Heart Rate Variability Change Before and After Hemodialysis is Associated with Overall and Cardiovascular Mortality in Hemodialysis.

Low heart rate variability (HRV) has been recognized to correlate with adverse cardiovascular (CV) outcomes in hemodialysis (HD) patients. It has been reported that HRV might be improved after HD, but whether the improved HRV after HD predicts a better CV prognosis remains to be determined. This study examined the ability of the change in HRV before and after HD in predicting overall and CV mortality in HD patients. This study enrolled 182 patients under maintenance HD. HRV was examined to assess changes before and after HD. The change in HRV (ΔHRV) was defined as post-HD HRV minus pre-HD HRV. During a median follow-up period of 35.2 months, 29 deaths (15.9%) were recorded. Multivariate analysis showed that decreased ΔLF% was associated with increased overall (hazard ratios [HR], 0.978; 95% confidence interval [CI], 0.961-0.996; p = 0.019) and CV mortality (HR, 0.941; 95% CI, 0.914-0.970; p < 0.001), respectively. Moreover, adding ΔLF% to a clinical model provided an additional benefit in the prediction of overall (p = 0.002) and CV mortality (p < 0.001). HRV change before and after HD (ΔHRV) is an useful clinical marker, and it is stronger than HRV before HD in predicting overall and CV mortality.

Laparoscopic cryoablation of renal masses.

Laparoscopic cryoablation seems to be an effective treatment modality for small peripheral renal tumors. The technique is minimally invasive, has a rapid learning curve, results in minimal blood loss and morbidity, and, to date, has demonstrated precise reliable ablation of small renal neoplasms. Long-term follow-up is necessary to confirm the absence of local tumor recurrence or distant or port-site metastases.

Laparoscopic renal cryoablation in 32 patients.

OBJECTIVES: Laparoscopic renal cryoablation is a developmental minimally invasive nephron-sparing treatment alternative for highly select patients with small renal tumors. We present our evolving experience with this procedure. METHODS: Thirty-two patients (34 tumors) with a mean tumor size of 2.3 cm on preoperative computed tomography underwent laparoscopic renal cryoablation. As dictated by the tumor location, cryoablation was performed by either the retroperitoneal (n = 22) or the transperitoneal (n = 10) laparoscopic approach using real-time ultrasound monitoring. A double freeze-thaw cycle was routinely performed. RESULTS: The mean surgical time was 2.9 hours, cryoablation time 15.1 minutes, and blood loss 66.8 mL. For a mean intraoperative ultrasonographic tumor size of 2 cm, the mean cryolesion size was 3.2 cm. The hospital stay was less than 23 hours in 22 (69%) of 32 patients. Sequential magnetic resonance imaging scans demonstrated a gradual contraction in the mean diameter of the cryolesions. Of the 20 patients who underwent a 1-year follow-up magnetic resonance imaging scan, the cryoablated tumor was no longer visible in 5. Of note, 23 patients have now undergone a 3 to 6-month follow-up computed tomography-directed biopsy of the cryoablated tumor site; the biopsy was negative for cancer in all 23 patients. No evidence of local or port-site recurrence was found during a mean follow-up of 16.2 months. CONCLUSIONS: Critical long-term data regarding laparoscopic renal cryoablation, a developmental technique, are awaited. However, our initial experience is cautiously optimistic. Despite its significant potential for false-negative results, it is encouraging that the follow-up computed tomography-directed needle biopsies at 3 to 6 months were negative for cancer in 23 of 23 patients.

Survey of neuromuscular injuries to the patient and surgeon during urologic laparoscopic surgery.

OBJECTIVES: Laparoscopy may be complicated by neuromuscular injuries, both to the patient and to the surgeon. We used a survey to estimate the incidence of these injuries during urologic laparoscopic surgery, to assess risk factors for these injuries, and to determine preventive measures. METHODS: A survey of neuromuscular injuries associated with laparoscopy submitted to 18 institutions in the United States was completed by 18 attending urologists from 15 institutions. RESULTS: From among a total of 1651 procedures, there were 46 neuromuscular injuries in 45 patients (2.7%), including abdominal wall neuralgia (14), extremity sensory deficit (12), extremity motor deficit (8), clinical rhabdomyolysis (6), shoulder contusion (4), and back spasm (2). Neuromuscular injuries were twice as common with upper retroperitoneal as with pelvic laparoscopy (3. 1% versus 1.5%). Among patients with neuromuscular injuries, those with rhabdomyolysis were heavier (means 91 versus 80 kg) and underwent longer procedures (means 379 versus 300 minutes), and those with motor deficits were older (means 51 versus 42 years of age). Of the surgeons, 28% and 17% reported frequent neck and shoulder pain, respectively. CONCLUSIONS: Although not common, neuromuscular injuries during laparoscopy do contribute to morbidity. Abdominal wall neuralgias, injuries to peripheral nerves, and joint or back injuries likely occur no more frequently than during open surgery, but risk of rhabdomyolysis may be increased. Positioning in a partial rather than full flank position may reduce the incidence of some injuries. Measures to reduce neuromuscular strain on the surgeon during laparoscopy should be considered.

Laparoscopic retroperitoneal lymph node dissection for clinical stage I nonseminomatous germ cell testicular tumors.

OBJECTIVES: To assess retrospectively whether laparoscopic retroperitoneal lymph node dissection (RPLND) in patients with clinical Stage I nonseminomatous germ cell testicular tumor (NSGCT) provides useful pathologic staging information on which subsequent management can be based. Approximately 30% of patients with clinical Stage I NSGCT will have pathologic Stage II disease. METHODS: A retrospective review of 29 patients with clinical Stage I NSGCT who underwent transperitoneal laparoscopic RPLND by a single surgeon was performed. Selection criteria included the presence of embryonal carcinoma in the primary tumor or vascular invasion. A modified left (n = 18) or right (n = 11) template was used. RESULTS: Positive retroperitoneal nodes were detected in 12 (41%) of 29 patients. Ten of these patients received immediate adjuvant platinum-based chemotherapy, and 2 patients refused chemotherapy. The nodes were negative in 1 7 (59%) of 29 patients; all but 2 patients (one with recurrence in the chest, the other with biochemical recurrence) have undergone observation. No evidence of disease recurrence has been found in the retroperitoneum of any patient (follow-up range 1 to 65 months). Prospectively, the dissection was limited if grossly positive nodes were encountered; therefore, the total number of nodes removed was significantly different if the nodes were positive or negative (14 +/- 2 and 25 +/- 3, respectively; P <0.004). Two patients required an open conversion because of hemorrhage. Complications included lymphocele (n = 1) and flank compartment syndrome (n = 1). CONCLUSIONS: Laparoscopic RPLND is a feasible, minimally invasive surgical alternative to observation or open RPLND for Stage I NSGCT. Disease outcomes are favorable to date. Longer follow-up in a larger series is necessary to determine therapeutic efficacy.

Laparoscopic versus open pyeloplasty: assessment of objective and subjective outcome.

PURPOSE: We determine the subjective and objective durability of laparoscopic versus open pyeloplasty. MATERIALS AND METHODS: From August 1993 to April 1997, 42 patients underwent laparoscopic pyeloplasty (laparoscopy group) with a minimum clinical followup of 12 months (mean 22). Subjective outcomes and objective findings were compared to those of 35 patients who underwent open pyeloplasty (open surgery group) from August 1986 to April 1997 with a minimum clinical followup of 12 months (mean 58). We assessed clinical outcome based on responses to a subjective analog pain and activity scale. In addition, radiographic outcome was assessed based on the results of the most recent radiographic study. RESULTS: Of the 42 laparoscopy group patients 90% (38) were pain-free (26, 62%) or had significant improvement in flank pain (12, 29%) after surgery. Two patients had only minor improvement and 2 had no improvement in pain. Surgery failed in only 1 patient with complete obstruction. A patent ureteropelvic junction was demonstrated in 98% (41 of 42 patients) of the laparoscopy group on the most recent radiographic study (mean radiographic followup 15 months). Of the 35 open surgery group patients 91% were pain-free (21, 60%) or significantly improved (11, 31%) after surgery. One patient had only minor improvement and 2 were worse. CONCLUSIONS: Pain relief, improved activity level and relief of obstruction outcomes are equivalent for laparoscopic and open pyeloplasty.

Feasibility of total intravesical endoscopic surgery using mini-instruments in a porcine model.

BACKGROUND AND OBJECTIVES: The aim of minimally invasive approaches to vesicoureteral reflux, such as endoscopic trigonoplasty, is to lower the morbidity of open procedures without compromising the results. Initial successes have not been sustained, mainly because of trigonal splitting, which results in the ureteral orifices returning to their preoperative positions. This study was designed to address trigonal splitting by mobilizing the ureters before repositioning them and to evaluate the feasibility of accomplishing this intravesically with 2- to 3-mm endoscopic mini-instruments. METHODS: Bilateral vesicoureteral reflux was surgically created in 10 minipigs. After radiologic confirmation of success 4 weeks later, modified trigonoplasty was performed by endoscopic intravesical mobilization of both ureters and incision of the trigonal mucosa using 2-mm instruments. The ureteral orifices were then advanced toward the midline and sutured in place. The initial surgical techniques were modified to permit the entire procedure to be performed endoscopically in the last four minipigs. Cystograms and intravenous urograms were obtained 4 weeks later. RESULTS: Two minipigs died postoperatively. Six of the remaining eight had persistent reflux, including three of the four in the group treated completely by endoscopic means. None of the dissected ureters showed evidence of stricture or necrosis. CONCLUSIONS: Although the procedure was not successful in correcting reflux in this model, this study demonstrates the feasibility of endoscopic ureteral mobilization. With current instrumentation, there is no significant technical obstacle to complete intravesical endoscopic surgery, including ureteral reimplantation.

Utility of the harmonic scalpel for laparoscopic partial nephrectomy.

Laparoscopic partial nephrectomy (LPN) remains a technically challenging procedure largely because of the lack of methods for obtaining consistent parenchymal hemostasis. The objective of this study was to determine if the extent of resection influences the ability of the harmonic scalpel to achieve hemostasis and to define the cases in which the harmonic scalpel is appropriate for LPN. Thirty LPNs were performed in a 25-kg domestic pig model. The blunt blade of the laparoscopic harmonic scalpel (LaparoSonic Coagulating Shears; Ethicon Endo-Surgery, Cincinnati, OH) at power level 5 was used to divide the parenchyma. Control of the renal hilar vessels was not obtained. Three standardized types of resections were performed: I = peripheral wedge biopsy; II = upper- or lower-pole nephrectomy; and III = heminephrectomy. Bleeding was graded on a scale from 0 to 4: 0 = no hemostasis; 1 = steady bleeding; 2 = moderate bleeding; 3 = parenchymal oozing; and 4 = dry. Hemostasis grades of 2 or less were clinically significant bleeding necessitating supplemental coagulation. The mean hemostasis scores showed a significant (P < 0.02) trend toward inadequate hemostasis with increasing extent of resection: 3.3 for Type I, 3.0 for Type II, and 2.4 for Type III. The percent of kidneys with grade 2 bleeding or worse was 9% for Type I surgery, 25% for Type II, and 57% for Type III. Successful hemostasis with the harmonic scalpel correlates with the extent of parenchymal resection in the porcine model. Most wedge excisions can be done with the harmonic scalpel alone, whereas larger resections necessitate supplemental coagulation. On the basis of this study, heminephrectomies with the harmonic scalpel are not recommended because of the high incidence of significant hemorrhage.

Laparoscopic renal biopsy.

BACKGROUND: Renal biopsy continues to be a pivotal tool and frequently indispensable diagnostic procedure in the clinical assessment of proteinuria and or unexplained renal disease. Laparoscopic renal biopsy has recently been reported as an alternative to open renal biopsy. METHODS: Thirty-two patients who had proteinuria and/or renal insufficiency underwent laparoscopic renal biopsy at our center. The indications for biopsy included failed percutaneous biopsy (N = 3), morbid obesity (14), solitary kidney (5), chronic anticoagulation/coagulopathy (6), religious consideration (refusal of potential blood transfusion) (2), multiple bilateral renal cysts and body habitus (1 case each). The kidney was approached via a laparoscopic retroperitoneal route (retroperitoneoscopy) using a two port technique. The lower pole of the kidney was localized using blunt dissection, laparoscopic cup biopsies were performed, and hemostasis was achieved using standard techniques. RESULTS: All biopsies were successfully completed laparoscopically with sufficient tissue obtained for histopathological diagnosis in all cases. Mean estimated blood loss was 25.9 ml (range 5 to 100). None of the patients required parenteral narcotics during the perioperative period. Operative time ranged from 0.8 to 3.0 hours (mean 1.5). Mean hospital stay was 1.7 days (range 0 to 7). Sixteen patients were treated as outpatients. Patients returned to normal activity at a mean of 1.7 weeks (range 0.3 to 3.0) postoperatively. In one patient, the spleen was inadvertently biopsied without consequence. An additional patient developed a postoperative 300 cc perinephric hematoma that resolved without the need for intervention. One postoperative mortality occurred on postoperative day seven secondary to a perforated peptic ulcer in a patient undergoing high-dose steroid therapy for lupus nephritis. CONCLUSION: Laparoscopic renal biopsy is a safe, reliable, minimally invasive alternative to open renal biopsy for patients in whom a closed percutaneous approach is either a relative or absolute contraindication, which can be performed on an outpatient basis.

Laparoscopic subcapsular nephrectomy.

A 26-year-old patient with end-stage renal disease secondary to vesicoureteral reflux and recurrent pyelonephritis was referred for bilateral native nephrectomy. A transperitoneal laparoscopic approach was used. Extremely dense fibrosis was encountered around the left kidney during the dissection. A left laparoscopic subcapsular nephrectomy and a right extracapsular nephrectomy were performed. The indications and surgical technique for laparoscopic subcapsular nephrectomy are discussed.

Laparoscopic pyeloplasty. Indications, technique, and long-term outcome.

Laparoscopic pyeloplasty is one of several minimally invasive treatment options for UPJ obstruction. In fact, several endoscopically and fluoroscopically controlled methods of incising the obstructed UPJ are now available that are significantly less invasive and less morbid in comparison with open pyeloplasty. However, the long-term success rates of these incisional techniques are less than the rates reported for open pyeloplasty. Several causes of obstruction may be present in the primarily obstructed UPJ, including kinking or compression related to crossing vessels or intrinsic narrowing at the UPJ. One potential reason for the inferior success rates of incisional methods in comparison with open pyeloplasty is that the former techniques address the intrinsically narrowed UPJ but may not address extrinsic problems such as kinking of the ureter associated with fibrotic bands or compression from crossing vessels. Laparoscopic pyeloplasty addresses all potential causes of obstruction. Any fibrotic bands kinking the ureter are divided, and the ureter is spatulated through the level of the UPJ prior to completion of the anastomosis. If a crossing vessel is encountered, a dismembered pyeloplasty is performed, the ureter and renal pelvis are transposed to the opposite side of the vessels, and the anastomosis is completed. An additional disadvantage of incisional techniques is the significant risk of hemorrhage following incision of the UPJ, with as many as 3% to 11% of patients requiring blood transfusion. Hemorrhage may occur owing to an errant anterior incision, the presence of a crossing vessel, incision into the renal parenchyma adjacent to the UPJ, or as the result of bleeding from the percutaneous access site. In contrast, mean estimated blood loss in the authors' series of 57 laparoscopic pyeloplasties was 139 mL, and none of the patients required blood transfusion. Although it is more morbid in comparison with retrograde or fluoroscopically controlled endopyelotomy, laparoscopic pyeloplasty seems at least comparable to antegrade percutaneous endopyelotomy in terms of the length of hospitalization and patient convalescence. Laparoscopic pyeloplasty, however, offers a higher success rate than with incisional techniques, not only from a radiographic standpoint but from a subjective standpoint as determined by the results of the analogue pain and activity questionnaire. The major disadvantage of laparoscopic pyeloplasty is the need for proficiency in laparoscopic techniques and for a longer operative time. As a result, the literature on laparoscopic pyeloplasty consists primarily of small series. Janetschek and co-workers reported on a series of 17 patients who underwent laparoscopic pyeloplasty, including 14 via a transperitoneal approach and 3 via a retroperitoneal approach. Procedures performed included ureterolysis alone, dismembered pyeloplasty, and nondismembered (Fenger) pyeloplasty. "Fenger-plasty" is similar to Y-V pyeloplasty and is performed by incising the UPJ longitudinally and closing the incision transversely in a Heineke-Mikulicz fashion. Janetschek and colleagues reported a 100% success in the eight patients who underwent dismembered pyeloplasty but believed that this technique was too cumbersome and should be reserved for patients with long stenoses, dorsally crossing vessels, or large renal pelvis. Because two of the four patients undergoing ureterolysis alone failed treatment, Janetschek and colleagues have abandoned this technique. They now prefer the Fenger-plasty technique, even in the setting of ventrally crossing vessels, because the technique can be performed quickly with one to three sutures, and the anastomosis can be sealed with fibrin glue and a flap of Gerota's fascia. Their experience with this technique, however, remains relatively limited. Technologic advances such as the Endostitch device have facilitated reconstructive laparoscopic procedures such as pyeloplasty. (ABSTRACT TRUNCATED)

Stereotactic mechanical percutaneous renal access.

Obtaining accurate percutaneous renal access when treating intrarenal disease requires substantial skill. Robotic devices have been used in a variety of surgical applications and have been successful in facilitating percutaneous puncture while improving accuracy. Laboratory models of robotic devices for percutaneous renal access have also been developed. However, several technical hurdles need to be addressed. One relates to the device-patient interface. As a first step in creating a complete robotic system, a mechanical arm (PAKY) with active translational motion for percutaneous renal access has been developed and clinically assessed. The PAKY consists of a passive mechanical arm mounted on the operating table and a radiolucent needle driver that uses a novel active translational mechanism for needle advancement. The system utilizes real-time fluoroscopic images provided by a C-arm to align and monitor active needle placement. In vitro experiments to test needle placement accuracy were conducted using a porcine kidney suspended in agarose gel. Seven copper balls 3 to 12.5 mm diameter were placed in the collecting system as targets, and successful access was confirmed by electrical contact with the ball. The PAKY was then used clinically in nine patients. The number of attempts, target calix location, calix size, and time elapsed were evaluated. In the in vitro study, successful needle-ball contact occurred the first time in all 70 attempts, including 10 attempts at the 3-mm balls. Clinically, percutaneous access to the desired calix was attained on the first attempt in each case. The mean target calix diameter was 14.7 mm (range 7-40 mm). The mean time elapsed while attempting access was 8.2 minutes. No perioperative complications attributable to needle access occurred. Early experience indicates that the PAKY provides a steady needle holder and an effective and safe end-effector for percutaneous renal access. This device may provide the mechanical platform for the development of a complete robotic system capable of creating percutaneous renal access.

Laparoscopic renal surgery in patients at high risk for intra-abdominal or retroperitoneal scarring.

Prior open abdominal or renal surgery has been considered a relative contraindication to laparoscopic surgery because of the likelihood of adhesion formation and perinephric scarring, which results in difficulty obtaining access to the peritoneal cavity and during surgical dissection. The purpose of this study was to examine the feasibility and morbidity of laparoscopic renal surgery in patients at high risk for intra-abdominal or retroperitoneal scarring. Twenty-four patients who underwent laparoscopic renal surgery at our institution gave a history of significant open abdominal or renal surgery. Seven patients had undergone prior open extraperitoneal (N = 6) or percutaneous (N = 1) renal procedures, 10 patients had undergone prior open laparotomy for various reasons, and 7 patients had undergone open pelvic surgery. The mean interval from the prior operation to laparoscopic renal surgery was 16.5 years (range 0.3-44 years). Operative time, estimated blood loss, incidence of complications, perioperative parenteral narcotic use, length of hospitalization convalescence, and degree of intra-abdominal and retroperitoneal scarring were assessed. Patients who developed complications were compared with patients who did not. No difficulty was encountered while obtaining initial access to the peritoneal cavity or retroperitoneal space. No bowel or visceral injuries occurred during Veress needle or trocar placement. The laparoscopic procedure was completed successfully in all cases. The mean operative time was 4.3 (range 2.0-10.9) hours. The mean estimated blood loss was 266 mL (range 50-1200 mL). There were eight complications (overall complication 33%) including three major and five minor complications. Patients who developed complications had a higher total scarring score that those who did not (p = 0.01). For experienced laparoscopic surgeons, laparoscopic renal surgery in patients who have a history of open abdominal or renal surgery can be successful. Access via the transperitoneal or retroperitoneal route can be obtained safely, and the procedure usually can be performed in a timely fashion. However, a relatively high perioperative complication rate can be expected, particularly for those patients with significant intraperitoneal and retroperitoneal scarring.

Retroperitoneoscopic renal biopsy in extremely obese patients.

OBJECTIVES: Retroperitoneoscopic renal biopsy can be technically challenging in extremely obese patients because of loss of surgical landmarks and difficulty in identifying the kidney within retroperitoneal adipose tissue. We present our experience with retroperitoneoscopic renal biopsy in extremely obese patients and describe our surgical technique. METHODS: We performed retroperitoneoscopic renal biopsies on 8 extremely obese patients (body mass index greater than 40). Mean patient weight was 144.3 kg. Three patients presented with acute renal failure and 5 presented with nephrotic range proteinuria. Retroperitoneoscopic renal biopsy was indicated based on extreme obesity alone in 3 patients, 2 patients had failed previous attempts at percutaneous biopsy, 1 patient had a solitary kidney, 1 patient required chronic anticoagulation, and 1 patient was a Jehovah's Witness. Intraoperative ultrasonography and an anatomic approach facilitated the dissection and identification of the kidney. RESULTS: All eight retroperitoneoscopic renal biopsies were completed successfully without complication and all patients were discharged within 24 hours of the procedure. Sufficient tissue for pathologic diagnosis was obtained in all cases. Mean operating room time was 153 minutes and mean estimated blood loss was 71 mL. The patients returned to normal activity at a mean of 1.8 weeks. CONCLUSIONS: With the use of intraoperative ultrasonography and a systematic, anatomic approach, retroperitoneoscopic renal biopsy can be successfully completed in extremely obese patients. This procedure can be reliably performed on an outpatient basis with minimal morbidity and should be considered a viable alternative to open renal biopsy.

Prospective evaluation of fine needle aspiration of small, solid renal masses: accuracy and morbidity.

OBJECTIVES: To determine the accuracy and clinical utility of fine needle aspiration (FNA) of small, solid renal masses. METHODS: A total of 25 patients with small (less than 5.0 cm), solid, clinically localized renal masses were prospectively identified and evaluated with computed tomography guided FNA with analysis for presence of malignant cells and determination of nuclear grade. The final pathologic findings were used for comparison in each case. All patients had renal cell carcinoma and were managed with radical or partial nephrectomy; 3 had low-grade lesions (Fuhrman's grade 1/4), 2 had high-grade lesions (Fuhrman's grade 4/4), and all other patients had intermediate-grade lesions (Fuhrman's grade 2/4 or 3/4) on final histopathologic assessment. RESULTS: Overall, 10 aspirations yielded diagnostic malignant cells, and 9 were read as rare as rare atypical cells suspicious for malignancy. The remainder were negative (n = 6). Correlation with final nuclear grade was observed in eight instances and discordance in two instances. Subcapsular hematomas were observed at the time of surgery in 10 patients, but in no instance was the operation adversely affected. CONCLUSIONS: The diagnostic yield of FNA of small, solid renal masses appears to be too low to justify the potential morbidity of the procedure.

Laparoscopic pyeloplasty: experience with the initial 30 cases.

PURPOSE: We assessed the intermediate effectiveness of laparoscopic pyeloplasty in the treatment of the obstructed ureteropelvic junction. MATERIALS AND METHODS: A total of 30 pyeloplasties was performed for symptomatic ureteropelvic junction obstruction (24 primary and 6 secondary cases). Two separate types of reconstruction were performed, that is dismembered (26 patients) and Y-V (4) pyeloplasty. All patients were followed with excretory urography or diuretic renography. Moreover, factors affecting the learning curve (surgical technique, prior laparoscopic experience and cause of obstruction) were evaluated. RESULTS: A lower pole segmental renal vessel was found at the ureteropelvic junction in 18 patients (60%). Operative time ranged from 2.25 to 8.0 hours (mean 4.5). Postoperative morbidity (mean narcotic requirement 37.3 mg. morphine sulfate, mean hospital stay 3.5 days and convalescence 3 weeks) was minimum. At radiographic followup (mean 16.3 months, range 4 to 73) 97% of the patients demonstrated a patent ureteropelvic junction and resolution of or substantial decrease in hydronephrosis. CONCLUSIONS: In the hands of an experienced laparoscopist, outcomes indicate that laparoscopic pyeloplasty shows success similar to that of open pyeloplasty but longer term outcomes must be assessed.

Extracorporeal shock wave lithotripsy for lower pole calculi: long-term radiographic and clinical outcome.

PURPOSE: We evaluated the efficacy of extracorporeal shock wave lithotripsy (ESWL) for lower pole calculi regarding immediate and long-term radiographic and clinical outcomes. MATERIALS AND METHODS: A total of 206 patients with isolated lower pole calculi in 220 renal units underwent ESWL for stones 4 to 625 mm2 (mean 88). Clinical and radiographic followup was obtained at 1 month and every 6 to 12 months thereafter. An initial stone-free rate was determined, as was the subsequent radiographic outcome. Clinical outcome with regard to a symptomatic episode or requiring intervention was also determined. Kaplan-Meier estimates of the probabilities of these outcomes with time were developed. RESULTS: Of the 206 patients 99 (48%) were rendered stone-free by 1 month after ESWL. Another 13 patients (6.3%) spontaneously became stone-free within another 1 to 95 months (mean 17.5). Of the remaining patients residual stones were decreased, stable or increased in 13 (6.3%), 71 (34%) and 10 (4.8%), respectively, after 1 to 91 months (mean 14.5). Among all 206 patients 180 (87.4%) remained asymptomatic for 1 to 99 months, while 7 (3.4%) suffered a symptomatic episode requiring medical attention 1 to 40 months (mean 21.1) after ESWL and 19 (9.2%) required intervention after 1 to 91 months (mean 23.9). Kaplan-Meier estimates of the probabilities of a symptomatic episode or requiring intervention at 5 years were 0.24 and 0.52, respectively. CONCLUSIONS: ESWL is the initial treatment of choice for lower pole calculi smaller than 2 cm.2 because the stone-free rate is comparable to that for stones at other caliceal locations and, perhaps more importantly, the risk of a symptomatic episode or requiring secondary intervention is low even in the setting of residual fragments.