Introduction

Laparoscopic nephrectomy was first performed in 1990 by Clayman.  The laparoscopic approach for nephrectomy has since gained widespread acceptance, both for benign and malignant disease, as well as for donor nephrectomy.  The following CPT codes are currently in place for nephrectomy:

• nephroureterectomy (50548)
• radical nephrectomy (50545)
• partial nephrectomy (50543)

Generally, the principles of cancer surgery are not compromised by the laparoscopic approach as shown by a number of studies (1,2).  In addition, there is evidence in a randomized, controlled trial of open versus laparoscopic nephrectomy, that there may be functional benefits in the laparoscopic approach (3).

 

Credentialing for Laparoscopic Nephrectomy

When considering surgery for the kidney, the boundries between urology and general surgery are blurred.  General surgeons can and do perform kidney surgery in the form of donor nephrectomies for transplant, as well as in trauma to the kidney.  While the discussion of turf will vary from region to region, and by institution, a general hypothetical scenario in a given practice environment is that once a general surgeon begins treating renal cancer and other renal disease through surgery, it will likely attract the attention of the Chief of Urology.  The argument on the side of urology is that urologic procedures beget urologic complications, and may require the expertise of a urologist to manage such complications.  This can impact the willingness of a urologist to provide help in the case of complications, if they feel their turf as been infringed upon.

Credentialing is defined at the hospital level.  The relevance of a general surgeon to a particular practice environment will determine whether they should seek credentials in urologic procedures or not.  In some cases, a general surgeon may be required to assist a urologist in more difficult procedures or for exposure.

 

Transperitoneal versus Retroperitoneal Approach

This will depend on the confort level of the surgeon.  The question of transperitoneal versus retroperitoneal approach has no particular oncologic import.  The default approach to laparoscopic nephrectomy is facing the patient’s abdomen with the patient in the lateral decubitus position, and approaching the kidney through a transperitoneal approach.

 

Surgical Strategy for Renal Malignancy

Transitional cell cancers behave more aggressively than renal cell tumors and the full field of transitional epithelium must be resected, including the bladder cuff if the tumor is in the ureter.  The biologic aggressivelness of these tumors is clear from reports of port site tumor implants and recurrence following laparoscopic resection, which highlights the need for meticulous surgical technique (4,5).  Renal cell tumors can be locally excised provided margins are clear and there is a growing trend to nephron sparing surgery in most cases of small (<4 cm), localized masses regardless of whether the traditional indications of prior nephrectomy or bilateral tumors are present.  Some groups are even performing partial resections for centrally based tumors (6).  Overall survival after removal of small, node negative, M0 renal cell cancers is better than 99% at three years.  Open partial nephrectomy is now well accepted.  The more challenging laparoscopic partial nephrectomy is less widely available but in the absence of clear EBM guidelines for its use, concerns have been expressed that partial nephrectomy may be underutilized in favor of radical laparoscopic resection.  However, a recent study does not support this criticism (7).

Conceptually, nephrectomy is a simple ablative procedure.  Control of the vascular pedicle, division of the ureter and removal of the kidney from its anatomic bed are not complicated requirements.  Preoperative identification of unfavorable tumor biology such as renal vein or caval extension, choice of approach and exposure, early interruption of the lymphovascular pedicle, perservation of the tumor envelope and radical extirpation of perirenal fat with or without ipsilateral adrenal distinguish resection for ancer from surgery for benign diseases.

In one way, nephrectomy for tumor is easier than simple nephrectomy, in which the kidney is shelled out of its fatty envelope. Experience with laparoscopic donor nephrectomy taught us that intentionally leaving intact the perirenal fat shrouding the capsule and dissecting in the plane between fat and muscle actually simplified the operation.  Fewer injuries such as capsular cracks, parenchymal punctures or capsular vessel avulsion occurred.  No vessels other than the main pedicle traverse the plane and blood loss for this part of the procedure is essentially eliminated.  In any case, for cancer, leaving the perirenal fat, and if the tumor is exophytic, taking a generous amount of surrounding tissue, is warranted.

 

When, Where, and How are the Vessels Divided?

A fundamental axiom of cancer surgery is early interruption of the lymphovascular pedicle.  There may not be much science to support what is basically good housekepping, but in the case of renal cell cancer, it is particularly relevant because of the tendency of the tumor to grow out of the kidney within the renal vein.  Recent imaging of the kidney is preferable to plan the optimal approach.  On the left, the tumor has a lot further to grow and considerable time can elapse before the tumor reaches the cava.  On the right, the vein is very short and the importance of a recent scan to show tumor extension is greater.  It is better to decide in advance if a tongue of tumor ascending the cava will require the help of a vascular surgeon to retrieve and that a laparoscopic approach is not appropriate.

The anatomic landmarks (renal vein, ureter, adrenal gland) are fairly simple to find in slim patients but as is often the case in the North American population, perirenal fat is abundant.  It is essential to have a reliable technique that will faciliate localization of the renal vein accurately.  Unlike the ureter which does not fight back and can eventually be sacrificed, the renal vein will reward a clumsy dissection with frighteningly brisk hemorrhage that can quickly lead down a perilous path.

On the left, you need to know how to peel mesocolon from the hilum and ureteric bundle and stay in the correct avascular plane.  Once that is done, if you do not know how to come straight down onto the renal vein, or cannot see its bluish tinge through the hilar fat, find it by following the gonadal vein cephalad.  The gonadal vein is usually easy to find parallel to the inferior mesesnteric vein but in its own separate compartment. Preoperative imaging should have defined the number and position of the arteries and these should be interruped first.

The safest and most secure way to divide artery or vein is to clip or staple it with a non-cutting stapler first, inspect the completeness of the clip or staple line and then divide.  If clipping, at least two locking plastic clips (Hemolock) should be applied.  If metal clips have been used in any part of the dissection, it is wiser to avoid use of a stapler lest the jaws be inadvertently closed on a clip during application of the stapler, causing a misfire.  After location and preliminary dissection, the artery should be ligated first, if just with a single clip to prevent any further inflow.  The vein itself should be carefully palpated with the finger to ensure it does not contain tumor before proceeding.  The surgeon’s attention can then focus on accurate exposure, circumferential dissection, ligation and division of the vein.  This order of events makes exposure of the artery easier.

Hand Assist or Not?

There may be an advantage to having an extraction incision that is a similar length as a hand part, for tumors 7-8 cm or greater.  Although the strength and cellular imperviousness of retrieval bags have made morcellating cancers to remove them through a laparsocopic port site safer, there is still a risk of tumor spill.  also, morcellation may prevent accurate staging of small but advanced pT(3a) lesions (8).  Very large tumors may be more difficult to maneuver with straight laparoscopic instruments.  Pressure on the mass with a straight instrument shaft will working around a corner may crack the kidney or tumor.  A hand in the field confers obvious proprioceptive and geometric advantages to the three dimensional operative tasks of retraction, dissection, and mobilization deprived by degrees of freedom by the fixed fulcra of laparoscopic entry points.

 

Total or Partial Nephrectomy?

Partial nephrectomy when performed with vascular isolation is a challenging procedure and is not usually within the scope of a general surgeon.  What many urologists actually perform is more precisely a tumorerctomy with margin, similar to non-anatomic resection of a liver metastasis.  Indeed small tumors located in an upper or lower pole can often be treated this way.  Large centrally located tumors usually require total nephrectomy to achieve an adequate margin because of proximity to hilar vessels although with experience smaller tumors in this site can be successfully resected (6).  Positive margins may necessitate comopletion of a radical nephrectomy as shown by a large multi-center study (9).  Laparoscopic partial resection while realizing the predicted benefits of reduced pain, blood loss, operative time and hospital stay was associated with greater morbidity than open surgery (10).

 

With or Without Adrenalectomy?

It is not necessary to remove the adrenal if an adequate margin is achieved by partial or total nephrectomy, as for example with a lower pole tumor.  Exophytic renal tumors that are contiguous with or adjacent to the adrenal on preoperative imaging should be removed within the envelope of Gerota’s fascia.  This standard may need to be modified if the patient has had a contralateral adrenalectomy.

 

Advanced Surgical Permutations

When nephron sparing is paramount in an unfavorably sited cancer that would be too difficult to remove in situ, other possibilities include laparoscopic nephrectomy, back table removal of the tumor and autotransplantation or allograft transplantation (11).

 

References

1.  Eskicorapci SY, Teber D, Schulze M, Ates M, Stock C, Rassweiler JJ. Laparoscopic radical nephrectomy: the new gold standard surgical treatment for localized renal cell carcinoma. Scientific World Journal. 2007. 7. 825.36.

2.  Gong EM, Shalhav AL. Laparoscopic managment of renal tumors. Clin Genitourin Cancer. 2007. 5(5): 306-17.

3.  Burgess NA, Koo BC, Calvert RC, Hindmarsh A, Donaldson PJ, Rhodes M. Randomized trial of laparoscopic versus open nephrectomy. J Endourol. 2007. 21(6): 610-3.

4.  Muntener M, Schaeffer EM, Romero FR, Nielsen ME, Allaf ME, Brito FA, Pavlovich CP, Kavoussi LR, Jarrett TW. Incidnece of local recurrence and port site metastasis after laparoscopic radical nephroureterectomy. Urology. 2007 70(5): 864-8.

5.  Araki M, Lam PN, Fetzer AE, Clair DL, Wong C. Tumor recurrence incidence following hand-assisted laparoscopic nephroureterectomy. JSLS. 2007. 11(4): 449-52.

6.  Richstone L, Montag S, Ost M, Reggio E, Permpongkosol S, Kavoussi LR. Laparoscopic partial nephrectomy for hilar tumors: evaluation of short-term oncologic outcome. Urology. 2008. 71(1): 36-40.

7.  Perotti M, Badger WJ, McLeod D, Prater S, Moran ME. Does laparoscopy beget underuse of partial nephrectomy for T(1) renal masses? Competing treatment decision pathways may influence utilization. J Endourol. 2007. 21(10): 1223-8.

8.  Granberg CF, Krambeck AE, Leibovich BC, Frank I, Lohse CM, Gettman MT, Blute ML, Chow GC. Potential underdetection of pT(3a) renal-cell carcinoma with laparoscopic morcellation. J Endourol. 2007. 21(10): 1183-6.

9.  Breda A, Stepanian SV, Liao J, Lam JS, Guazzoni G, Stifelman M, Perry K, Celia A, Breda G, Fornara P, Jackman S, Rosales A, Palou J, Grasso M, Pansadoro V, Disanto V, Porpiglia F, Milani C, Abbou C, Gaston R, Janetscheck G, Soomro NA, de la Rosette J, Laguna MP, Schulam PG. Positive margins in laparoscopic partial nephrectomy in 855 cases: a multi-institutional survey form the United States and Europe. J Urol. 2007. 178(1): 47-50.

10.  Gill IS, Kavoussi LR, Lane BR, Blute ML, Babineau D, Colombo JR Jr, Frank I, Permpongkosol S, Weight CJ, Kaouk JH, Kattan MW, Novick AC. Comparison of 1800 laparoscopic and open partial nephrectomies for single renal tumors. J Urol. 2007. 178(1): 41-6.

11.  Whitson JM, Stackhouse GB, Freise CE, Meng MV, Stoller ML. Laparoscopic nephrectomy, ex vivo partial nephrectomy followed by allograft renal transplantation. Urology. 2007. 70(5): 1007.e1-3.