2119
ORIGINAL RESEARCH—SURGERY Three-Year Outcomes of Recovery of Erectile Function after Open Radical Prostatectomy with Sural Nerve Grafting Khurram M. Siddiqui, FRCS,*† Michelle Billia, MD,* Clarisse R. Mazzola, MD,* Ali Alzahrani, MD,*‡ Gerald B. Brock, FRCSC,* Christopher Scilley, FRCSC,* and Joseph L. Chin, FRCSC* *Department of Surgery, University of Western Ontario, London, Ontario, Canada; †Department of Surgery, The Aga Khan University, Karachi, Pakistan; ‡Department of Surgery, Dammam University, Dammam, Saudi Arabia DOI: 10.1111/jsm.12600
ABSTRACT
Introduction. Optimal oncologic control of higher stage prostate cancers often requires sacrificing the neurovascular bundles (NVB) with subsequent postoperative erectile dysfunction (ED), which can be treated with interposition graft using sural nerve. Aims. To examine the long term outcome of sural nerve grafting (SNG) during radical retropubic prostatectomy (RRP) performed by a single surgeon. Methods. Sixty-six patients with clinically localized prostate cancer and preoperative International Index of Erectile Function (IIEF) score >20 who underwent RRP were included. NVB excision was performed if the risk of side-specific extra-capsular extension (ECE) was >25% on Ohori’ nomogram. SNG was harvested by a plastic surgeon, contemporaneously as the urologic surgeon was performing RRP. IIEF questionnaire was used pre- and postoperatively and at follow-up. Main Outcome Measures. Postoperative IIEF score at three years of men undergoing RRP with SNG. Recovery of potency was defined as postoperative IIEF-EF domain score >22. Results. There were 43 (65%) unilateral SNG and 23 (35%) bilateral SNG. Mean surgical time was 164 minutes (71 to 221 minutes).The mean preoperative IIEF score was 23.4 + 1.6. With a mean follow-up of 35 months, 19 (28.8%) patients had IIEF score >22. The IIEF-EF scores for those who had unilateral SNG and bilateral SNG were 12.9 + 4.9 and 14.8 + 5.3 respectively. History of diabetes (P = 0.001) and age (P = 0.007) negatively correlated with recovery of EF. 60% patients used PDE5i and showed a significantly higher EF recovery (43% vs. 17%, P = 0.009). Conclusions. SNG can potentially improve EF recovery for potent men with higher stage prostate cancer undergoing RP. The contemporaneous, multidisciplinary approach provides a good quality graft and expedited the procedure without interrupting the work-flow. Siddiqui KM, Billia M, Mazzola CR, Alzahrani A, Brock GB, Scilley C, and Chin JL. Three-year outcomes of recovery of erectile function after open radical prostatectomy with sural nerve grafting. J Sex Med 2014;11:2119–2124. Key Words. Prostate Cancer; Radical Prostatectomy; Sural Nerve Grafting; Errectile Dysfunction; Erectile Function Recovery
Introduction
O
ptimal oncologic control of higher—stage prostate cancers may require wider resection of peri-prostatic tissue thereby sacrificing the neurovascular bundles (NVB) at the time of radical prostatectomy, with subsequent postoperative erectile dysfunction (ED). As erectile function
© 2014 International Society for Sexual Medicine
recovery is associated with higher quality-of-life and improved overall well-being, there have been numerous attempts in the past to improve erectile function recovery after surgery in those patients in whom NVB preservation was not advisable. Conflicting data have been reported to date regarding sural nerve grafting (SNG). However, variations in the surgical technique and in the definition of ED, J Sex Med 2014;11:2119–2124
2120 as well as inadequate follow-up were limitations in previously published series.
Aim
To assess the 3-year outcomes of recovery of erectile function after standardized SNG performed by a single surgeon at an academic health sciences center.
Methods
This prospective study was conducted at our center from 2002 to 2010. Ethical approval was obtained by the institutional ethics review board and 66 patients with clinically localized prostate cancer (c2Tb+) and IIEF >20 were included. Preoperative data, including all co-morbid conditions linked with erectile dysfunction (smoking, presence of hypercholerstolemia, diabetes, neurogenic causes, hypertension etc.) were recorded. All patients were staged with computerized tomography and/or magnetic resonance imaging and radio-nucleotide bone scan to exclude metastatic disease. Patients were excluded from the study in presence of an International Index of Erectile Function (IIEF) score 25% underwent ipsilateral NVB resection and reconstruction as per Ohori’s nomogram [2]. However, the final decision of NVB resection was made based on intraoperatively findings. The sural nerve graft (SNG) was harvested by a plastic surgeon (CS) using a standard surgical technique in all patients while the Urologic surgeon continued with the prostate dissection contemporaneously, without interrupting the work-flow [3]. The mean length of SNG for unilateral grafting was 6.5 cm and 12 cm for bilateral grafting. All the RP and nerve grafting were performed by the urologic oncology surgeon (JLC) who interposed the nerve between the cut ends of the NVB (which had been tagged during the periprostatic dissection). The anastomosis was performed under 2.5X magnification using 7-0 polypropylene monofilament suture. The polarity of the nerve was reversed during grafting. If excess nerve length was available, a “double cable” graft was performed. The urethro-vesical anastomosis was completed after SNG. J Sex Med 2014;11:2119–2124
Siddiqui et al. Main Outcome Measures
All patients completed the standard IIEF selfassessment questionnaire before the surgery and at follow-up visits [4]. Recovery of potency was defined in our study as a postoperative IIEF-EF domain score >22. All patients were encouraged to use phosphodiesterase type 5 inhibitors (PDE5i), but no specific protocol of penile rehabilitation was used. Statistical analysis was performed using the R software (Language and Environment for Statistical Computing). For comparison among treatment groups with respect to the availability covariates, the T, x2, and Fisher’s tests were used. Two sided P values were considered statistically significant if they were 22). Seven (10.6%) patients had IIEF of 18–21, 28 (42.4%) patients scored 11–17 and 12 (18.1%) patients reported IIEF 1–10. The IIEF-EF scores were 12.9 ± 4.9 and 14.8 ± 5.3 among patients who received uni- and bilateral SNG, respectively. Patients over 60 years of age had significantly lower EF recovery compared to younger patients (35% vs. 65%).
2121
Recovery of Erectile Function after Radical Prostatectomy Using Sural Nerve Graft Table 1
Preoperative clinical and pathological characteristics of the sural nerve graft (SNG) patients All patients (N = 66) N(%) or mean (SD)
Characteristics Age (year) ≤60 ≥60 BMI (kg/m2) ≤25 25–30 >30 Pre-op PSA ng/nl Prostate volume Clinical stage T2b T3a % Tumor involvement ≤20 20–40 40–60 >60 Gleason score ≤6 7 >8 Preoperative IIEF score 1–10 (Severe ED) 11–17 (Moderate ED) 18–21 ( Mild–moderate ED) 22–25 (Mild ED) >26 (No ED)
USNG (N = 43) N(%) or mean (SD)
BSNG (N = 23) N(%) or mean (SD)
P value
34 (51) 32 (49)
19 (44) 24 (56)
8 (35) 15 (55)
0.165
40 (61) 15 (22) 11 (17) 7.19 (3.84) 37.87 (9.9)
27 (63) 10 (23) 6 (14) 7.42 (3.94) 39.18 (11.18)
13 (56) 5 (22) 5 (22) 7.03 (3.65) 35.04 (6.33)
0.415
59 (89) 7 (11)
38 (88) 5 (12)
21 (91) 2 (9)
0.885
2 (4) 20 (30) 20 (30) 24 (24)
2 (5) 12 (28) 14 (32) 15 (15)
— 4 (17) 9 (39) 10 (44)
0.976
20 (30) 33 (50) 13 (20)
20 (46) 21 (49) 2 (5)
6 (26) 13 (56) 4 (18)
0.847
— — — 60 (100) —
— — — 43 (100) —
— — — 23 (100) —
0.988 0.249
0.185
IIEF = International Inventory of Erectile Function; BMI = body mass index; UNSG = unilateral sural nerve graft; BSNG = bilateral sural nerve graft
Table 2 shows the functional outcomes in patients treated with unilateral and bilateral SNG. Although we recommended on-demand PDE5i to all the patients, only 40 patients (60%) reported its use. Of note, we observed a significantly higher EF recovery in the subgroup of patients treated with PDE5i (43% vs. 17%, P = 0.009). The oncologic outcomes are reported in Table 3. In our series, 12 patients developed biochemical recurrence after a mean follow-up of 35 months. Adjuvant radiation was given to 14 patients, 11 of them received on demand PDE5i and 5 were able to have adequate erection (IIEF > 22). Table 2 Functional outcomes in unilateral and bilateral sural nerve graft
Characteristics PDE5-i therapy Yes No Incontinence Severe Mild–moderate Continent
USNG (N = 43) N(%) or mean (SD)
BSNG (N = 23) N(%) or mean (SD)
25 (58) 18 (42)
15 (65) 8 (35)
— 3 (7) 40 (93)
1 (4) 2 (9) 20 (87)
PDE5-i = phosphodiesterase type 5 inhibitor
P value 0.7669
—
History of diabetes (P = 0.001) and age (P = 0.007) negatively correlated with recovery of EF. Our results did not show that the type of SNG was a significant predictor for recovery (Table 4).
Table 3 Oncologic outcome in bilateral sural nerve grafting patients Characteristics Gleason score ≤6 7 >8 Unknown Pathologic stage pT2c pT3a pT3b Tumor involvement, mean (range) Surgical margin (%) Positive Negative Location of PSM (%) Apex Postero-lateral Bladder neck All above
USNG (N = 43)
BSNG (N = 23)
10 19 8 6
7 13 1 2
28 8 7 35 (15–60)
7 13 3 24 (18–30)
8 35
2 21
—
1 3 2 2
— — 1 1
—
P value
0.23
0.769
0.432
J Sex Med 2014;11:2119–2124
2122 Table 4
Siddiqui et al. Univariable and multivariable linear regression model predicting erectile function
Variable intercept Nerve graft Bilat vs. Unilat Diabetes (Y or N) Age (60) IIEF (22 vs. >22) Hospital stay BMI (>25 vs. 250 cases per year) the weighted mean operative time for RRP was found to be 165 minutes [9]. Our operative time for RRP including SNG was within the range for a typical RRP. One limitation of the existing literature for SNG is the lack of adequate follow-up and inconsistent definition of EF recovery [10]. The process of graft-assisted regeneration is not only dependent on the quality of graft, but also on the time required for graft aided regeneration, which typically extends to a year [11]. Hence, optimal nerve graft quality, techniques and adequate follow-up are critical for reliable assessment of the utility of SNG. In this study 3-year follow-up is presented using, the validated and widely used IIEF questionnaire
Recovery of Erectile Function after Radical Prostatectomy Using Sural Nerve Graft [12]. Recovery of erectile function was defined as a postoperative IIEF-EF score of >22, a definition proposed by Briganti et al. [13]. Although an IIEF score of 26 was originally considered normal, Briganti et al. compared the patient satisfaction with the erectile function after bilateral nerve preserving radical prostatectomy and found no difference in patient satisfaction with IIEF score ≥22 and 26. An obvious criticism of our results is the fact that those with unilateral SNG could attribute their IIEF-EF score to the contralateral un-resected but ungrafted NVB, and not to the SNG. Our results showed no difference in IIEF scores between those with unilateral and bilateral SNG. With the increased operative efficiency we feel that 28.8% overall rate of preservation of potency with no statistical difference between the unilateral and bilateral SNG (P = 0.84) justifies consideration in a select patient population, especially i.e., younger (60 years show return to baseline erectile function after RP [14]. Therefore we recommend that in younger patients the addition of SNG is especially worthwhile in cases of bilateral nerve resection as the chances of spontaneous recovery are remote. Secein et al. reported 34% 5-year erectile function preservation after bilateral NVB reconstruction which is similar to our results. This study used a five-point rigidity scale self-administered by the surgeon [15]. In another study by Chang et al., a very high success rate of 72% is reported [16]. However, they used Rigiscan findings to report the outcome and did not use a standardized questionnaire to assess the EF. The overwhelming trend in radical prostatectomy surgery is that the laparoscopic robotassisted approach has become much more prevalent than the open approach in certain parts of the world. SNG during robotic prostatectomy has been reported in some smaller series [15], with sequential prostate dissection and nerve harvesting. The interpositioning graft procedure is certainly suited for the robotic approach, given optical magnification and fine motor movements are optimized with the surgical robotic. However, contemporaneous nerve harvesting during robotic prostatic dissection described by our group would be logistically more challenging although not impossible. Limitations of our study on this prospective cohort include the nonrandomized nature and lack
2123
of a control group, as well as the residual erectile function from the preserved NVB. Conclusions
Sural nerve grafting is one of the options for preservation of EF for potent men undergoing RP for high volume prostate cancer. A multidisciplinary contemporaneous approach provides a good quality graft with minimal added morbidity and negligible added surgical complexity appears to render SNG justifiable in selected patients where unilateral or bilateral wide excision of the NVB(s) is warranted and where there is a strong desire to preserve erectile function. Corresponding Author: Joseph L. Chin, FRCSC, Department of Surgery, University of Western Ontario, 800 Commissioner Rd E, London, ON N6A 5W9, Canada. Tel: 5196858451; Fax: 5196858455; E-mail: [email protected] Conflict of Interest: The authors report no conflicts of interest.
Statement of Authorship
Category 1 (a) Conception and Design Joseph L. Chin; Christopher Scilley (b) Acquisition of Data Khurram M. Siddiqui; Michelle Billia (c) Analysis and Interpretation of Data Khurram M. Siddiqui; Michelle Billia
Category 2 (a) Drafting the Article Khurram M. Siddiqui; Clarisse R. Mazzola (b) Revising It for Intellectual Content Gerald Brock; Joseph L. Chin
Category 3 (a) Final Approval of the Completed Article Joseph L. Chin
References 1 Stember DS, Nelson CJ, Mulhall JP. Preoperative erectile function is an independent predictor for decision to spare cavernous nerves during radical prostatectomy. J Sex Med 2013;10:2101–7. 2 Ohori M, Kattan MW, Koh H, Maru N, Slawin KM, Shariat S, Muramoto M, Reuter VE, Wheeler TM, Scardino PT. Predicting the presence and side of extracapsular extension: A nomogram for staging prostate cancer. J Urol 2004;171: 1844–9.
J Sex Med 2014;11:2119–2124
2124 3 Sunderland S. Nerve grafting and related methods of nerve repair. In: Sunderland S ed. Nerve injuries and their repair: A critical appraisal. New York: Churchill Livingston; 1991: 449–67. 4 Rosen RC, Cappelleri JC, Gendrano N 3rd. The International Index of Erectile Function (IIEF): A state-of-the-science review. Int J Impot Res 2002;14:226–44. 5 Kundu SD, Roehl KA, Eggener SE, Antenor JA, Han M, Catalona WJ. Potency, continence and complications in 3,477 consecutive radical retropubic prostatectomies. J Urol 2004; 172:2227–31. 6 Mulhall JP, Bivalacqua TJ, Becher EF. Standard operating procedure for the preservation of erectile function outcomes after radical prostatectomy. J Sex Med 2013;10:195–203. 7 Kim ED, Scardino PT, Hampel O, Mills NL, Wheeler TM, Nath RK. Interposition of sural nerve restores function of cavernous nerves resected during radical prostatectomy. J Urol 1999;161:188–92. 8 Davis JW, Chang DW, Chevray P, Wanga R, Shen Y, Wenc S, Pettaway CA, Pisters LL, Swanson DA, Madsen LT, Huber N, Troncoso P, Babaian RJ, Wood CG. Randomized phase II trial evaluation of erectile function after attempted unilateral cavernous nerve-sparing retropubic radical prostatectomy with versus without unilateral sural nerve grafting for clinically localized prostate cancer. Eur Urol 2009;55: 1135–44. 9 Coelho RF, Rocco B, Patel MB, Orvieto MA, Chauhan S, Ficarra V, Melegari S, Palmer KJ, Patel VR. Retropubic, laparoscopic, and robot-assisted radical prostatectomy: A critical
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11 12
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16
review of outcomes reported by high-volume centers. J Endourol 2010;24:2003–15. White WM, Kim ED. Interposition nerve grafting during radical prostatectomy: Cumulative review and critical appraisal of literature. Urology 2009;74:245–50. Slawin KM, Canto EI, Shariat SF. Sural nerve interposition grafting during radical prostatectomy. Rev Urol 2002;4:17–23. Rosen RC, Riley A, Wagner G, Osterloh IH, Kirkpatrick J, Mishra A. The international index of erectile function (IIEF): A multidimensional scale for assessment of erectile dysfunction. Urology 1997;49:822–30. Briganti A, Gallina A, Suardi N, Capitanio U, Tutolo M, Bianchi M, Salonia A, Colombo R, Di Girolamo V, Martinez-Salamanca JI, Guazzoni G, Rigatti P, Montorsi F. What is the definition of a satisfactory erectile function after bilateral nerve sparing radical prostatectomy? J Sex Med 2011; 8:1210–7. Nelson CJ, Scardino PT, Eastham JA, Mulhall JP. Back to baseline: Erectile function recovery after radical prostatectomy from the patients’ perspective. J Sex Med 2013;10:1636–43. Secin FP, Koppie TM, Scardino PT, Eastham JA, Patel M, Bianco FJ, Tal R, Mulhall J, Disa JJ, Cordeiro PG, Rabbani F. Bilateral cavernous nerve interposition grafting during radical retropubic prostatectomy: Memorial Sloan-Kettering Cancer Center experience. J Urol 2007;177:664–8. Chang DW, Wood CG, Kroll SS, Youssef AA, Babaian RJ. Cavernous nerve reconstruction to preserve erectile function following non-nerve-sparing radical retropubic prostatectomy: A prospective study. Plast Reconstr Surg 2003;111:1174–81.
ORIGINAL RESEARCH—SURGERY Three-Year Outcomes of Recovery of Erectile Function after Open Radical Prostatectomy with Sural Nerve Grafting Khurram M. Siddiqui, FRCS,*† Michelle Billia, MD,* Clarisse R. Mazzola, MD,* Ali Alzahrani, MD,*‡ Gerald B. Brock, FRCSC,* Christopher Scilley, FRCSC,* and Joseph L. Chin, FRCSC* *Department of Surgery, University of Western Ontario, London, Ontario, Canada; †Department of Surgery, The Aga Khan University, Karachi, Pakistan; ‡Department of Surgery, Dammam University, Dammam, Saudi Arabia DOI: 10.1111/jsm.12600
ABSTRACT
Introduction. Optimal oncologic control of higher stage prostate cancers often requires sacrificing the neurovascular bundles (NVB) with subsequent postoperative erectile dysfunction (ED), which can be treated with interposition graft using sural nerve. Aims. To examine the long term outcome of sural nerve grafting (SNG) during radical retropubic prostatectomy (RRP) performed by a single surgeon. Methods. Sixty-six patients with clinically localized prostate cancer and preoperative International Index of Erectile Function (IIEF) score >20 who underwent RRP were included. NVB excision was performed if the risk of side-specific extra-capsular extension (ECE) was >25% on Ohori’ nomogram. SNG was harvested by a plastic surgeon, contemporaneously as the urologic surgeon was performing RRP. IIEF questionnaire was used pre- and postoperatively and at follow-up. Main Outcome Measures. Postoperative IIEF score at three years of men undergoing RRP with SNG. Recovery of potency was defined as postoperative IIEF-EF domain score >22. Results. There were 43 (65%) unilateral SNG and 23 (35%) bilateral SNG. Mean surgical time was 164 minutes (71 to 221 minutes).The mean preoperative IIEF score was 23.4 + 1.6. With a mean follow-up of 35 months, 19 (28.8%) patients had IIEF score >22. The IIEF-EF scores for those who had unilateral SNG and bilateral SNG were 12.9 + 4.9 and 14.8 + 5.3 respectively. History of diabetes (P = 0.001) and age (P = 0.007) negatively correlated with recovery of EF. 60% patients used PDE5i and showed a significantly higher EF recovery (43% vs. 17%, P = 0.009). Conclusions. SNG can potentially improve EF recovery for potent men with higher stage prostate cancer undergoing RP. The contemporaneous, multidisciplinary approach provides a good quality graft and expedited the procedure without interrupting the work-flow. Siddiqui KM, Billia M, Mazzola CR, Alzahrani A, Brock GB, Scilley C, and Chin JL. Three-year outcomes of recovery of erectile function after open radical prostatectomy with sural nerve grafting. J Sex Med 2014;11:2119–2124. Key Words. Prostate Cancer; Radical Prostatectomy; Sural Nerve Grafting; Errectile Dysfunction; Erectile Function Recovery
Introduction
O
ptimal oncologic control of higher—stage prostate cancers may require wider resection of peri-prostatic tissue thereby sacrificing the neurovascular bundles (NVB) at the time of radical prostatectomy, with subsequent postoperative erectile dysfunction (ED). As erectile function
© 2014 International Society for Sexual Medicine
recovery is associated with higher quality-of-life and improved overall well-being, there have been numerous attempts in the past to improve erectile function recovery after surgery in those patients in whom NVB preservation was not advisable. Conflicting data have been reported to date regarding sural nerve grafting (SNG). However, variations in the surgical technique and in the definition of ED, J Sex Med 2014;11:2119–2124
2120 as well as inadequate follow-up were limitations in previously published series.
Aim
To assess the 3-year outcomes of recovery of erectile function after standardized SNG performed by a single surgeon at an academic health sciences center.
Methods
This prospective study was conducted at our center from 2002 to 2010. Ethical approval was obtained by the institutional ethics review board and 66 patients with clinically localized prostate cancer (c2Tb+) and IIEF >20 were included. Preoperative data, including all co-morbid conditions linked with erectile dysfunction (smoking, presence of hypercholerstolemia, diabetes, neurogenic causes, hypertension etc.) were recorded. All patients were staged with computerized tomography and/or magnetic resonance imaging and radio-nucleotide bone scan to exclude metastatic disease. Patients were excluded from the study in presence of an International Index of Erectile Function (IIEF) score 25% underwent ipsilateral NVB resection and reconstruction as per Ohori’s nomogram [2]. However, the final decision of NVB resection was made based on intraoperatively findings. The sural nerve graft (SNG) was harvested by a plastic surgeon (CS) using a standard surgical technique in all patients while the Urologic surgeon continued with the prostate dissection contemporaneously, without interrupting the work-flow [3]. The mean length of SNG for unilateral grafting was 6.5 cm and 12 cm for bilateral grafting. All the RP and nerve grafting were performed by the urologic oncology surgeon (JLC) who interposed the nerve between the cut ends of the NVB (which had been tagged during the periprostatic dissection). The anastomosis was performed under 2.5X magnification using 7-0 polypropylene monofilament suture. The polarity of the nerve was reversed during grafting. If excess nerve length was available, a “double cable” graft was performed. The urethro-vesical anastomosis was completed after SNG. J Sex Med 2014;11:2119–2124
Siddiqui et al. Main Outcome Measures
All patients completed the standard IIEF selfassessment questionnaire before the surgery and at follow-up visits [4]. Recovery of potency was defined in our study as a postoperative IIEF-EF domain score >22. All patients were encouraged to use phosphodiesterase type 5 inhibitors (PDE5i), but no specific protocol of penile rehabilitation was used. Statistical analysis was performed using the R software (Language and Environment for Statistical Computing). For comparison among treatment groups with respect to the availability covariates, the T, x2, and Fisher’s tests were used. Two sided P values were considered statistically significant if they were 22). Seven (10.6%) patients had IIEF of 18–21, 28 (42.4%) patients scored 11–17 and 12 (18.1%) patients reported IIEF 1–10. The IIEF-EF scores were 12.9 ± 4.9 and 14.8 ± 5.3 among patients who received uni- and bilateral SNG, respectively. Patients over 60 years of age had significantly lower EF recovery compared to younger patients (35% vs. 65%).
2121
Recovery of Erectile Function after Radical Prostatectomy Using Sural Nerve Graft Table 1
Preoperative clinical and pathological characteristics of the sural nerve graft (SNG) patients All patients (N = 66) N(%) or mean (SD)
Characteristics Age (year) ≤60 ≥60 BMI (kg/m2) ≤25 25–30 >30 Pre-op PSA ng/nl Prostate volume Clinical stage T2b T3a % Tumor involvement ≤20 20–40 40–60 >60 Gleason score ≤6 7 >8 Preoperative IIEF score 1–10 (Severe ED) 11–17 (Moderate ED) 18–21 ( Mild–moderate ED) 22–25 (Mild ED) >26 (No ED)
USNG (N = 43) N(%) or mean (SD)
BSNG (N = 23) N(%) or mean (SD)
P value
34 (51) 32 (49)
19 (44) 24 (56)
8 (35) 15 (55)
0.165
40 (61) 15 (22) 11 (17) 7.19 (3.84) 37.87 (9.9)
27 (63) 10 (23) 6 (14) 7.42 (3.94) 39.18 (11.18)
13 (56) 5 (22) 5 (22) 7.03 (3.65) 35.04 (6.33)
0.415
59 (89) 7 (11)
38 (88) 5 (12)
21 (91) 2 (9)
0.885
2 (4) 20 (30) 20 (30) 24 (24)
2 (5) 12 (28) 14 (32) 15 (15)
— 4 (17) 9 (39) 10 (44)
0.976
20 (30) 33 (50) 13 (20)
20 (46) 21 (49) 2 (5)
6 (26) 13 (56) 4 (18)
0.847
— — — 60 (100) —
— — — 43 (100) —
— — — 23 (100) —
0.988 0.249
0.185
IIEF = International Inventory of Erectile Function; BMI = body mass index; UNSG = unilateral sural nerve graft; BSNG = bilateral sural nerve graft
Table 2 shows the functional outcomes in patients treated with unilateral and bilateral SNG. Although we recommended on-demand PDE5i to all the patients, only 40 patients (60%) reported its use. Of note, we observed a significantly higher EF recovery in the subgroup of patients treated with PDE5i (43% vs. 17%, P = 0.009). The oncologic outcomes are reported in Table 3. In our series, 12 patients developed biochemical recurrence after a mean follow-up of 35 months. Adjuvant radiation was given to 14 patients, 11 of them received on demand PDE5i and 5 were able to have adequate erection (IIEF > 22). Table 2 Functional outcomes in unilateral and bilateral sural nerve graft
Characteristics PDE5-i therapy Yes No Incontinence Severe Mild–moderate Continent
USNG (N = 43) N(%) or mean (SD)
BSNG (N = 23) N(%) or mean (SD)
25 (58) 18 (42)
15 (65) 8 (35)
— 3 (7) 40 (93)
1 (4) 2 (9) 20 (87)
PDE5-i = phosphodiesterase type 5 inhibitor
P value 0.7669
—
History of diabetes (P = 0.001) and age (P = 0.007) negatively correlated with recovery of EF. Our results did not show that the type of SNG was a significant predictor for recovery (Table 4).
Table 3 Oncologic outcome in bilateral sural nerve grafting patients Characteristics Gleason score ≤6 7 >8 Unknown Pathologic stage pT2c pT3a pT3b Tumor involvement, mean (range) Surgical margin (%) Positive Negative Location of PSM (%) Apex Postero-lateral Bladder neck All above
USNG (N = 43)
BSNG (N = 23)
10 19 8 6
7 13 1 2
28 8 7 35 (15–60)
7 13 3 24 (18–30)
8 35
2 21
—
1 3 2 2
— — 1 1
—
P value
0.23
0.769
0.432
J Sex Med 2014;11:2119–2124
2122 Table 4
Siddiqui et al. Univariable and multivariable linear regression model predicting erectile function
Variable intercept Nerve graft Bilat vs. Unilat Diabetes (Y or N) Age (60) IIEF (22 vs. >22) Hospital stay BMI (>25 vs. 250 cases per year) the weighted mean operative time for RRP was found to be 165 minutes [9]. Our operative time for RRP including SNG was within the range for a typical RRP. One limitation of the existing literature for SNG is the lack of adequate follow-up and inconsistent definition of EF recovery [10]. The process of graft-assisted regeneration is not only dependent on the quality of graft, but also on the time required for graft aided regeneration, which typically extends to a year [11]. Hence, optimal nerve graft quality, techniques and adequate follow-up are critical for reliable assessment of the utility of SNG. In this study 3-year follow-up is presented using, the validated and widely used IIEF questionnaire
Recovery of Erectile Function after Radical Prostatectomy Using Sural Nerve Graft [12]. Recovery of erectile function was defined as a postoperative IIEF-EF score of >22, a definition proposed by Briganti et al. [13]. Although an IIEF score of 26 was originally considered normal, Briganti et al. compared the patient satisfaction with the erectile function after bilateral nerve preserving radical prostatectomy and found no difference in patient satisfaction with IIEF score ≥22 and 26. An obvious criticism of our results is the fact that those with unilateral SNG could attribute their IIEF-EF score to the contralateral un-resected but ungrafted NVB, and not to the SNG. Our results showed no difference in IIEF scores between those with unilateral and bilateral SNG. With the increased operative efficiency we feel that 28.8% overall rate of preservation of potency with no statistical difference between the unilateral and bilateral SNG (P = 0.84) justifies consideration in a select patient population, especially i.e., younger (60 years show return to baseline erectile function after RP [14]. Therefore we recommend that in younger patients the addition of SNG is especially worthwhile in cases of bilateral nerve resection as the chances of spontaneous recovery are remote. Secein et al. reported 34% 5-year erectile function preservation after bilateral NVB reconstruction which is similar to our results. This study used a five-point rigidity scale self-administered by the surgeon [15]. In another study by Chang et al., a very high success rate of 72% is reported [16]. However, they used Rigiscan findings to report the outcome and did not use a standardized questionnaire to assess the EF. The overwhelming trend in radical prostatectomy surgery is that the laparoscopic robotassisted approach has become much more prevalent than the open approach in certain parts of the world. SNG during robotic prostatectomy has been reported in some smaller series [15], with sequential prostate dissection and nerve harvesting. The interpositioning graft procedure is certainly suited for the robotic approach, given optical magnification and fine motor movements are optimized with the surgical robotic. However, contemporaneous nerve harvesting during robotic prostatic dissection described by our group would be logistically more challenging although not impossible. Limitations of our study on this prospective cohort include the nonrandomized nature and lack
2123
of a control group, as well as the residual erectile function from the preserved NVB. Conclusions
Sural nerve grafting is one of the options for preservation of EF for potent men undergoing RP for high volume prostate cancer. A multidisciplinary contemporaneous approach provides a good quality graft with minimal added morbidity and negligible added surgical complexity appears to render SNG justifiable in selected patients where unilateral or bilateral wide excision of the NVB(s) is warranted and where there is a strong desire to preserve erectile function. Corresponding Author: Joseph L. Chin, FRCSC, Department of Surgery, University of Western Ontario, 800 Commissioner Rd E, London, ON N6A 5W9, Canada. Tel: 5196858451; Fax: 5196858455; E-mail: [email protected] Conflict of Interest: The authors report no conflicts of interest.
Statement of Authorship
Category 1 (a) Conception and Design Joseph L. Chin; Christopher Scilley (b) Acquisition of Data Khurram M. Siddiqui; Michelle Billia (c) Analysis and Interpretation of Data Khurram M. Siddiqui; Michelle Billia
Category 2 (a) Drafting the Article Khurram M. Siddiqui; Clarisse R. Mazzola (b) Revising It for Intellectual Content Gerald Brock; Joseph L. Chin
Category 3 (a) Final Approval of the Completed Article Joseph L. Chin
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