Efficacy of Extracorporeal Shock Wave Lithotripsy

732 MAGNETIC RESONANCE IMAGING FOLLOWING EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY" Peter Mo Knapp* and John Wo Scott*, Indianapolis, IN (Presentation to be made by Dr" Knapp) The incidence of renal abnormalities following Extracorporeal Shock Wave Lithotripsy (ESWL), as detected by different imaging methods, has been reported to be as high as 74%. To evaluate the acute morphologic changes of the kidney, we performed magnetic resonance imaging (MRI) immediately after ESWL, in 29 patients (33 kidneys)" Multiple Tl and 1'2 weighted axial and coronal images were obtained with a General Electric 1.5 Tesla superconductive magnet equipped scanner. MRI was performed in 6 patients prior to ESWL, demonstrating no abnormalities. Characteristics of patients treated with ESWL included age

~

18 years, normal blood

pressure, no abdominal or flank trauma in the preceeding 6 months, mean stone size of 9.1 mm., and an average of 1,200 shocks administered at 21 KV. Following ESWL, one or more renal abnormalities were demonstrated in 85% of patients, The changes include: 1) low-signal intensity perinephric fat changes in 64%; 2) loss of corticomedullary demarcation in 52%; 3) perirenal or capsular fluid in 15%; 4) subcapsular hematoma in 3%, Postoperatively, no significant changes were identified in blood pressure, serum hemoglobin or creatinine, Similarly, the range of shock waves and KV administered did not correlate with the presence of postoperative changes. The efficacy of ESWL is well established" As a result of this study, acute changes in renal morphology following ESWL can be anticipated in the rnaj ority of patients, While the long term clinical significance of these changes has yet to be determined, we have identified at this institution the development of hypertension in 8.2% of previously normotensive patients treated with ESWL, raising the possibility of a causal relationship. This data, in conjunction with changes in hepatic enzymes, the occurance of clinically apparent perirenal bleedingj and reported pancreatitis convincingly demonstrate that shock waves are not without significant biologic effects as they pass through the body.

COMBINED TREATMENT OF STAGHORN CALCULI BY PERCUTANEOUS NEPHROSTOLITHOTRIPSY AND EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY, Harold Ao Fuselier, Jr" ,M, Do and *Thomas Eo Emerson, M, D,, New Orleans, LA (Presentation to be made by Dr" Fuselier) The Ochsner Medical Institution I s experience using the combined approach of percutaneous ultrasonic nephrostoli thotripsy followed by extracorporeal shock wave lithotripsy (ESWL) in the treatment of infected staghorn calculi has proved effective in the treatment of 8 patients, 2 of whom had solitary kidneys, There were no cases of sepsis with the combined treatment but there was moderate blood loss during the percutaneous procedure

requiring transfusions

in 3 patients.

Renal

function was maintained or improved slightly in all but 1 patient with a solitary kidney" Several patients required more than one ESWL treatment; these treatments were conducted on an outpatient basis. In the majority of patients, stone analysis revealed struvite composition with Proteus species being identified with concomitant bacteriologic testing" Follow up urine sampling has been sterile in all but one patient who has a retained fragment and persistent Pseudomonas bacteruria. No patients have reciuired chemolysiso Despite the morhidity associated with the percutaneous procedures the initial de bulking followed by ESWL is cost effective and associated with minimal postoperative disability and a shorter hospital stay when compared to open renal surgery" Early results based on this limited series have encouraged us to proceed with inpatient percutaneous stone debulking with subsequent outpatient ESWL.

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735

EFFICACY Of EICTRACffiPffiEAL SHOCK WAVE LITHOTRIPSY" Robert Po Gibbons, MD, Roy J" Correa, Jr", MD, George E" Brannen, M:l, Robert Mo Weissman, [v[J, *Donald Go fvl;tcalfe, MD, Robert Lo Calhoun, Ml, *Jeff Frankel, MJ, *Jares Gasparich, MD, Seattle, WA, and Jerry Coles, MD, Anchorage, /lK" (Presentation to be made by Oro Gibbons)

BACK PAIN FDLLCWING EPIDURAL ANESTHESIA FDR EXTRACORPOREAL SJ-JOCK WAVE LITJ-JOTRIPSY {ESWL). ''Peter O" Carey and *Marguerite c. Lippert, Charlottesville, VA. (Presentation to be made by Dr. Carey) After patients have undergone ESWL with epidural anesthesia, a unique syndrome of back pain has been occasionally observed" The pain is located in the low back syrnnetrically over both sacro-iliac joints and extends into both legs to the knees" Such pain has not been observed at our institution in patients who have had epidural anesthesia without ESWL or patients who have had ESWL with general anesthesia, In order to evaluate this phenomenon, 200 patients who underwent ESWL were prospectively evaluated prior to and following ESWL with questionnaires, visual analog pain scales, physical exams, and x-rays" Another group of patients who underwent epidural anesthesia without ESWL were similarly evaluated. The location of the pain over the bilateral SI joints extending into the lower extremities was no greater on the side where the stone v1as treated, but instead was a symuetrical pain, This lower extrenrity to sacro-iliac pain was m::,st corrmonly observed in patients with prior laminectomies, ba.ck trauma, or history of back pain" This unique pain distribution was not observed in the patients who had epidural anesthesia for other reasons

Extracorporeal shock wave lithotripsy (ESWL) has beccne the primary urological treatnent procedure for S.)!TIJtanatic renal and upper ureteral calculi. 100J patients were treated at the Mason Clinic in the first 11 rTDnths that ESWL was available" A total of 1,823 stones were fragmented" M:ist patients received epidural anesthesia" There were approximately 600 males and 4()J fS11ales with an average age of 44 years" 40'/4 of the patients had rrultiple stones, and 134 patients had stones in both kidneys treated on the sare day" i"ost stones were less than 2 on" An average of 1,439 shock waves were given in an average fluoroscopy tirne of 5 minutes" 63% of patients were treated as outpatients" 47 patients required a second ESWL treatnent, and another 62 required rehospitalization; that is, the initial treatment was not successful in 11%" Thirty-six of the 62 rehospitalized patients required srnie type of intervention, usually ureteral manipulation or percutaneous nephrostcmy" Five patients underwent uretero l i thotcmy" The majority of rehospitalized patients not requiring intervention had colic lasting 1 to 3 days" Three patients had perirenal hElllatcmas, one of wilcm required 3 units of blood, two patients had myocardial infarctions, and two patients had urosepsis" There were no deaths" 227 patients had placBTEnt of a ureteral catheter pre-ESWL to aid in localization of poorly visualized calculi or to manipulate upper ureteral stones back into the kidney" 246 patients with a large stone burden, infected urine, or narrowing of the ureter or UPJ had ureteral stents placed prior to ESWLo These were usually left indwelling for 2-4 weeks" Three rmnths following ESWL, 80'/4 of the patients were stone free, 16% had residual but asyrptcmatic fragrents, and 4% had syrptcmatic fragments" The consequence of residual debris in 20% of ESWL-treated patients and the incidence of calculus recurrence awaits further fol low-up"

o

These results will be updated based on our first 2000 patients and presented in May"

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