Comparing the Effects of 2D and 3D Imaging Systems on Laparoscopic Pyeloplasty Outcomes in the Treatment of Adult Ureteropelvic Junction Obstruction

Introduction

Ureteropelvic junction (UPJ) obstruction is a congenital or acquired pathology that is observed in the area where the renal pelvis is joined to the ureter and leads to a reduction in urinary flow. ¹ UPJ obstruction is the most frequent cause of high degree hydronephrosis in infants and it is observed in 1000–2000 live births.^2,3 Idiopathically, it may be observed due to reasons such as calculi or instrumentation, which is as frequent as 1/1500 adults. ⁴

In 1949, following the definition of dismembered pyeloplasty by Anderson-Hynes, ⁵ surgical treatment of the obstruction has become a method that has reached cure rates of more than 90%. ⁶ Pyeloplasty is the golden standard in the surgical treatment of UPJ obstruction, and it may be used as an open, laparoscopic, or robotic approach. ⁷

Due to the high prevalence of UPJ obstruction, many minimally invasive treatments techniques alternative to open surgery have been developed in pyeloplasty—one of the most frequent urological reconstructive interventions—to avoid disadvantages such as poor cosmetic outcomes caused by the incision scar of the open surgery, postoperative pain, and delayed recovery. ⁸ Similar to the procedure of Anderson-Hynes, in 1993, Schuessler et al. defined laparoscopic dismembered pyeloplasty for adults and took an important step in minimally invasive treatment techniques by including known principles of the open surgery. ⁹ This technique has become the first step minimally invasive treatment option for the generally accepted treatment of UPJ obstruction and has reached the success rates of open pyeloplasty in the 10-year follow-up period. ¹⁰

Laparoscopic surgery has become a preferred option for many surgeons worldwide due to various surgical and clinical benefits compared with conventional open surgery, namely less surgical trauma, rapid recovery, a lower need for postoperative analgesics, and shorter duration of hospital stays.^11,12 However, the limited mobile capacity of laparoscopic instruments, poor perception of depth in two-dimensional (2D) laparoscopic imaging systems, and the wider learning curve may be counted as the main problems encountered in laparoscopic surgery.

One of the techniques developed to solve these problems is the three-dimensional (3D) laparoscopic imaging system, which has improved the intracorporeal dissection, the suturing quality, the ergonomics, and the perception depth during laparoscopic surgery. ¹³

The aim of this study was to compare the efficacy, safety, and clinical and perioperative outcomes of 2D and 3D laparoscopic imaging systems in adult patients undergoing laparoscopic pyeloplasty in our clinics due to UPJ obstruction.

Materials and Methods

The study was commenced on approval of the local ethical committee with 30.05.2019 date and B.30.2.ATA.0.01.00/314 number. It was conducted between January 2014 and April 2021 in The Research Hospital of Atatürk University Medical Faculty Urology Clinics. A total of 46 adult patients who had undergone laparoscopic pyeloplasty due to UPJ obstruction were included in the study. Informed consent was obtained from all patients included in the study.

The indications for pyeloplasty were impaired split renal function (<40%), reduction in the split renal function in the following studies of more than 10%, poor drainage function after furosemide administration, third- or fourth-degree dilatation, or increased antero-posterior diameter on the sonography. Cases that had undergone the operation before January 2019 were investigated by using the 2D imaging systems, and the operational notes, the patient files, notes on admission, and the clinical findings at the postoperative 1st, 3rd, and 12th months were retrospectively evaluated.

After that time period, the 3D imaging systems were used, and the operative, perioperative, and early postoperative notes of the patients and the clinical findings at the postoperative 1st, 3rd, and 12th months were recorded prospectively. Two patients with a history of previous endopyelotomy and ipsilateral UPJ obstruction, 1 patient with a history of nephrolithotomy, and 2 patients with open pyeloplasty were excluded from the study. Patients undergoing laparoscopic pyeloplasty were grouped as those who had undergone imaging with the 2D system and those who had undergone imaging with the 3D systems.

To standardize the perioperative findings, the cases that were operated by a single surgeon experienced in both 2D and 3D imaging systems were included in the study. All operations were performed via the transperitoneal approach by using three ports. The brands of the imaging systems were Olympus^® for 2D and Wolf^® for 3D. The 3D imaging system included a 3D HD camera, a 3D image processor to reflect the image to a 2D/3D HD tv monitor, and a 10 mm double optic telescope of 30° in the middle. Standard, cinema type, passive 3D glasses were used in the 3D group throughout the operation.

The demographic characteristics and the clinical findings of the patients were compared between the groups. Parameters such as the duration of the operation, perioperative and postoperative complication rates, estimated amount of blood loss, rate of drain placement, time to drain removal, and the duration of hospital stay were compared between the groups.

Results

A total of 46 patients were evaluated. Two patients with a history of previous endopyelotomy and ipsilateral UPJ obstruction, 1 patient with a history of nephrolithotomy, and 2 patients with open pyeloplasty were excluded since they could affect the perioperative findings. A total of 41 patients who fulfilled the inclusion criteria were included in the study. The mean age of the participants was 27.7 ± 9.17 years. Among the patients, 23 (56.1%) were in the 2D group and 18 (43.9%) were in the 3D group.

The number of male patients was 23 (56.1%), and the number of female patients was 18 (43.9%). Right pyeloplasty was performed in 18 (43.9%) patients, and left pyeloplasty was performed in 23 patients (56,1). No statistically significant difference was observed between the groups with regard to the demographic characteristics of the patients. The demographic, clinical, and perioperative characteristics of the patients have been summarized in Table 1.

The mean duration of operation was 129 ± 26.8 minutes. The duration observed in the 3D and the 2D groups was 113 ± 14.5 and 141 ± 28.2 minutes, respectively, which was significantly shorter in the 3D group. No statistical difference was observed in the remaining perioperative and postoperative findings. The operation was completed without placing a drain in 4 patients in the 3D group. No early or late complication was observed, except for 1 patient in the 2D group in whom the drain was in situ for as long as 8 days. The demographic, clinical, and perioperative findings of the patients in the 3D and the 2D groups have been demonstrated in Table 2.

No late complication, obstruction, or recurrence was observed at the first, third, or 12th month visits of the patients in any of the groups.

Discussion

The 2D laparoscopic imaging systems include a single camera (monoscopic), which leads to a poor perception of depth. However, 3D imaging systems include two cameras (stereoscopic), one on each other's side. Images received from these two cameras are passed through an eyeglass that corresponds to each eye, filtered, and perceived as a single image. This provides an improved perception of depth. ¹⁴ Improved perception of depth has been related to higher accuracy, acceleration in the performance, and a shorter learning curve. ¹⁵

In the study of Abou-Haidar et al. comparing the 3D and the 2D systems in pediatric patients undergoing laparoscopic pyeloplasty, the duration of the operation was observed to be shorter in the 3D group. The authors mentioned that this was due to the fact that 3D images facilitated, in particular, the needle control during saturation, which reduced the time of anastomosis. ¹⁶ In the study of Xu et al., comparing the systems in 31 adult patients undergoing laparoscopic pyeloplasty, the duration of the operation was observed to be shorter in the 3D group as well. ¹⁷

In our study, we compared these two systems in adult patients undergoing the procedure and observed the same outcome, which was statistically significant. We believe that the reason for a shorter duration of operation in the 3D group was the perception of depth observed in 3D systems, and more ergonomic dissection and saturation processes. Our findings are compatible with the limited findings in the literature and are parallel to the technological advantages introduced by 3D imaging systems. To our knowledge, there is no study in the literature evaluating the durations of operations in the 2D and 3D groups separately and comparing them in laparoscopic pyeloplasty.

We believe that further studies analyzing the parts of the operations separately and evaluating the reason for the duration of the operation being shorter in the 3D group should be conducted.

The operation was completed without placing a drain in 4 patients in the 3D group. All patients underwent installment of a drain in the 2D group. No difference was observed between the groups with regard to the time for removal of the drain. The higher rate of completion of the operation without placing a drain in the 3D group, the increased perception of depth, and the more ergonomic processes of dissection and saturation may be related to a safer saturation line perceived by the surgeon.

In their study investigating the causes of biliary duct injury during laparoscopic cholecystectomies, Way et al. reported that visual misinterpretations were responsible for 97% of the surgical injuries. ¹⁸ Studies demonstrate that 3D imaging systems have improved the perception of depth, facilitated the dissection and saturation, and improved the ergonomics in laparoscopic surgeries, which, in turn, have improved the outcomes of pyeloplasties. ¹³ Further, it has been demonstrated that, independent from the surgical accidents, general anesthesia-related perioperative complications may be increased in relation to the duration of the operation. ¹⁹

Studies comparing 2D and 3D imaging systems in laparoscopic pyeloplasty have reported no significant difference between groups with regard to perioperative and postoperative complication rates.^16,17 Technological advantages and shorter duration of operation provided with 3D imaging systems used in laparoscopic pyeloplasty suggest that it would cause a reduction in surgical procedure related complications and peri- and postoperative anesthesia. However, we did not observe a significant difference in the complications evaluated according to the modified Dindo-Clavien criteria between the groups in both the perioperative and the postoperative periods.

No difference was observed between the groups with regard to the duration of hospital stay and the estimated amount of blood loss either. No early complication was observed, except in 1 patient in the 2D group in whom the drain was in situ for as long as 8 days. No late-term complication or recurrence was observed in patients followed up to 12 months in any of the groups. Absence of a significant difference between the groups with regard to complication rates may be related to the experience of our surgeon in 2D and 3D imaging systems guided laparoscopic pyeloplasty, to the inability of very low rates of complications in providing sufficient information for the statistical analysis, and to the limited number of patients included in our study.

Although we did not determine a significant difference between the groups with regard to perioperative and early and late postoperative complications, which was compatible with the findings in the literature, we believe that 3D imaging systems will indicate lower rates of complications in further large sample sized studies.

The main limitation of our study was that it was not a randomized prospective study. Another limitation was the limited number of patients included in our study.

Conclusion

The duration of the operation is significantly reduced in the 3D image-guided laparoscopic pyeloplasty operations in the treatment of UPJ obstruction of the adult, compared with 2D image-guided operations. The 3D imaging systems provide a better image quality, an important convenience in intraoperative saturation, and low rates of complications in laparoscopic pyeloplasty, and they may be used safely and effectively. Randomized prospective studies should be conducted on the subject.