Nicholas J. Hegarty

Correlation of Radiographic Imaging and Histopathology Following Cryoablation and Radio Frequency Ablation for Renal Tumors

PURPOSEnFollowup after radio frequency ablation and cryotherapy for small renal lesions lacks pathological analysis. The definition of successful tumor ablation has been the absence of contrast enhancement on posttreatment magnetic resonance imaging or computerized tomography. We hypothesized that adding post-ablation kidney biopsy would help confirm treatment success.nnnMATERIALS AND METHODSnFrom April 2002 to March 2006 a total of 109 renal lesions in 88 patients were ablated with percutaneous radio frequency ablation and from September 1997 to January 2006 a total of 192 lesions in 176 patients were treated with laparoscopic cryoablation. Patients were followed with radiographic imaging and post-ablation biopsy at 6 months.nnnRESULTSnRadiographic success at 6 months was 85% (62 cases) and 90% (125) for radio frequency ablation and cryoablation, respectively. At 6 months 134 lesions (45%) were biopsied and success in the radio frequency ablation cohort decreased to 64.8% (24 cases), while cryoablation success remained high at 93.8% (91). Six of 13 patients (46.2%) with a 6-month positive biopsy after radio frequency ablation demonstrated no enhancement on posttreatment magnetic resonance imaging or computerized tomography. In patients treated with cryoablation all positive biopsies revealed posttreatment enhancement on imaging just before biopsy.nnnCONCLUSIONSnWe observed a poor correlation between radiographic imaging and pathological analysis. We recommend post-radio frequency ablation followup biopsy due to the significant risk of residual renal cell cancer without radiographic evidence, although to our knowledge the clinical significance of these viable cells remains to be determined. In contrast, radiographic images of renal lesions treated with cryotherapy appeared to correlate adequately with corresponding histopathological findings in our series.

Surgical Salvage of Renal Cell Carcinoma Recurrence After Thermal Ablative Therapy

PURPOSEnThermal ablative therapies, including cryoablation and radio frequency ablation, have become viable options for the management of small renal tumors. However, initial data have suggested higher local recurrence rates for ablation compared to partial nephrectomy. We evaluated options for salvage of ipsilateral tumor recurrence after previous ablation.nnnMATERIALS AND METHODSnRecords of renal surgeries performed at our institution between September 1997 and December 2006 were reviewed to identify patients with ipsilateral tumor recurrence after radio frequency ablation or cryoablation, and clinical characteristics and treatment were defined.nnnRESULTSnRecurrence rates at our hospital were 13 of 175 (7.4%) after cryoablation and 26 of 104 (25%) after radio frequency ablation, and 3 additional cases of post-cryoablation recurrence were referred from elsewhere. Overall repeat ablation was performed in 26 patients who experienced post-ablative recurrence. However, 12 patients (33%) were not candidates for repeat ablation due to large tumor size, disease progression or repeat ablative failure. In this group 1 patient received systemic therapy, 1 refused further treatment and 10 underwent attempted extirpation. Partial nephrectomy was only possible in 2 patients and both required an open approach. Remaining patients were treated with radical nephrectomy (7) or had the procedure aborted due to strong patient preference to avoid dialysis (1). Laparoscopic surgery was only possible in 4 cases. Extensive perinephric scarring was encountered in all salvage operations following cryoablation.nnnCONCLUSIONSnPrimary thermal ablation for small renal masses may preclude or complicate subsequent surgical salvage. Cryoablation in particular can lead to extensive perinephric fibrosis which can complicate attempts at salvage. Appropriate patient selection for thermal ablation remains of paramount importance.

Functional Outcomes Following Percutaneous Surgery in the Solitary Kidney

PURPOSEnWe assessed the impact of percutaneous renal surgery on renal function based on the modification of diet in renal disease estimated glomerular filtration rate in solitary renal units. We also determined the variables predictive of functional improvement or impairment following percutaneous surgery in solitary kidneys.nnnMATERIALS AND METHODSnA prospective database was augmented by retrospective chart review. Between 1984 and 2007, 81 patients with a solitary kidney, which was anatomical in 61.7%, functional in 18.5%, a transplant allograft in 11.1% and unknown in 8.6%, underwent a total of 92 percutaneous procedures. Serum creatinine was measured preoperatively, postoperatively, at 1 month and at 1 year. The 4-variable modification of diet in renal disease equation was used to calculate estimated creatinine clearance. The study population was divided into 3 groups, including group 1-a change in the estimated glomerular filtration rate of 5% or less at 1 year, group 2-an increase of greater than 5% at 1 year and group 3-a decrease of greater than 5% at 1 year. Univariate and multivariate regression analysis was performed using the ordinal logistic fit model to assess the effects of variables on postoperative renal function at 1 year.nnnRESULTSnPercutaneous intervention was performed for stone disease in 64 patients (69.6%), of whom 25 had staghorn calculi. Two patients required concomitant antegrade endopyelotomy for ureteropelvic junction obstruction. Percutaneous resection of transitional cell carcinoma was performed in 28 patients (30.4%). Of the patients 46% had baseline stage 3 chronic kidney disease. Complications developed in 8 patients (8.6%). In the entire cohort the modification of diet in renal disease estimated glomerular filtration rate was 44.7, 42.5, 55.4 and 49.9 ml per minute per 1.73 m(2) at baseline, immediately postoperatively, at 1 month and at 1 year, respectively. Female gender (OR 3.11, p = 0.0038) and an initial postoperative improvement in modification of diet in renal disease estimated glomerular filtration rate of greater than 5% (OR 6.84, p = 0.0026) were predictive of renal function improvement at 1 year on multivariate analysis.nnnCONCLUSIONSnPercutaneous renal surgery in the solitary kidney is safe and it results in renal function preservation for up to 1 year of followup. Female gender and an immediate postoperative improvement in the modification of diet in renal disease estimated glomerular filtration rate are predictive of a sustained increase in that rate at 1 year.

Is retroperitoneal approach feasible for robotic dismembered pyeloplasty: initial experience and long-term results.

OBJECTIVESnTo present our initial series of robotic-assisted retroperitoneal dismembered pyeloplasty in adults patients using the da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA).nnnMETHODSnTen adult patients with unilateral ureteropelvic junction (UPJ) obstruction underwent robotic-assisted retroperitoneoscopic Anderson-Hynes dismembered pyeloplasty between February 2004 and March 2005. UPJ obstruction was primary in six patients and secondary in four patients after failed endopyelotomy. Dismembered pyeloplasty was performed utilizing a retroperitoneal approach (developed by balloon dissection). Three retroperitoneal laparoscopic ports were placed for the robot, and a fourth port was used by the assistant. Robotic-assisted laparoscopic technique was utilized to perform the entire procedure in all cases.nnnRESULTSnAll cases (seven right, three left) were successfully completed using the robot without conversion to conventional laparoscopic or open technique. Median surgical time was 175 minutes (95% confidence interval [CI] 128-185), median estimated blood loss was 50 mL (95% CI, 26-62), and the median hospital stay was 48 hours (95% CI, 27-65). No complications occurred. At a mean follow-up of 30 months (range 24-36), clinical symptomatic assessment with a numeric pain scale, health-related quality of life evaluation with the Short Form 36 health survey, and functional assessment with Tc-99m-mercaptoacetyltriglycine, diuretic renography, and intravenous urogram demonstrated a successful outcome in all cases.nnnCONCLUSIONSnRobotic-assisted dismembered pyeloplasty can be performed efficiently by the retroperitoneal laparoscopic technique. Our surgical outcomes are comparable to previously published laparoscopic and transperitoneal robotic-assisted dismembered pyeloplasty series in adults with excellent clinical and radiologic success rates.

Ureteroscopic versus Percutaneous Treatment for Medium-Size (1–2-cm) Renal Calculi

PURPOSEnTo compare the outcomes of percutaneous nephrolithotomy (PCNL) and ureterorenoscopy (URS) for 1- to 2-cm renal calculi with specific reference to the stone clearance rate and morbidity.nnnPATIENTS AND METHODSnThe records of 27 patients who underwent either PCNL (N = 15) or URS (N = 12) by standard techniques over an 8-month period for renal calculi between 1 and 2 cm were reviewed retrospectively. Demographic, intraoperative, and postoperative data were accrued and compared to identify any statistically significant differences. The median stone burden was slightly but not significantly higher in the PCNL group (1.8 cm v 1.25 cm; P = 0.19). Postoperative plain films were used to confirm stone clearance.nnnRESULTSnThe procedure was technically successful in all 27 patients. No patient in either group required a repeat session or ancillary procedure. All 15 PCNL procedures were completed through a single percutaneous tract. The PCNL and URS groups were equivalent with respect to operative time (79.0 minutes v 68.5 minutes) and incidence of complications (2 v 0). No patient in either group had significant hemorrhage or required blood transfusion. The overall stone-free rate was 87% for PCNL and 67% for URS (P = 0.36).nnnCONCLUSIONSnBoth PCNL and URS are effective options for renal calculi between 1 and 2 cm. The stonefree and complication rates for PCNL are higher, but the differences were not statistically significant in our series. The operative times are statistically equivalent, despite the potentially longer fragmentation times required for URS. The choice of treatment ultimately depends on the individual surgeons preference and level of expertise.

Minimally invasive nephron‐sparing surgery for renal cell cancer

factors. Examples include renal calculus disease, chronic pyelonephritis, diabetes mellitus, and Von Hippel–Lindau disease. Elective indications include a small ( ≤ 4 cm) renal tumour in the presence of a normal opposite kidney. Short-term disadvantages of open NSS include the morbidity of the open incision, greater blood loss, urine leak and potential for re-exploration (Table 1) [4,6–9], whilst in the long term there is a small risk of ipsilateral disease recurrence. Decisive factors in the elective setting include surgeon experience, size and position of tumour, comorbidity, and patient preference.

Robotic Urologic Surgery: An Introduction and Vision for the Future

Robots have been defined as “a reprogrammable, multifunctional manipulator designed to move materials, parts, tools, or specialized devices through various programmed motions for the performance of a variety of tasks” by the Robot Institute of America. Websters’ English dictionary describes robots as “an automatic apparatus or device that performs functions normally ascribed to humans or operates with what appears to be almost human intelligence.” These definitions encompass three levels of functionality—the ability to perform defined maneuvers, the ability to perform such tasks in a preprogrammed order, and the ability to interpret and modify responses to commands, based on experience and learning.

Laparoscopic Partial Nephrectomy for Tumour in the Presence of Nephrolithiasis or Pelvi-Ureteric Junction Obstruction.

To report on patients with a small renal mass and concomitant calculus or pelvi‐ureteric junction obstruction (PUJO), and to propose an algorithm for minimally invasive management when these conditions coexist, as the success of laparoscopic partial nephrectomy (LPN) depends greatly on the absence after surgery of ureteric obstruction.