Transperitoneal Laparoscopic Ureterotomy: A Mini-Invasive Option for Ureteral Stones

Background and Objective: Laparoscopy can be an alternative modality in the management of ureteral stones. We herein present our experience with laparoscopic ureterolithotomy although most ureteral stones are managed using endourologic techniques, open surgery, or shockwave lithotripsy. Materials and Methods: This retrospective study was performed from January 2014 to December 2019 on 20 patients with ureteral stones who were treated using transperitoneal laparoscopic access. We collected data on patients’ ages, gen-ders, clinical profiles, relevant medical history, sizes of the calculi, localisation of the calculi as confirmed by imaging, and outcome of lithotripsy. Continuous data were presented as mean values and standard deviations (for normally distributed data) and medians with interquartile ranges (for skewed data). Categorical data were presented as frequencies and percentages. Results: We included 20 patients (13 males and 7 females) with a mean age of 40.40 ± 13.25 years. The mean stone size was 18.5 ± 3.05 mm and all procedures were com-pleted laparoscopically. The


Introduction
Different surgical techniques have been established for the management of different types of renal stones, and the choice of a technique depends on the locations and distribution of the stones. These techniques include non-invasive and minimally invasive modalities such as ureteroscopy (URS), extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), laparoscopy, and robotic surgery [1]. Where non-invasive or minimally invasive methods are either unavailable or fail, invasive procedures (including open surgery) can be employed. The American Urological Association (AUA) recommends watchful waiting for patients with uncomplicated ureteral stones ≤ 10 mm, URS for patients with mid-or distal ureteral stones who require intervention, and for patients with suspected cystine or uric acid ureteral stones in whom medical expulsive therapy (MET) as a treatment modality for adult patients with ureteral stones fails [2]. In the case of adult patients with renal stones, the AUA recommends ESWL or URS for symptomatic patients with a total non-lower pole renal stone burden of <20 mm, PCNL for symptomatic patients with a total renal stone burden of >20 mm [3]. Laparoscopic ureterotomy (LUT) is an important alternative to percutaneous nephrolithotomy (PCNL) in the management of large (≥20 mm) ureteral calculi; however, the latter remains the gold standard [4]. LUT is usually considered in patients who have renal anomalies, are poorly compliant, and have a large single renal-pelvic calculus [5].
LUT could follow a transperitoneal or retroperitoneal approach and is usually performed under general anaesthesia. The transperitoneal approach involves insufflating the abdomen with carbon dioxide and making several small abdominal incisions. In the retroperitoneal approach, a small incision is made in the back and a dissecting balloon is inserted to create a retroperitoneal space. The stone is accessed through an incision in the ureters (ureterotomy). Once the stone is removed, the ureterotomy is usually closed with sutures, with or without a stent placement [6].
LUT, like other surgical procedures, is prone to complications. Potential complications of this technique could either be associated with the removal of the stone or with the closure of the ureterotomy incision [7]. When laparoscopic pyeloplasty with concomitant pyelolithotomy was performed on 15 patients, all of them experienced wall oedema and friability because of the use of irrigation. Also, in a series involving 16 patients who underwent laparoscopic transperitoneal pyelolithotomy as first-line treatment for pelvic stones published by Meria et al., 14 of the patients had urinary leakage as a complication [8] [9]. In this study, we aimed to present our experience with laparoscopic ureterolithotomy in 20 patients at the Centre medico-chirugicale d'urologie in Douala, Cameroon.

Methods and Materials
This was a retrospective study carried out over a period of six years (from January 2014 to December 2019) at the Centre medico-chirugicale d'urologie, which is located in Bali, Douala. This is a medical centre that specialises in minimally-invasive surgery and the surgical management of urological pathologies using innovative techniques. The study included 20 patients with large calculi at the ureters who were treated through LUT. The procedure was performed by two surgeons who operated on all 20 patients. The devices used for the laparoscopic procedures are presented in Figure 1. All patients underwent abdominopelvic CT before the procedure to localise the stones. All patients benefited did a pre-operative workup, including a full blood count, urea and creatinine, clotting profile, and urine analysis with culture. All patients with confirmed urinary tract infections prior to the intervention were treated as per the results of culture and antibiotic sensitivity profile. A second-generation cephalosporin was administered to all patients without confirmed urinary tract infections as a prophylactic antibiotic. All procedures were performed under general anaesthesia.
The patients were placed in the lateral position, and the ureter was accessed transperitoneally. After inserting the abdominal trocars, pneumoperitoneum was achieved, and the kidney and ureter were exposed. The ureter was identified,

Results
Of the 20 participants we recruited in our study, 7 (35%) were females and 13 (65%) were males. The ages of the participants ranged from 18 years to 65 years, with a median age of 40.40 ± 13.25 years. All 20 patients had kidney stones. These stones were found on the right side of the body in 12 (60%) cases and on the left side of the body in 8 (40%) cases. The stone sizes ranged from 14 mm to 25 mm, with a mean value of 18.5 ± 3.05. The imaging technique used to locate  the stones was the anteroposterior CT scan in all the patients.
The clinical presentation of the study participants was acute nephritic colic (ANC) in 16 (80%) cases, acute nephritic colic and sepsis in 2 (10%) cases, and haematuria in 2 (10%) cases. According to the VAS classification, 13 (65%) participants experienced mild pain, 6 (30%) participants experienced moderate pain, and 1 (5%) participant experienced severe pain. Double J stents were not placed in any of the patients prior to surgery; however, after surgery, drainage using a double J stent was performed in all the patients. The double J stents were removed from the bodies of the patients after a mean duration of 18.1 ± 4.34 days. The duration of the procedure ranged from 60 minutes to 130 minutes, with a mean duration of 96 ± 22.34 minutes. The duration of hospitalization ranged from 1 day to 3 days, with a mean duration of 2.05 ± 0.69. Percutaneous drainage was not performed in any of the participants. All the participants had no complications after the procedure. The stone-free rate of LUT in this study was 100%.
The estimated blood loss during the procedure ranged from 50 ml to 300 ml, with a median value of 161.75 [100 -225] ml.
Urinalysis was performed in 2 (10%) of the participants, with the germs identified being Staphylococcus pyogenes and Escherichia coli in one patient each.
The serum creatinine levels of the study participants ranged from 8 mg/L to 40 mg/L, with a median value of 11.5 [9.5 -16] mg/L. There were no complications associated with the procedure in all the patients. The characteristics of the study participants and the procedure are presented in Table 1.

Discussion
In this study, we recruited 20 participants who underwent LUT. The median age of our study participants was 40.40 ± 13.25 39.5 years, which is similar to the mean ages of 38.5 years and 37.9 years reported by Tiwari et al. [10] and Sahin et al. [11], respectively. These similarities are probably due to the similarities in the sizes of the study samples used. There were 13 (65%) men and 7 (35%) women among the 20 participants. Similar results were reported by Bokka and Jain in 2019 [12]. This is in line with the general finding that calculi are more common in men than in women [13].
Complete stone clearance was observed in all participants in our study. Şahin et al. [14] reported a similar stone-free rate of 99% despite recruiting 213 participants. Sahin et al. [11] also reported similar results; however, although their study sample (19 participants) and the demographic profile of their study participants (14 men and 5 women; mean age: 37.9 years) were similar to ours, they performed laparoscopic retroperitoneal ureterolithotomy with concomitant pyelolithotomy using flexible cystoscope through the ureterotomy site, whereas we performed just laparoscopic ureterotomy. In addition, they used holmium laser lithotripsy in 4 cases before achieving complete stone clearance in all their participants. In 2008, Shrestha et al. reported a 100% stone clearance rate three months after ureteroscopic pneumatic lithotripsy in 92 consecutive patients who had 95 ureteric stones from 2005 to 2006. However, although the stone clearance rate was 100%, the rate of complications was 51% [15], which is different from the 0% complication rate we found in our study. The difference in the rate of complications could due to the differences in the sizes of the study samples and the fact that pneumatic lithotripsy is a technique that has been associated with a relatively higher rate of complications and a relatively longer duration of the procedure in previous studies [16]. The mean hospital stay in our study was 2.05 ± 0.69 days, which is different from the 2.6 ± 1.4 days reported by Al Sayyad in 2012 [17]. This difference could be because although his technique was similar, Al Sayyad recruited fewer participants (12 patients) in his study. His participants were also older (mean age: 52.9 ± 12 years), and his patients had larger stones (≥ 20 mm). The mean hospital stay in our study was also shorter than that reported by Bayar et al. who performed laparoscopic ureterolithotomy on 20 patients in 2014 [18]. The mean duration of the intervention in our study was 96 ± 22.34 minutes. This is higher than the 86.5 minutes reported by Sahin et al. in 2016 [11] but lower than the 107 ± 49.5 minutes reported by Al Sayyad in 2012 [17]. Al Sayyad's interventions probably lasted longer because he was working on older patients who had larger stones. However, the mean duration of the intervention in our study was also lower than the 145 ± 42 minutes reported by El-Feel et al. in 2007 [19] although they used a similar technique on a similar number (25) of patients of similar age (mean age: 39.8 ± 17.5 years). We have to admit that the duration of the surgery is also in relation to the experience of the surgeon.
The estimated blood loss in our study was higher than those reported by El-Feel et al. [19] and Şahin et al. [14]. This can be explained by the fact that in our study, the dissection was rendered difficult by the presence of many surgical adhesions due to inflammation caused by long-term and big calculi and can explain our results. However, our study had a few limitations. First, our sample size was small. This is mainly because patients in our context still consider laparoscopic procedures to be experimental; as such, they tend to opt for open surgery and shun laparoscopic procedures. Second, the retrospective study design means that there was recall bias. In spite of its limitations, this study on laparoscopic ureterolithotomy is the first of its kind in our context. We believe that with the findings of our study, the efficacy and safety of this technique will be better appreciated and it will attract the interest of policymakers, physicians, and patients, leading to its integration as part of routine healthcare in our context.

Conclusion
Laparoscopic ureterolithotomy is an effective and safe technique in the management of ureteric stones. The benefits of this technique include minimal postoperative morbidity, short postoperative hospitalization, a short convalescence period, and remarkable cosmetic results.