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.

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.

Role of endothelium-derived relaxing factor in the maintenance of renal blood flow in a rodent model of chronic hydronephrosis.

OBJECTIVES: To define the role of endothelium-derived relaxing factor (EDRF) in the regulation of renal hemodynamics in the hydronephrotic kidney. METHODS: Experiments were performed in control rats and in rats that had undergone unilateral ureteral ligation 6 weeks before. Renal blood flow was monitored before and after inhibition of EDRF synthesis in the control and hydronephrotic animals. Videomicroscopy was also performed in hydronephrotic animals to observe directly the effect of inhibition of EDRF synthesis on the renal microcirculation. RESULTS: Inhibition of EDRF synthesis resulted in a 61% decrease in renal blood flow in the control animals compared with only a 27% decrease for the hydronephrotic animals. The videomicroscopy studies demonstrated that inhibition of EDRF synthesis results in significant vasoconstriction of the preglomerular and postglomerular resistance vessels. CONCLUSIONS: Although EDRF continues to play a significant role in the maintenance of renal blood flow in the chronically obstructed kidney, EDRF synthesis by the renal vascular endothelium may be reduced in this setting, contributing to ischemic renal atrophy.

Testicular cancer in association with developmental renal anomalies and hypospadias.

OBJECTIVES: To characterize the clinical, pathologic, and genetic aspects of patients with a previously undescribed phenotype of testicular germ cell tumors associated with renal hypoplasia or agenesis and urethral hypospadias. METHODS: Review of clinical and pathologic findings and genetic analysis of constitutional and tumor DNA for mutations of the Wilms' tumor suppressor gene (WT1). RESULTS: Clinical findings suggest that this phenotype is distinct from other syndromes associated with renal anomalies and that the associated testicular tumors are histologically and clinically similar to those that occur sporadically. No karyotypic abnormalities, loss of heterozygosity, or mutations in the zinc finger domains (exons 7-10) of WT1 were observed in 5 patients with this phenotype. CONCLUSIONS: The phenotype of testicular germ cell tumor, developmental renal anomalies, and urethral hypospadias constitutes a discrete syndrome caused by a gene distinct from WT1.

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.

Diagnostic tunica vaginoscopy in a rodent model of testicular torsion.

OBJECTIVES: To evaluate the effectiveness of percutaneous endoscopy of the tunica vaginalis for identifying testicular torsion in a rodent model. METHODS: One testis was randomly selected in 10 Wistar rats weighing 500 to 600 g. Following 2 hours of 720 degree torsion, bilateral percutaneous endoscopy of the tunica vaginalis was performed by a blinded investigator utilizing a 70 degree cystoscope lens through a single midline 3 to 4 mm scrotal cutdown incision. RESULTS: Using this technique, the blinded investigator was able to identify the torsed testis rapidly in every case, which was distinguished by its cyanotic color and by the size and color of the testicular surface vessels. CONCLUSIONS: Tunica vaginoscopy is a simple, accurate, rapidly performed, minimally invasive, diagnostic technique in this experimental model of testicular torsion.

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 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 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)

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.

Thirteen patients underwent laparoscopic dismembered pyeloplasty at our institution. The operative time ranged from 4 to 8 (mean 5.4) hours with minimal blood loss. Two patients developed transient edema necessitating temporary drainage. The mean requirement for morphine postoperatively was 32 mg. At a mean follow-up of 13 months, all patients demonstrated both symptomatic and radiographic relief of obstruction. Laparoscopic dismembered pyeloplasty appears to be an effective minimally invasive alternative to treat symptomatic ureteropelvic junction obstruction.

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.

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 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.

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.

Analysis of biogenic amines and their metabolites in biological tissues and fluids by gas chromatography-negative ion chemical ionization mass spectrometry (GC-NICIMS).

GC-NICIMS has been employed in the analysis of biogenic amines and their metabolites in human urine and human, bovine and porcine aqueous and vitreous humour. Several new chemical derivatization procedures have been developed in order to analyse these compounds. Concentrations of octopamines and synephrines were determined in urine from treated and untreated hypertensive subjects and normotensive individuals; there were no significant differences in concentrations of these metabolites between these groups. Human urine contained several dihydroxy-phenylethylamines which have not been reported as natural metabolites before and also 5- and 6-hydroxydopamine in relatively large amounts. Aqueous and vitreous humour contained very low quantities of noradrenaline, tyramine and dopamine but measurements were inconsistent because sometimes the levels were below the limits of detection. Metabolites of a number of biogenic amines were readily detected in aqueous and vitreous humour.

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.

Penile scarring with intracavernous injection therapy using prostaglandin E1: a risk factor analysis.

PURPOSE: We attempted to identify risk factors for penile scarring in patients using prostaglandin E1 injection therapy. MATERIALS AND METHODS: Records of 92 patients using prostaglandin E1 therapeutically were reviewed. With statistical methods, patients with (15) and without (77) scarring were compared. RESULTS: No significant differences between the 2 groups were found regarding duration of followup, injection frequency, prostaglandin E1 dose per injection, total number of injections or total prostaglandin E1 dose. Patients with initial penile scarring did not have a significantly higher incidence of further scarring with prostaglandin E1. CONCLUSIONS: Penile scarring with prostaglandin E1 injection therapy is sporadic and unpredictable. Patients with initial penile scarring do not have a higher incidence of further scarring.