 gigabytes of images per workday. CONCLUSION. With its built-in fault-tolerant mechanism, we believe that the implemented archive center is very reliable and is suitable for a radiology department to archive its digital images.     

Renal stone disease treated with extracorporeal shock wave lithotripsy: short-term observations in 100 patients

The immediate posttreatment findings are described for 100 patients who underwent extracorporeal shock wave lithotripsy (ESWL) for renal stone disease. Excretory urography was performed both before and 24-72 hours after ESWL. In 21 patients, stones were completely disintegrated, and stone fragments were passed rapidly. Stones were fragmented but not passed entirely within 24-72 hours in 76 patients. There was no appreciable effect on stones in three patients. In nine of 27 patients who had mild to severe ureteral obstruction caused by stone fragments, relief procedures (retrograde ureteral manipulation or percutaneous stone extraction) were necessary. Overall, 70 patients experienced successful stone disintegration without complications. Continued investigation is needed to determine prevalence of residual calculi, reversibility of acute effects of ESWL on the kidney, and possible development of late hypertension.