Laparoscopic Vs Open Anatrophic Nephrolithotomy Operative Outcomes and Comorbidities

Even in this modern era of endourology where we have experienced mayor technological advances and technical improvements, management of staghorn calculi remains a big challenge especially in obtaining a stone-free status with low morbidity. By definition staghorn calculus occupies more than 80% of the collecting system or the renal pelvis and more than one single calyx [1]. It is not uncommon that a stone free status for a staghorn calculus is not achieved after several sessions with endourological techniques and even after an open, laparoscopic or robotic surgery. In past decades percutaneous nephrolithotomy (PCNL) and shock wave lithotripsy (SWL) have revolutionized renal calculi management. It is because of its minimally invasive nature and high effectiveness with less morbidity that they have replaced open surgery for big renal calculi treatment. Nowadays, PCNL it is the first line treatment for renal calculi >2cm and for those in lower renal pole >10mm. However, in big renal calculi (staghorn calculi) PCNL could not get a stone free status even with more than one procedure [2]. Stone free rates for anatrophic nephrolithotomy (AN) could not be


Introduction
Even in this modern era of endourology where we have experienced mayor technological advances and technical improvements, management of staghorn calculi remains a big challenge especially in obtaining a stone-free status with low morbidity. By definition staghorn calculus occupies more than 80% of the collecting system or the renal pelvis and more than one single calyx [1]. It is not uncommon that a stone free status for a staghorn calculus is not achieved after several sessions with endourological techniques and even after an open, laparoscopic or robotic surgery.
In past decades percutaneous nephrolithotomy (PCNL) and shock wave lithotripsy (SWL) have revolutionized renal calculi management. It is because of its minimally invasive nature and high effectiveness with less morbidity that they have replaced open surgery for big renal calculi treatment. Nowadays, PCNL it is the first line treatment for renal calculi >2cm and for those in lower renal pole >10mm. However, in big renal calculi (staghorn calculi) PCNL could not get a stone free status even with more than one procedure [2]. Stone free rates for anatrophic nephrolithotomy (AN) could not be depended on nephrolitometric mesurements like PCNL does and could reach success rates of 75-95% in a single procedure, this is the reason why in many centers AN continue to be a very attractive therapeutic option in patients with sthaghorn calculi [3,4]. Laparoscopic surgery has been used to replicate different open surgeries used for ureteral and renal stones management. Laparoscopic anatrophic nephrolithotomy (LAN) has been described as an effective, safe and reproducible method in experienced centers, however, it presents higher rates of complications compared to PCNL, and higher renal function loss (7-27%) in the affected kidney but could be less invasive and more effective than open anathrophic nephrolithotomy [4][5][6].

Material and Methods
A case-control study was carried out to compare laparoscopic to open nephrolithotomy. With this purpose all patients diagnosed with staghorn calculi that were undergone to laparoscopic or open anatrophic nephrolithotomy (OAN) at ''The Antiguo Hospital Civil de Guadalajara", between 2014-2015 were included. Laparoscopic surgeries were performed by the same surgeon and open surgery was performed by 2 different surgeons. All patients were admitted the day before their surgery because of the administrative protocol of our hospital and all the patients received preoperative antibiotic prophylaxis. We performed the statistical analysis in STATCALC of Epi info 7and perform descriptive analyzes taking into account measures of central tendency and dispersion. The inferential analysis was performed using contingency tables (2x2) and x2 was calculated using the corrected Yates test. We performed the OR test, obtaining its value and as hypothesis test the confidence interval of 95%.

Laparoscopic technique
After general inhaled anesthesia a double ''J'' catheter was placed in all cases at the beginning of surgery in lithotomy position and then the patient was positioned in a lateral decubitus position. For left sided surgery we used 4 trocars and for right sided surgeries we added an extra 5mm trocar. First we place a 10mm trocar for a 30 degrees lens at the level of a imaginary pararectal line 3-4cm above the navel, then we place a second 10mm trocar at 8-9cm right sided of the first trocar, a third 5mm trocar is placed 8-9cm left sided of the first one trying to making up an imaginary triangle by these first trocars. Finally a fourth trocar is placed on the posterior axillary line as a support for renal retraction and If the procedure is on the right side an additional 5mm trocar is placed to retract the liver.
A transperitoneal approach was performed in all patients and the first step once all trocars are placed in their right position it is Told's fascia dissection and colon movilization. Then all anatomical structures such as duodenum or liver (if a right sided surgery), are dissected until renal hilum get adecuately exposed to be clamped. We continue with dissection of anterior and posterior perirenal fat until renal capsule get completely discovered and having adequate exposure of both sides of the kidney and renal hilum. Renal artery (only) get clamped with a bulldog clamp and the pneumoperitoneum pressure it is increased until reach 20mmHg to reduce risk of bleeding, a pneumoperitoneum pressure of 14mmHg the set for the rest of the surgery (Figure 1). A laparoscopic scalpel (blade number 11) to perform the incision in renal parenchyma. Incision was performed (3-4cm) trying to identify the avascular Brödel line in the kidney, a difficult issue because it is not a straight line and it has irregularities in its path [7]. Once the collector system is opened and the stone is exposed (Figure 2), an alice clamp is introduced to release the stone, always trying to remove it in one piece ( Figure 3). Collector system is then explored with the 30 degree lens for residual stone. As a final step prior to removal of the bulldog clamp, the renal parenchyma is closed with 2-0 polyglactin with a hem-o-lock reinforcement ( Figure  4). We remove bulldog clamp and hemostasia is controlled but if bleeding is observed, «X» suture points were placed as much as necessary, thereafter gelfoam ( Figure 5) were placed at the site of the renal parenchyma incision. It is very important to keep warm ischemia time to a maximum of 30 minutes because prolonged ischemia causes a greater renal damage [7]. As a last step we introduced the stones in a bag ( Figure 6). Then Jackson-Pratt type drainage was left in place.       prolonged ischemia, in the OAN group an average of 33 minutes (OR 10, p=>0.05) was obtained, a patient was excluded from this parameter because a vascular injury at the moment of placing bulldog clamp, we decided to perform nephrectomy in this patient. The blood loss in the LAN group was 218.7ml and in the OAN group 837.14ml, with a percentage of transfusion for the LAN group of 0% and 57% respectively. The complications were classified as immediate complications: trans operative nephrectomy which represented 12.5% LAN group (one patient) and OAN group 14.2% (one patient), in the LAN group no splenic lesion was reported in OAN group one patient that represents 14.2%, ureteral lesion 0% in the LAN group and 14.2% OAN group (one patient), vascular injury (cava vein) 0% in LAN group and 14.2% OAN group. Late complications were present only in one patient in the LAN group, who presented at the emergency room with hematuria 9 days postoperatively, which did not yield to medical treatment, and performed emergence nephrectomy (OR .25, p=>.05) . The free stone rate, which was demonstrated with a simple tomography before hospital discharge, was 75% for LAN group was and 42.8% for OAN group (OR 2.25, p=<0.05). Hospital stay were lower for the LAN group, mean of 3.5 days, and for the OAN group, 6.1 days (OR 6, p=>0.05). (Table 2 & 3).

Discussion
Nowadays the treatment of choice for renal stones >2cm is PCNL [9,10]. In 1968 smith and Boyce first described anatrophic nephrolithotomy but recently with the technology and urologic advances this technique had lost popularity. AN could be considered in some situations like these: failed endourological procedures, anatomical variations of the collecting system that difficult the percutaneous nephrolithotomy, neccessity of anatomical reconstruction of an uretero-pelvic junction structure, surgeon experience and trainin and skeletal abnormalities [11,12]. Reports has been shown that open surgery presents higher comorbidities compared to PCNL [13,14].
Melissourgos et al. [15] reported for open surgery a mean operation time of 180 minutes, 500ml blood loss and transfusion rate of 8.3% (2 patients), mean hospital stay 8.2 days, they made to 9 patients DMSA to determinate pre and post operative renal function and they observe that they loss only a 4% of function, stone free rate 83.3% [15]. We made a comparison between this results (Table 4). all the studies we compared was 139-192 minutes, the ischemia range was 20.8-32.8, the stone diameter range 67.3-52mm, and the complications they report urinary leakage and vascular fistula [16][17][18] (Table 5). Based on our analysis the stone free rate in a single staged procedure has better results with laparoscopic surgery than to open surgery.

Conclusion
Laparoscopic nephrolithotomy seems to have a higher stone free rate, less complication, warm ischemia time and hospital stay compared to open surgery. LAN could be a therapeutic option for renal staghorn calculi with high stone free rates in a single procedure in selected patients that are no candidates for PCNL, in centers with experience in laparoscopic surgery or those that PCNL is not available. However larger caser series and prospective studies are needed to compare all therapeutic options including PCNL and confirm these results.