Versatility of 3D laproscopy for radical prostatectomy: A single tertiary cancer center experience

Abstract

Objective

The objective of this study is to compare our institutional outcomes of 3D laparoscopic when compared with open radical prostatectomy in terms of functional and oncological outcomes.

Methods

This is a retrospective study of patients who underwent radical prostatectomy during the period January 2016 to September 2019 at our institute. Out of 49 patients who underwent radical prostatectomy, 23 were done by open approach and 25 were operated by 3D laparoscopy. One patient was lost to follow-up and was excluded from the study. Data were collected from medical records, and functional evaluation was done by telephonic interview. Data analysis was done by SPSS software to calculate overall and disease-free survival.

Results

Laparoscopic arm patients had lesser blood loss, postoperative pain, hospital stay and wound-related issues although they had a longer operating time. Functional outcomes in terms of erectile dysfunction and incontinence were almost similar in both open and 3D laparoscopic approach. No statistically significant difference was observed for overall survival or disease-free survival. All shortcomings with the laparoscopic arm were improved as our experience increased with 3D laparoscopic prostatectomy. The outcomes of 3D laparoscopic radical prostatectomy were comparable to previously published data of robotic radical prostatectomy.

Conclusions

3D LRP is a feasible technique with similar oncological or functional outcomes and better perioperative outcomes as compared to ORP. Being cost-effective and with comparable outcomes it is a suitable alternative to RRP in resource-limited settings.

INTRODUCTION

Radical prostatectomy has been considered as one of the treatment options for low, intermediate and selected high-risk non-metastatic cases of carcinoma of the prostate. Various approaches for radical prostatectomy are described, including open and minimally invasive techniques like conventional laparoscopy, 3D (3-dimensional) laparoscopy and robotics. Traditionally, open prostatectomy was considered the gold standard approach. With the advent of laparoscopic radical prostatectomy (LRP) in the early 1990s, various evidences showed a reduction in blood loss, transfusion rates, postoperative pain, length of hospital stay and duration of catheterization but similar oncological and functional outcomes [1–5]. Major disadvantages attributed to laparoscopy are constrained 2-dimensional (2D) visualization of pelvic anatomy and prolonged learning curve, which has hindered its application worldwide. Robotic radical prostatectomy (RRP) was introduced in 2003 to overcome the technical challenges of conventional LRP and thus has taken over as the dominant approach because of a better 3-dimensional view of pelvic anatomy and better ergonomics with an increased degree of movements and dexterity. Although RRP has been widely accepted in the western world, it has not been popular in developing countries because of the cost and limited availability. Moreover, no oncological or functional superiority has been proven till date. 3D laparoscopy provides a better 3-dimensional visualization of anatomy as in robotics, which to an extent helps in overcoming the drawbacks of 2D laparoscopy and open surgery.

Ours is a tertiary cancer center, and since the facility for robot is yet to be available, we performed radical prostatectomy via open or 3D laparoscopic approach depending on patient factors. Since the acquaintance of 3D laparoscopy, we have not preferred 2D systems for radical prostatectomy because of ease of its use and better depth perception. Additionally, a lot of literature comparing 2D and 3D is available, but there is paucity of data comparing 3D with open. So, a head-to-head comparison with 2D laparoscopy was not feasible. Best modality for RP in terms of postoperative complication, functional and oncological outcomes is still debated even after the advent of minimally invasive approaches like robotics and laparoscopy [6]. Most of recently published data showed a need of high-quality RCT to prove advantage of robotics over open approaches [6] which may not be feasible because of its inherent advantages and better ergonomics in pelvic surgeries, especially RP. So we aimed to compare our institutional outcomes of 3D laparoscopic with open radical prostatectomy which was once considered gold standard approach and still not proven inferior to other approaches. We also intend to find out whether it can be a feasible alternative to RRP, especially in resource limiting settings by comparing our outcomes with major published data for RRP.

Methodology

Study design and population

A retrospective analysis of all the patients of carcinoma of the prostate who underwent radical prostatectomy between January 2016 and September 2019 at our institute was done. Both open and laparoscopic surgeries were performed by a single-trained uro-onco surgeon.

Outcome measurements and statistical analysis

Patients with non-metastatic localized prostate cancer deemed fit for surgery after multidisciplinary board discussions were included in the study. Preoperative parameters like age, serum prostate-specific antigen (PSA), preoperative 12 core TRUS biopsy with Gleason score and D’Amico risk groups were noted for both the procedures.

Open radical prostatectomy were performed by the standard technique as described by Walsh et al. [7]. 3D LRP was performed by the technique as described by Guillonneau et al. [8]. Nerve sparing was performed whenever possible and indicated. Urethra was divided at the apex to make sure that maximal urethral length was available for anastomosis at the same time not compromising oncological safety. Bladder neck was repaired in fish mouth pattern in all cases before anastomosis. Perioperative outcomes in the form of total operative time, blood loss, postoperative pain with analgesic requirement, time to ambulation and hospital stay were retrieved for both the procedures. Final histopathological parameters were also noted. Follow-up details assessing functional outcomes like continence and erectile dysfunction were documented.

All the data were collected from prospectively maintained medical records. Telephonic interviews were used to gather missing data. Patients lost to follow-up were excluded from the study. Analysis of the data was done by IBM SPSS Statistics for Windows, Version 25.0.

Results

Demographic characteristics

A total of 49 patients underwent radical prostatectomy from January 2016 to September 2019, out of which 25 were operated by 3D laparoscopy and 24 underwent open radical prostatectomy (ORP). One patient who underwent ORP was lost to follow-up and so was excluded from the study. Demographic characteristics (Table 1) showed that the mean age of the patients was 66 years (46–80 years). For 3D LRP, it was 67 years and for ORP, it was 65 years. Mean preoperative serum PSA was 18 ng/ml (1.2 – 92 ng/dl). The mean serum PSA was almost similar in the ORP arm as compared to the 3D LRP arm (16.5 ng/ml vs 16 ng/ml). Risk stratification was done as per D’Amico scoring system. Distribution of cases between both arms as low, intermediate and high risks was comparable. The majority of the patients operated were from intermediate risk groups (65%).

Table 1.

Results of Demography, Tumor characteristics

	TOTAL(48)	3D LRP(N = 25)	Open RP(N = 23)
Age (Mean in years)	66.59 (46–80)	67.9 (52–80)	65 (46–78)
Serum PSA(ng/ml)	18.1(1.2–92)	16(1.2–55)	16.5(8.8–92)
Gleason's Score
6	19	10	09
7	19	10	09
8	08	04	04
9	02	01	01
D’Amico Scoring
Low risk	07	04	03
Intermediate	31	16	15
High Risk	10	05	05
TUMOR CHARACTERSTICS
Tumor Volume (% of prostate involved)	60%(10–95%)	55%(10–90%)	66%(10–95%)
Extracapsular extension
Nil	21	12	9
Present	27	13	14
Seminal Vesicle Involvement
Yes	21	13	8
No	27	12	15
Nodal Metastasis
Yes	20	10	10
No	28	15	13
No: Nodes dissected	549	256	293
No: Positive nodes	51	23	28
Average Nodal Yield	11.43	10.24	12.73
Margin Status
Negative	35	16	19
Positive	13(27%)	7(28%)	6(26%)
Number Of positive Margins
1	9	4	5
2	3	2	1
3 or more	1	1	0
Adjuvant Treatment
Yes	9	6	3
No	39	19	20
Death	5	3	2
Postoperative	1	1	0
Disease related	2	1	1
Not related to tumor	2	1	1

Perioperative outcomes and Complications

Perioperative events (Table 5) had significant changes in the latter half of 3D laparoscopic surgery as the experience of the surgeon increased. Mean intraoperative duration was 175 min. When compared to ORP, 3D LRP had a higher operating time (180 min vs. 160 min). Mean blood loss was around 225 ml, with 3D LRP patients having less blood loss as compared to ORP (150 ml vs. 280 ml). When comparing the initial half cases of 3D LRP with its later half, operating time reduced from 200 to 160 min and blood loss reduced from 220 ml to140ml (Table 5). Thus as the experience of our team increased, the outcomes of laparoscopic surgery improved. About 80% of patients who underwent 3D LRP were able to ambulate on the first post-op day itself, whereas in ORP arm only 35% of patients were able to do so. Oral and intravenous analgesic requirement was significantly lower in patients who underwent 3D LRP (requirement for 3 days compared to 7 days). Average hospital stay was significantly less for 3D LRP (4 in lap vs. 7 days in open). As a protocol Foley's removal was done on the 7th day for patients in both the arms.

Table 5.

Urinary continence and potency recovery in the comparative studies between RRP and ORP

Study	Cases, n	Continence Definition	Potency definition	Data Collection	Urinary continence at 12 months, n/N(%)	Potency recovery at 12 months, n/N (%)
Coughlin et al [22]	RARP 163 ORP 163	No pad	IIEF-5	Questionnaire	131/146(89.7) 123/135(91.1)	74/146(50.7) 65/135(48.1)
Haglind et al [19]	RARP 1,847 ORP 778	No pad	-	Questionnaire	1207/1745(69.2) 480/720(66.7)	-
Sooriakumaran et al [23]	RARP 1,792 ORP 753	-	Stiff enough	Questionnaire	-	128/1792(7.1) 62/753(8.2)
Ong et al [13]	RARP 885 ORP 1,117	No/very small urinary bother	No/very small sexual bother	Interview/ Questionnaire	466/639(72.9) 513/731	167/639(26.1) 200/731
Our study	3D LRP 25 ORP 23	No pad soakage	IIEF-5	Interview	22/25(88) 20/23(87)	3/25(12%) 3/23(13%)

There was no significant difference in morbidity and mortality between the two arms. Morbidity grading was done by the Clavien-Dindo classification. Significant morbidity (grades 3 and 4) was present in only 6 patients (12%), 3 patients each in 3D LRP and ORP. Re-exploration was required in 2 patients; one patient who underwent 3D LRP had rectal injury detected postoperatively and was re-explored for repair of rectal injury and diverting colostomy was done. One patient who underwent ORP had a burst abdomen, which needed re-suturing. Other major morbidities were hematuria, pneumonia, wound-related issues and electrolyte imbalances. There was single 30-day mortality out of 24 (4.16%) patients who underwent 3D LRP due to cardiac cause, whereas no mortality was noted in patients who underwent ORP.

Pathological Outcomes

The postoperative pathological evaluation showed the following tumor characteristics (Table 1). Most of the patients had Gleason's score of 6 or 7. Extracapsular extension was seen in about 27 out of 48 (56%) of patients (13 out of 25 (52%) in 3D LRP and 14 out of 23 (60%) in ORP). Seminal vesicle involvement was seen in 21 out of 48 (40%) of patients (13 out of 25 (52%) in 3D LRP and 8 out of 23 (23%) in ORP).

Nodal assessment showed that the nodal yield was better in ORP patients as compared to 3D LRP (12.7 vs. 10.24 nodes). Nodal yield improved in patients who underwent surgery in the latter half of the 3D LRP subset (12 vs. 9.2 nodes).

Overall there was an incidence of 27% margin positivity (13 out of 48 patients) (Table 1). The positivity rate was slightly higher in the 3D LRP arm (28%) when compared to the ORP arm (26%); the difference was not statistically significant. Among margin positive cases majority (70%, 9/13) were single margin positive and the most common margin to be positive was the apex of prostate (70%) followed by base and lateral margin.

Functional Outcomes

Differences in functional outcomes in both arms were not statistically significant (Table 2). Postprocedure erectile dysfunction assessed by the International Index of Erectile Function (IIEF -5) showed an overall incidence of 18 out of 48 patients (37.5%), and incontinence (questionnaire based on soakage of pads and patients complaints) was seen in 9 out of 48 (18.7%). Recovery of incontinence was seen in most patients. Persistence of the same after 1 year was seen in around 12% cases in both arms. Erectile dysfunction rate was seen in 9 out of 25 (36%) in the 3D LRP arm and 9 out of 23 (39.1%) in the ORP arm. Incontinence was seen in 4 out of 23 cases in ORP arm (17.3%) as compared to 5 out of 25 (20%) in 3D LRP arm. However, better functional results were seen in patients operated in the latter half of the 3D LRP arm. The postoperative stricture was seen in 4 patients totally (2 each in each arm).

Table 2.

Perioperative, functional and oncological outcomes

	TOTAL(48)	3D LRP(N = 25)	Open RP(N = 23)	Difference Significance(p)
PERIOPERATIVE EVENTS
Intraop Duration(min)	175(140–260)	180(140–260)	160(140–200)
Blood loss(ml)	225(100–800)	150(100–700)	280(100–800)
Analgesic requirement
IV analgesia(days)	3	2	3
Oral analgesia(days)	6	5	7	0.125
Hospital Stay(days)	6(3–26)	4(3–16)	7(5–26)	0.718
Ambulation(days)
1st day	28	20(80%)	8(35%)
2nd day	17	4	13
3rd day	1	0	1
4 or more	2	1	1
Catheter Removal(days)	7	7	7	0.034
Morbidity	3	2	1
Grade 3	3	1	2
Grade 4
Mortality(30 day)	1	1	0
Unilateral Nerve Sparing	5	3	2
Bilateral Nerve Sparing	4	3	1
FUNCTIONAL OUTCOMES
Erectile Dysfunction ( IIEF -5)	18	9(36%)	9(39%)	0.709
ED at 12 months	12(25%)	6(24%)	6(26%)
Incontinence at 3 months	9	5(20%)	4(17%)	0.817
Incontinence at 1 year	6	3(12%)	3(13%)
ED at 1 year after NS	2/9(22%)	1/6(17%)	1/3(33%)
Local Recurrence	2	1(4%)	1 (4.3%)	0.907
Distal Recurrence	6	4(16%)	2(8.6%)	0.130
Mean overall survival (Months)		41	42	0.292
Disease-free survival (Months)		36	40	0.272

Unilateral nerve sparing (NS) was attempted in two patients in ORP and three patients in 3D LRP. Bilateral nerve sparing was attempted in 3 patients in 3D LRP and one patient in ORP. Nerve sparing was better feasible in 3D LRP arm patients. Out of 9 patients who underwent NS (6 in 3D LRP and 3 in ORP) 2 had ED. Our rate for it was almost similar for entire subset (22 vs 25%). But 3D LRP patients had better erectile function when NS was attempted among the patients who underwent 3D LRP (17% vs 36% had ED at one year). The results should be interpreted with a caution owing to the paucity of the cases undergoing NS surgery.

Oncological Outcomes

Disease recurrence

Disease recurrence (Table 1) was defined as development of new lesion after surgery and was classified as local and distant. Overall 8 patients (17%) had disease recurrence out of which 2 had local recurrence (1 each in each arm) and 6 had distant metastasis mainly in the form of bone metastasis. Distant metastasis was seen in 4 patients in the laparoscopic arm and 2 patients in the open arm. Patients with distant metastasis had adverse preoperative factors like high serum PSA and Gleason’s score. Five out of 6 patients had pelvic node positivity for the disease.

Overall survival

Overall survival (OS) was defined as the time from diagnosis to death due to any cause. Three-year OS was 81.5% and 80.3% in ORP and 3D LRP arms, respectively. The mean OS was 42 months and 41 months (Table 1) in ORP and 3D LRP arms, respectively. This difference in survival was not statistically significant (p = 0.292) (Fig. 1). Cox regression analysis showed that out of variables assessed for overall survival like age, Gleason’s score, post-TURP status, serum PSA, extracapsular spread, node positivity, margin positivity, LVI and PNI only serum PSA was statistically significant as per our study.

Fig. 1.

Kaplan–Meier curve (OS)

Disease-free Survival

Disease-free survival (DFS) was defined as the time from diagnosis to date of recurrence. Three-year DFS was 84% and 78% in ORP and 3D LRP arms, respectively. Mean DFS was 40 months and 36 months in ORP and 3D LRP arms, respectively. This difference was not statistically significant (p = 0.272).

Discussion

Minimally invasive surgery (laparoscopic and robotics) has gained popularity as the preferred treatment modality for various surgeries. Radical prostatectomy is a procedure in which robotic surgery has obtained a significant momentum in western countries because of its ease of use in space-constrained pelvic cavity and its inherent advantages like binocular 3D vision, 10 times magnification, tremor filtration, motion scaling and seven degrees of surgical freedom. In developing countries, its availability is limited due to the cost. This has led many investigators to search for a modality that had advantages of robotics with limited cost [8, 9].

Unfortunately, classic LRP is limited by a 2D vision that does not allow depth perception of the operative field as in ORP. For this reason, there is increasing popularity of 3D laparoscopy systems [10] in which the tissue handling becomes meticulous and precise, especially the dissection of delicate structures. This higher accuracy might translate to better functional and oncological outcomes.

A comparison of oncological outcomes between two arms in our series showed no statistically significant difference in overall survival or disease-free survival. Positive margin status was slightly higher in LRP (28% vs. 26%). Published data showed varying results in major studies, with some having higher rates in minimally invasive techniques while some having higher rates in ORP [11, 12]. Our results showed that functional outcomes in terms of erectile dysfunction and incontinence were almost similar in both arms. No statistically significant difference was observed in survival. Even though operating time was longer, laparoscopic surgeries had lesser blood loss, postoperative pain, hospital stay and wound issues. Our results were encouraging for 3D LRP, and when compared with published data for RRP results were at par with those. There are data regarding the learning curve of LRP for low-volume surgeons. Significantly less intraoperative complications were evident after the first 51 cases, and other parameters (blood loss, operative time and positive surgical margins) significantly decreased after 110 cases [13]. Multi-institutional studies have shown the learning curve to be 200–250 cases [14]. Other evidence has shown that 3D LRP is similar to any other new surgical procedure and as with open surgery we learn and gain experience with each procedure, but the learning curve is never completely finished [15]. As our experience in 3D LRP increased, we compared our results of the initial half with the latter half of 3D LRP. We observed a decline in its shortcomings, and a trend of improvement in surgical and functional outcomes has been shown (Table 3). Further better outcomes are contemplated as learning curve is surpassed.

Table 3.

Comparison of two phases of 3D LRP

3D Laproscopy	Initial half (n = 13)	Latter half (n = 12)
Operating time(min)	200	160
Blood loss(ml)	220	140
Margin Positivity(n)	5	2
Erectile Dysfunction(n)	7	3
Incontinence(n)	3	2

Though from our study head-to-head comparison of 3D LRP with RRP is not possible, our results were compared with previously published major data for RRP and ORP (Table 4 and 5); the results were comparable to ORP as well as RRP. Mean operative time in major studies [16–18] for RRP was 180–300 min, LRP was 180–220 min, and ORN was 120–180 min. In our analysis, it was 180 min for 3D lap and 160 min for ORP. The operative time was higher initially as compared to ORP which may be a part of the learning curve for the 3D LRP procedure. However, with experience it decreased and was similar to the ORP procedure. Mean blood loss was significantly higher in ORP (500-1000 ml) when compared to LRP (200-300 ml) and RRP (180-250 ml) [12, 17, 18]. In our study it was less for 3D LRP (150 ml) as compared to ORP (280 ml) and may be attributed to better visualization of DVC and therefore its better control in 3D LRP. Also, magnified 3D vision might have helped in better hemostasis throughout the surgery. Postoperative pain and hospital stay were less when operated by minimal invasive techniques. LRP and RRP patients were discharged on 2–4 days and LRP on 4–7 day [, and 17–19]. We routinely discharge patients on 5-7th days as per our routine policy. Morbidity (12.5%) and mortality (2%) rates were comparable with most of the studies. Decreased postoperative pain was seen in 3D LRP cases because of the decreased size of the incision, and subsequently, there was a decreased analgesic requirement. Other complications were similar in both procedures; however, one patient had a rectal injury in the 3D LRP arm that had SV involvement and extensive fibrosis postbiopsy even after 4 weeks. The mortality in the 3D LRP arm was due to cardiac cause unrelated to disease. Seminal vesicle involvement was higher in the 3D LRP arm; however, all cases had complete removal of the seminal vesicles and most of them showed extracapsular extension in the final HPE with negative margins.

Table 4.

Perioperative characteristics and postoperative complications in the comparative studies between RARP/LRP and ORP

Author	Cases, n	Operative time(Min) Mean/Median	Blood loss,ml Mean/Median	Hospital stay Mean/Median(days)	Overall complications(%)
Yaxley et al [20]	RARP157 ORP 151	222.03 ± 51.63 234.34 ± 37.07	443.74 ± 294.29 1,338.14 ± 591.47	1.55 ± 2.61 3.27 ± 1.49	7 (4.5) 16 (10.6)
Guazzoni et al [21]	LRP 60 ORP 60	235 ± 49.8 170 ± 34.2	257.3 ± 177 853.3 ± 485	–	–
Wallerstedt et al [18]	RARP1847 ORP 778	175 (45–575) 103 (40–428)	185 (0–5200) 683 (50–8,000)	3.3 (2–53) 4.1 (1–17)	–
Forsmark et al [17]	RARP 1835 ORP 803	172.4 ± 48.8 101.5 ± 44.3	_	2.4 ± 1.8 3.1 ± 1.7	–
Jurczok et al [12]	LRP 163 ORP 240	180 (120–240) 120 (80–190)	200 (100–700) 550 (200–1,900)	9.4 11.2	15 (9.2) 25 (10.4)
Our Study	3D LRP 25 ORP 23	180 (140–260) 160 (140–200)	150 (100–700) 280 (100–800)	6 (4–16) 7 (5–26)	3 (6) 3 (6)

Functional evaluation assessed in terms of urinary continence and erectile dysfunction was also comparable to other studies as shown in Table 5. Erectile dysfunction was seen in around 37%, almost similar rates seen in ORP and LRP. The incidence of persistent incontinence was seen in 10% of patients with similar occurrences in both ORP and LRP. The reported incidence of impotence was varying from 10 to 50% [13, 22, 23]with almost similar rates in all ORP, LRP and RRP when done in the same center. Similar observations were seen in the occurrence of urinary incontinence with an incidence of around 10–20% [13, 19, 22]. In our study we noted an improvement in functional outcomes in the 3D LRP arm in the later half when we gained experience in laparoscopy.

The advantage of our study is that comparison of 3D LRP with ORP has been done for the first time as per our knowledge. Secondly the findings of our study prove the utility of 3D LRP as an alternative to RRP in resource limiting settings.

The main limitation of our study is that it is a retrospective study. There is a comparison of minimal invasive technique with an open technique. The experience of the surgeon may have influenced the results and complications rates of our study due to initial learning phase with the 3D system, and as a result, the outcomes cannot be generalized. Lastly, the sample size was small with relatively short follow-up. Some data may not be statistically significant between groups because the study was not powered to identify these differences. But we intent to publish our interim results since our results were encouraging with a cost-effective 3D LRP. However, a prospective, multi-institutional study comparing all the three approaches with long-term follow-up data will throw more light on the ever burning debate regarding best approach for performing radical prostatectomy.

Conclusions

In the present study 3D laparoscopy had better depth perception and visualization over open radical prostatectomy. The learning curve was abridged, with almost similar oncological and functional outcomes with enhanced convalescence in the laparoscopic arm. In a resource-limited setting, 3D laparoscopy can be a feasible cost-effective alternative to robotic prostatectomy.

Declarations

Conflict of interest

The authors declare no conflict of interest.