Percutaneous nephrolithotomy vs laparoscopic ureterolithotomy for large upper ureteral stone: A review article

Abstract

To investigate the best treatment option for large upper ureteral stone, percutaneous nephrolithotomy or laparoscopic ureterolithotomy. We searched three key word of upper ureteral stone, laparoscopic ureterolithotomy, percutaneous nephrolithotomy in PubMed, Scopus and Ebsco. We found approximately twenty suitable articles about this subject since January 1980 until January 2014. All articles studies and reviewed meticulously and brief review of these articles was written and some Ideas of experts was added. In many studies, it is suggested that success rate and complications of laparoscopic ureterolithotomy and percutaneous nephrolithotomy are the same, but percutaneous nephrolithotomy has less hospital stay time, duration of surgery and it is more cost effective. Overall it seems that percutaneous nephrolithotomy for treatment of upper ureteral stones is preferable rather than laparoscopic ureterolitothomy

Key Words: Upper ureteral stones; Percutaneous nephrolithotomy; Laparoscopic ureterolithotomy; Laparoscopy; Ureteral calculi

Core tip: It’s an honor to write a prestigious editing board; there is a review article study to compare between percutaneous nephrolithotomy and laparoscopic ureterolithotomy for treatment of large upper ureteral stones. These two procedures are different in many aspects and it’s not clearly defined that which one is preferred option.

INTRODUCTION

Large impacted upper ureteral calculus defined as a stone that is located above the rim of pelvic Inlet bone. Upper ureteral stones may be single or multiple and may be associated with kidney stones.

The best treatment modalities for large proximal ureteral stones are not well defined[1] and include extracorporeal shock wave lithotripsy, ureterolithotripsy, percutaneous nephrolithotripsy, laparoscopic ureterolithotomy and open surgery. For large upper ureteral stones, both percutaneous and Laparoscopic ureterolithotomy are possible less invasive modalities, but how we can choose one of these two procedures, is not clearly defined.

The aim of this review article study is to compare between two main approaches to this stones that are percutaneous nephrolithotomy (PNL) and Laparoscopic nephrolithotomy.

RESEARCH

This review was conducted on a request from Baishideng Group. For this study we searched all full text papers indexed in three major resources of medical literature (PubMed, Scopus and Ebsco) using the following key words: Upper ureteral stone, laparoscopic ureterolithotomy and percutaneous nephrolithotomy. We defined large upper ureteral stones as a stone larger than 1 cm.

All papers fulfilling these inclusion criteria were included: (1) Involving treatment of large proximal ureteral stones; (2) Published between Jan 1980 and Jan 2014; and (3) If several studies were reported by the same center and authors, the most recent publication was included in writing of this review. Commentaries and case reports were excluded. After a rapid scan of the literature, ultimately 21 articles were found to be relevant to these criteria and used for compiling this review article.

DISCUSSION

Upper ureteral stones are a prevalent problem. There are many different treatment modalities that include medical expulsive treatment, shockwave lithotripsy, ureteroscopic stone extraction; PNL and laparoscopic ureterolithotomy. In large upper ureteral stones, PNL and laparoscopic ureterolithotomy are the two main approaches reported in the literature. Indications of these two procedures are nearly same and include large upper ureteral stone that is resistant to shock wave lithotripsy and stones that are not suitable for other treatment modalities. Contraindications are also not specific and are the same general contraindications for laparoscopy and PNL. These two procedures may be compared in many different aspects such as invasiveness, cost, learning curve, complications, success rate, duration of surgery and hospital stay. Therefore the choice between two modalities for each given patient would only be prudent once these differences have been taken into account.

For the ureteral stone accompanied by complex kidney stones that need surgery, PNL is the modality of choice. In upper ureteral stones located at a reasonable distance from the uretero pelvic junction [i.e., close to the ureteropelvic junction (UPJ)] and accessible from the renal pelvis too, PNL is preferred[2].

But if the stone is located far from the UPJ, the surgeon must first displace the stone from its position at the upper ureter into the pelvis, and then perform routine PNL. This approach, commonly termed push-back PNL is the alternative to laparoscopic ureterolithotomy.

In one study, Li et al[3] evaluated stone location based on vertebral level. They concluded that if a ureteral stone is located higher than the upper border of the fourth lumbar vertebra, it is inappropriate for ureteroscopic lithotripsy and should be treated by another treatment modality such as PNL or laparoscopy. In their study, stone free rate for PNL was 96.4%. Mean operation time and post operative hospital stay were 108.78 min and 2.49 d respectively[3].

For the upper ureteral stone accompanied by kidney stones, Xiong et al[4] conclude PNL to be the reasonable choice for stone treatment, In their study, they performed PNL on 108 patients with kidney and upper ureteral stones. Stone clearance rate was 99.1%, hemoglobin decrease was 4.8 ± 2.7 g/L and no blood transfusion was needed[4].

PNL is a trans-parenchymal procedure, but in laparoscopic ureterolithotomy, the kidney remains intact. This difference between the two approaches has been underlined by some authors, stating that they may theoretically expect bleeding and kidney injury to dominate in PNL compared to laparoscopic ureterolithotomy. In reality, in uncomplicated PNL, bleeding is not significant. Lang[5] reported their post PNL transfusion rate to be 0.43%.

Through the unavoidable step of tract dilation, PNL inherently causes some renal parenchymal invasion. Renal dimercapto succinic acid scans performed to assess the state of cortical function at varying intervals post op, shall reveal focal cortical defects at the point of access, but at the same time usually confirm that as result of the removal of obstructive stones, overall renal function will be preserved or even improve in the post operative scan after PNL[6].

In laparoscopic ureterolithotomy it is clear that the procedure does not involve direct parenchymal trauma. In one study Yasui et al[7] evaluated the impact of laparoscopic ureterolithotomy on renal function by performing renal scintigraphy using 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) before and 3 mo after surgery. Ultimately they conclude that pre-operative and post-operative affected renal function images shown no significant change in MAG3 clearance[7].

One of the most important positive aspects of choosing laparoscopy for the treatment of large upper ureteral stones is its high success in achieving stone free state. This has been confirmed by several studies in which success rates were reported to stand between 96% to 100%[8-10].

Some factors may hamper the success of laparoscopic ureterolithotomy including severe fibrosis and tissue adherence surrounding the ureteral stone site. This can make dissection very difficult and occasionally impossible, and these factors are limitations of laparoscopic ureterolithotomy especially in retroperitoneal route[11].

Another complication of laparoscopic ureterolithotomy that directly impacts its success is upward displacement of the ureteral stone into the renal pelvis. Upward migration may preclude laparoscopic access to the stone. This situation can occur when a non-impacted stone is located close to the UPJ and the adjacent proximal ureter is very dilated. In such a circumstance, it’s better to switch the treatment plan to push-back PNL. Several studies have reported the success rate for push-back PNL between 82.8% and 99.1%[4,12,13].

Regarding the approach to the kidney for percutaneous treatment of upper ureteral stones, there is essentially two ways to reach the stone. One is by creating access through a tract from superior calyx. Upper ureteral stones are readily accessible via this approach, provided the ureteral segment proximal to the stone is dilated enough to permit navigation by the nephroscope[13].

The second approach is push-back PNL. For this purpose the stone must first be displaced from the upper ureter into the renal pelvis by retrograde ureteroscopy, followed by obtaining a routine subcostal inferior calyx access for PNL. But at times the stone is tightly impacted. This renders the push-back strategy difficult and even perilous. Precisely such impacted ureteral stones should better be approached electively by laparoscopic ureterolithotomy, as push-back PNL is apt to fail.

In comparing the two surgical procedures, duration of anesthesia and surgery have also been evaluated in several studies. All allude to the slightly lengthier approach being laparoscopic ureterolithotomy which takes anywhere between 45 and 190 min on average[14-18]. Laparoscopic ureterolithotomy is fairly time consuming, while push-back PNL is relatively quicker. Upper ureteral stones chosen for push-back PNL were usually solitary. This might have contributed to the observation that in many small studies, push-back PNL takes between 30 to 160 min[3,4,12,19].

Duration of hospital stay is an important consideration. Most health systems favor limiting hospital stay as a strategic objective to help lower the financial burden of treatment. In PNL, the duration of hospital admission has been reported between 12 and 96 h[12,20]. For laparoscopic ureterolithotomy this period spans between 1 and 6 d[10,14,16] (Table 1).

Table 1 Summary of some characteristics of two treatment modality for large upper ureteral stones: Laparoscopic ureterolithotomy, push back percutaneous nephrolithotomy.

	Laparoscopic ureterolithotomy	Pushback PNL
Stone free rate range (%)	96.5-100	82-99
Operation time range (min)	45-190	30-160
Hospitalization time (h)	24-144	12-96
Transfusion rate average (%)	Rare	0.43

PNL: Percutaneous nephrolithotomy.

Another aspect of any less invasive surgery is the direct cost of such procedures which generally require advanced equipment and disposable devices, in addition to trained surgeons and operating room staff. This factor has not been covered in any of the papers contributing to this article.

CONCLUSION

Both laparoscopic ureterolithotomy and push-back PNL can be used for treating large upper ureteral stones.

These two modalities are similar in many aspects such as success rate and complication rate; but differ in such areas as duration of anesthesia and hospital stay, indirectly leading to treatment cost. As result it appears that push-back PNL is slightly favorable over laparoscopic ureterolithotomy for treating large upper ureteral stones.