PD16-12 HIGH POWERED MICROWAVE ABLATION OF T1A RENAL CANCER: PRELIMINARY SAFETY AND CLINICAL EFFICACY

THE JOURNAL OF UROLOGYâ

Vol. 191, No. 4S, Supplement, Sunday, May 18, 2014

CONCLUSIONS: Robotic partial nephrectomy was associated with more than 70% preservation of function in the operated kidney and 80% of the total eGFR in our series. Amount of normal renal parenchymal removal at the time of tumor resection, is an independent factor in predicting the percentage of eGFR preservation in the affected kidney.

comparability, but these results were obtained in selected cases and by high volume robotic surgeons. Future studies will need to validate these results. Comparison of peri-operative outcomes of RPN and OPN for simple (RNS 4-8) & complex renal masses (RNS 9-12)

Factors predicting %GFR preservation in the operated kidney

Tumor Volume(cc) Pre-op eGFR RENAL Score WIT > 20 min Renal parenchyma removed(per 10cc)

Effect Size 0.08 -0.20 -0.72 -11.3 -1.05

95.0% Confidence Interval for effect size (-0.05,0.22) (-0.39,-0.008) (-3.4,1.98) (-23.08,0.48) (-2.09,-0.003)

p 0.21 0.042 0.60 0.06 0.049

WIT:warm ischemic time; eGFR estimated glomerular function rate

Source of Funding: none

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Complexity groups

RPN

Simple RNS

Complex

(4-8)

RNS (9-12)

OPN

No.

30

33

Pathological largest tumor

2.5

3.5

R.E.N.A.L Score (median)

6

No. of tumors per

1

Operative Time (mean, min) Est. Blood Loss (median, ml)

p

RPN

p

OPN

10

55

n.s

4

4.4

n.s

7

n.s

9.5

10

n.s

1

n.s

1

1

n.s

174.961.7

185.4256.4

n.s

250.866

245.358.6

n.s

200

300

n.s

225

300

n.s

21,70

18,54.7

0.03

10,100

26,47.3

n.s

15

23

22.75.8

23.97.9

Size (median,cm)

kidney(median)

Ischemic Time (min) Warm N, % Median/Mean Cold

PD16-11 COMPARISON OF PERI-OPERATIVE OUTCOMES OF ROBOTIC PARTIAL NEPHRECTOMY AND OPEN PARTIAL NEPHRECTOMY IN IN PATIENTS WITH SOLITARY KIDNEYS Homayoun Zargar*, Cleveland, OH; Jeffrey Larson, St. Louis, MO; Mark. W. Ball, Baltimore, MD; Susan Marshall, New york, NY; Ramesh Kumar, Detroit, MI; Sam. B. Bhayani, St. Louis, MO; M. E. Allaf, Baltimore, MD; Michael. D. Stifelman, New york, NY; Craig G. Rogers, Detroit, MI; Amr Fergany, Steven c. Campbell, Jihad H. Kaouk, Cleveland, OH INTRODUCTION AND OBJECTIVES: There is paucity of data in the literature regarding comparison of robotic partial nephrectomy (RPN) with open partial nephrectomy (OPN) in solitary kidneys.We aim to compare the perioperative outcomes of RPN with OPN in this setting. METHODS: We retrospectively reviewed records of consecutive cases of RPN performed in 5 high volume centres across USA from 2007 to mid 2013. We limited our study to PN in solitary kidneys. We compared these cases with patients with tumor(s) in solitary kidneys who underwent OPN during the same period. To control for variation in tumor complexity across the two treatment arms, cases were divided into simple (4-8) and complex (9-12) groups according to R.E.N.A.L nephrometry score (RNS). Demographics, surgical, pathological and follow-up data were compared between OPN and LPN in each group. RESULTS: Total of 128 patients (40 RPN and 88 OPN) were identified for the comparison. There was no difference between the treatment modalities in terms of age, sex, body mass index or Charlson comorbidity index. There were higher proportions of OPN cases in the complex RNS group (62.5% vs. 25%; p<0.001). Within the simple group, there was no difference between the two surgical approaches in terms of overall intra-operative and postoperative complications, transfusion rate, and positive surgical margin rates. Within the complex group, there was no difference between the two surgical approaches in terms of overall intra-operative and postoperative complications, transfusion rate, WIT and positive surgical margin rates. For both simple and complex groups the patients in the RPN group had a shorter length of hospital stay (3 vs. 5; p<0.001 for simple group, 4 vs. 6; p¼0.001 for complex group). For the entire cohort, there was no difference between the two approaches in percentage of eGFR preservation beyond 1 month (OPN 79.6%, RPN 80.6%). CONCLUSIONS: In the setting of PN in a solitary kidney, RPN offers comparable perioperative and short-term functional outcomes for localized renal masses with low RNS when compared to OPN. For more complex tumors, our early experience suggests

N, %

1,3.3

7,21.2

Mean

8

42.3312.8

8,26.7

8,24.2

1(3.3%)

0

No Ischemia N,% Intra-operative

—

27,49.1

—

—

46.918.4

—

n.s

0

2(3.6%)

—

n.s

1(10%)

4(7.2%)

n.s

n.s

Complications 0

0

—

0

2(3.6%)

n.s

Injury to other structures

1(3.3%)

0

n.s

1(10%)

2(3.6%)

n.s

Transfusion

6(20%)

5(15.2%)

n.s

0

8(14.5%)

0

Post-operative

9(30%)

16(48.5%)

n.s

4(40%)

23(41.8%)

n.s

1

3(10%)

6(18.2%)

0

10(18.2%)

2

3(10%)

3(9.1%)

0

4(7.3%)

3a

1(3.3%)

1(3%)

0

1(1.8%)

3b

1(3.3%)

2(6.1%)

1(10%)

3(5.5%)

4a

1(3.3%)

4(12.1%)

3(30%)

5(9.1%)

3

5

Kidney loss

Complications Clavien Score

Hospital Stay(median,days)

n.s

<0.001

4

Positive Margin(%)

2(8%)

2(6%)

n.s

1(10%)

Follow up time

12.6

14

n.s

14.3

4

n.s

0.001

4(8%) 18.8

n.s n.s

(mean, months)

Source of Funding: None

PD16-12 HIGH POWERED MICROWAVE ABLATION OF T1A RENAL CANCER: PRELIMINARY SAFETY AND CLINICAL EFFICACY Sara Best*, Anna Moreland, Timothy Ziemlewicz, J. Louis Hinshaw, Meghan Lubner, Marci Alexander, Christopher Brace, Douglas Kitchin, Sean Hedican, Stephen Nakada, Fred Lee, E. Jason Abel, Madison, WI INTRODUCTION AND OBJECTIVES: Percutaneous radiofrequency (RF) and cryoablation are accepted alternative treatments for small renal cell carcinomas (RCC) in high-risk surgical candidates. However, local tumor recurrence remains a persistent concern and the ability to treat larger tumors is limited. High powered microwave (MW) ablation offers several theoretical advantages over RF including higher tissue temperatures, more reproducible ablation zones, no grounding pads, and shorter procedural times. The high powered MW antenna has a gas cooled mechanism to enable high tissue temperatures without the antenna shaft overheating seen in prior instruments. In this study we report the largest series of percutaneous MW T1a RCC ablations to date and review the feasibility, safety, and early efficacy. METHODS: After obtaining Institutional Review Board approval, an institutional database of ablation patients was queried. 42 patients with biopsy-proven T1a RCC (43 tumors) were identified who

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Vol. 191, No. 4S, Supplement, Monday, May 19, 2014

had been undergone percutaneous MW ablation using a novel highpowered, gas-cooled system. Post-procedure follow-up imaging was performed by contrast-enhanced CT or MRI. RESULTS: Mean patient age was 67 years and 79% of patients were male. RCC subtypes included clear cell (n¼29), papillary (n¼10), and unspecified (n¼4) with Fuhrman grades 1 (n¼12), 2 (n¼19), and ungraded (n¼11). Mean tumor diameter was 2.6 cm. Mean ablation time was 6.0 minutes at 67 watts. Median follow-up was 6 months. No residual tumor was observed on immediate post-procedure CT or follow-up CT or MRI for any tumor, conferring a technical effectiveness and local tumor control of 100%. Complications (two Clavien Grade 1 (urine retention and rash), one Grade 2 (hemorrhage requiring transfusion) occurred in 3/ 43 (6.9%) of procedures. No patients have evidence of local recurrence or metastasis. Post procedure eGFR was not significantly changed from pre-procedure levels (mean: -2.3 mL/min/ 1.73m2, p>0.05). CONCLUSIONS: Use of a high-powered microwave ablation system for the treatment of T1a renal cell carcinoma is feasible, safe, and efficacious at short-term follow-up. Further studies and continued follow up are warranted to demonstrate long-term oncologic outcomes. Source of Funding: none

Plenary Session II: Best Abstracts Monday, May 19, 2014

7:30 AM-7:58 AM

PII-01 ROUTINE IMAGING FOLLOWING PERCUTANEOUS NEPHROLITHOTOMY: SHOULD WE BE SCREENING FOR SILENT OBSTRUCTION? Lawrence Dagrosa*, Rachel Moses, Vernon Pais Jr., Lebanon, NH INTRODUCTION AND OBJECTIVES: Obstruction is a potentially serious complication following upper tract instrumentation. As such, routine renal imaging following ureteroscopy has been recommended to screen for post-operative asymptomatic “silent” hydronephrosis. We could find no published data however on the rates of silent hydronephrosis following percutaneous nephrolithotripsy (PCNL). We assessed the incidence of silent hydronephrosis in a single endourologic practice following both Ureteroscopy and PCNL. METHODS: Using billing data, 488 patients were identified as having ureteral stent removal by a single surgeon from 2008 to 2013 after undergoing ureteroscopy or PCNL for urinary calculi. Routine follow-up imaging reports were reviewed and the degree of hydronephrosis noted (none, mild, moderate or severe.) Patients found to have ultrasonic evidence of hydronephrosis that was new or worse compared to pre-op imaging were further analyzed for resolution of hydro, time to resolution and need for intervention. RESULTS: Of the 488 patients identified 16 (3.3%) were found to have new or worsened hydronephrosis on routine follow-up ultrasound. In the ureteroscopy group 9 of 367 (2.4%) had evidence of hydro, 5 resolved spontaneously, 2 had functional imaging negative for obstruction and 2 had obstruction requiring intervention (endoureterotomy). In the PCNL group 7 of 121 patients (5.7%) had evidence of hydronephrosis at routine follow-up, 5 resolved spontaneously, 1 has stable mild hydro and declined functional imaging and 1 was lost to follow-up. Mean time to spontaneous resolution

was 10 mo. ( 9.2) and 15 mo. ( 16) in the Ureteroscopy and PCNL groups respectively. CONCLUSIONS: Our data showing a 2.4% rate of hydronephrosis following ureteroscopy is consistent with previously reported data (0 - 4.8% in 7 published series). We now add to the literature an assessment of the rate of silent hydronephrosis following PCNL of 5.7%, which is similar to that rate observed after ureteroscopy suggesting routine imaging following PCNL to screen for silent obstruction is warranted. Source of Funding: None

PII-02 UNINTENDED NEGATIVE CONSEQUENCES OF PRIMARY ENDOSCOPIC REALIGNMENT FOR MEN WITH PELVIC FRACTURE URETHRAL INJURIES J. Francis Scott, Timothy J. Tausch*, Jay Simhan, Allen F. Morey, Dallas, TX INTRODUCTION AND OBJECTIVES: Controversy continues regarding whether patients with pelvic fracture urethral injuries (PFUI) are best treated by either early primary endoscopic realignment (PER) or suprapubic diversion with delayed urethroplasty. We evaluated the histories of patients referred to our institution following PFUI in an attempt to elucidate the clinical course of care associated with these two management strategies. METHODS: We retrospectively reviewed our IRB-approved, prospectively collected urethroplasty database from 2007-2013. Patients with a PFUI etiology were stratified into two groups based on initial urethral injury treatment: Group 1 received suprapubic diversion and definitive urethroplasty, while Group 2 underwent initial PER. We recorded the number of endoscopic interventions and time from injury to successful definitive treatment. Data regarding stricture length, reconstruction technique, and treatment outcomes were analyzed. Successful surgery was defined as having no identifiable stricture on voiding cystourethrogram. RESULTS: Among 748 urethroplasty cases performed during the study interval, 37 (5%) PFUI cases were identified with complete information available, and all underwent repair by excision with primary anastomosis. For Group 1 patients (21/37, 57%), the median time to resolution of stenosis was dramatically shorter (6 mo, range 3-15) compared with primary realignment cases [(16/37 (43%); 25 mo (4-574); p < 0.01)]. One-fourth of Group 2 patients (4/16, 25%) endured a treatment course that spanned more than two decades preceding urethroplasty. All Group 2 patients required endoscopic urethral interventions (median 4, range 1-36) prior to presenting for definitive reconstruction, while only one patient required any interval procedure in Group 1 (p < 0.01). While all 21 patients in Group 1 had resolution of obstructive voiding symptoms after urethroplasty, only 13 (81%, p ¼ 0.09) PER patients had successful posterior urethroplasty. Two Group 2 failures eventually had successful reoperative urethroplasties and another required an additional buccal mucosa graft procedure for a synchronous stricture. There was no difference in stricture length between Groups 1 and 2 (mean 2.6 vs. 2.8 cm, p ¼ 0.70). CONCLUSIONS: Treatment of pelvic fracture urethral disruption injuries by primary realignment appears to be associated with unintended negative consequences including multiple additional interventions, less reliable urethroplasty, and a prolonged clinical course delaying durable treatment of obstructive voiding symptoms. Source of Funding: NONE