You need to log in to watch this media!

Click here to log in.

Pediatric partial nephrectomy via retroperitoneal approach

Authors

Abstract

The description of the Pediatric partial nephrectomy via retroperitoneal approach covers all aspects of the surgical procedure used for the management of (description de la pathologie en cause).
Operating room set up, position of patient and equipment, instruments used are thoroughly described. The technical key steps of the surgical procedure are presented in a step by step way: Introduction, Anatomy, Indications, Operating room set-up, Trocars/instruments, Trocar placement, Dissection of kidney, Upper pole nephrectomy, Extraction, Postop period, Reference.
Consequently, this operating technique is well standardized for the management of this condition.

Media type

Publication

2003-03

Popular

Favorites

Audio

E-publication

WeBSurg.com, Mar 2003;3(03).
URL: http://www.websurg.com/doi-ot02en288.htm

Pediatric partial nephrectomy via retroperitoneal approach

1. Introduction

Retroperitoneoscopy refers to the minimally invasive approach to the retroperitoneal space, developed in the early 1990s (Gaur et al., 1993; Gaur, 1995). Due to cosmetic, functional, and immunologic advantages, this approach has been gaining popularity for pediatric urologic procedures involving the upper urinary tract, which are usually approached retroperitoneally. However, compared to transperitoneal laparoscopy, retroperitoneoscopy has the disadvantage of a smaller working space, especially in children. This can hinder trocar placement and mobility. Some advantages include the avoidance of postoperative paralytic ileus, intestinal adhesions, and omental eviscerations. Retroperitoneoscopy also simplifies the approach to the kidney, which is subsequently not obstructed by the intra-abdominal organs, especially the bowel.

Retroperitoneoscopy has become an approach of choice for minimally invasive surgery of the kidney, ureters, adrenal gland and, in some cases, the aorta (Clayman et al., 1991). Unlike the peritoneal or pleural cavity, the retroperitoneal space is not an actual anatomical space. It therefore requires the creation of a 'neocavity' to obtain adequate working space.

Retroperitoneoscopy has also been shown to be a feasible approach for partial nephrectomies (Winfield et al., 1993). This chapter describes the technique for upper polar nephrectomy. Patient positioning and exposure are not significantly different for lower polar nephrectomy.

2. Anatomy

• Anterior relationships

The kidneys are covered anteriorly by perirenal fat and the posterior parietal peritoneum with intraperitoneal contents.
- right kidney:
1. Inferior surface of liver
2. Second portion of duodenum
3. Hepatic flexure of colon
- left kidney:
4. Tail of pancreas
5. Inferior surface of spleen
6. Splenic flexure of colon

• Posterior relationships

1. Psoas muscle
2. Quadratus lumborum muscle
The posterior surface of the kidneys lies on a muscular plane comprised of the psoas muscle medially and the quadratus lumborum muscle laterally.

• Duplex kidney

1. Renal parenchyma
2. Superior collecting system
3. Inferior collecting system
4. Common periureteral sheath
5. Common renal pedicle
6. Vascular pedicle of superior pole
7. Vascular pedicle of inferior pole
When there is duplication of the ureter (duplex kidney) there are 2 ureteral orifices on the right or on the left, with 2 ureters and 2 renal pelvises. Duplex kidney consists of a single renal body with 2 distinct collecting systems, each with its own ureter. The inferior collecting system, which drains the middle and inferior calices, is usually the larger one. The vasculature is variable, but there is usually a separate vascular pedicle for each pole, originating from a common renal pedicle.
The 2 ureters course in the same periureteral sheath with a common vascular supply, and then converge in cases of ureteral duplication. In cases of pyelo-ureteral duplication, they enter the bladder separately.

3. Indications

Upper polar nephrectomy is indicated for dysplasic upper renal collecting systems destroyed by an obstructive pathology (ureterocele or ectopic ureter). Lower pole nephrectomy is mainly indicated for vesicoureteral reflux.

Relative contraindications are the same as those for a total nephrectomy:
- recent episodes of pyelonephritis;
- xanthogranulomatous pyelonephritis;
- history of severe renal trauma that could lead to difficulties in dissection and in the creation of a working space.

4. Operating room set-up

• Patient

The child is placed in lateral decubitus position, on a lumbar support or an angulated table to open the working space between the 12th rib and the iliac crest.
Depending on the patient’s weight and age, either wide adhesive tape or cushions are used to prevent the body from moving.
Pressure points are protected.

• Team

1. Surgeon
2. Assistant
3. Scrub nurse
The surgeon and assistant stand behind the patient.
The surgeon stands at the feet and the assistant stands at the head of the patient during the vascular approach and freeing of the kidney. There may be a change in positions during the ureterectomy.

• Equipment

1. Video unit
2. Instrument table
3. Electronic devices (electrocautery, ultrasonic scalpel), suction-irrigation device
4. Anesthetic equipment
The video unit is located opposite the surgeon and assistant, at the level of the patient’s head.
It must be possible to move the video unit down toward the patient’s feet during the procedure (ureterectomy).

5. Trocars/instruments

• Optical

1. Mid-axillary line
2. Sacro-lumbar paravertebral muscles
3. 12th rib
4. Iliac crest
A 10 or 12 mm trocar is inserted at the tip of the 12th rib.

• Operating trocars

• Posterior

A 5 or 3 mm trocar is positioned on the lateral edge of the sacro-lumbar muscles, 2 to 3 cm above the iliac crest, to allow for adequate mobility of the instruments.
This trocar accommodates:
1. Grasping forceps
2. Atraumatic graspers
3. Dissector
4. Ultrasonic dissectors
5. Bipolar forceps
6. Ultrasonic scalpel
7. Suction-irrigation device

• Anterior

A 5 mm trocar is introduced on the mid-axillary line, 2 to 3 cm above the iliac crest. It accommodates:
1. Grasping forceps
2. Dissector
3. Scissors

• Posterior superior

An optional fourth trocar may be required during dissection. It is placed on the lateral edge of the sacro-lumbar muscular mass, below the angle of the 12th rib. It accommodates:
1. Grasping forceps
2. Dissector
3. Scissors

6. Trocar placement

• Optical trocar

1. Kidney
2. Parietal peritoneum
3. Psoas major muscle
4. Kelly forceps
5. Beginning of dissection
After making a 10 to 12 mm incision at the tip of the 12th rib, the musculofascial planes are dissected and exposed using Farabeuf retractors with a long, narrow blade. The fascia and perirenal fat are incised. A gauze wad (about 8 mm) placed on a Kelly forceps is introduced. The dissection begins with the gauze wad, caudally and posteriorly, until the anterior surface of the psoas major muscle is reached. The dissection is then continued along this muscle, as inferiorly as possible. The detachment is carefully pursued anterior to the psoas major muscle, permitting retraction of the parietal peritoneum.
A 10 mm trocar is placed. A purse string is fashioned. The trocar is attached to the wall by a suture to prevent gas leak and to exert traction on the wall, as is done in parietal suspension techniques.
A 10 mm, 0° laparoscope is introduced.
The laparoscope is introduced and the pneumodissection of the retroperitoneal space can begin, following the plane of the psoas major muscle.

• Posterior trocar

1. Creation of working space
2. Electrocautery scissors via posterior trocar
3. Anterior surface of psoas major muscle
The posterior operating trocar is introduced as soon as possible. After making the skin incision, a fine grasper (Kocher or Halstead) creates a passage in the musculofascial plane under laparoscopic guidance, enabling the surgeon to safely place the trocar without having to force it in. The creation of the working space is greatly facilitated by using a combination of the laparoscope, gas insufflation, and the electrocautery scissors inserted through the posterior trocar.
A 5 mm laparoscope is introduced through this trocar at the end of the procedure during extraction of the operative specimen.

• Anterior trocar

1. Psoas major muscle
2. Musculofascial plane
3. Anterior trocar
The parietal peritoneum is retracted anteriorly with a fenestrated atraumatic grasper to allow for the insertion of the anterior operating trocar under visual control without rupturing the peritoneum.

7. Dissection of kidney

• Partial freeing

1. Parietal peritoneum
2. Working space
3. Inferior pole of left kidney
4. Left ureter
5. Psoas major muscle
6. Posterior dissection
Unlike in a total nephrectomy, the kidney should be mobilized as little as possible.
Its posterior surface is progressively dissected free from the perirenal fat. This step involves no particular technical difficulties.
The dissection begins on the posterior surface, and is pursued to the level of the poles.
During dissection of the superior border, the surgeon must remain in constant contact with the renal capsule to avoid getting lost in the adrenal fossa.Total mobilization of the kidney is not advisable. The kidney should remain attached by its anterior peritoneal attachments. This facilitates the exposure of the renal pedicle.

• Risks

1. Initial dissection of anterior surface of kidney
2. Peritoneal rupture
Initial dissection of the anterior surface of the kidney involves a risk of peritoneal rupture:
- if a very slight gas leak occurs, the surgeon can choose between a simple repair, achieved by fashioning a purse string with absorbable suture, or evacuating the leak with an intraperitoneal needle, which prevents the retroperitoneal space from caving in.
- if there is extensive rupture of the peritoneum, the surgeon must warn the anesthesiologist of the passage from a retroperitoneal approach to an intraperitoneal procedure, with the risk of rapid increase in the ETCO2 and ventilation pressures. Furthermore, the area of the rupture must be enlarged considerably to avoid being continually hindered by the peritoneal flap.
In our experience, rupture of the peritoneum has never led to the need for conversion.

8. Upper pole nephrectomy

• Upper pole of kidney

1. Dysplasic upper collecting system
2. Freeing of peritoneal attachments
The upper pole of the kidney is approached posteriorly, at its apex. It is progessively separated from the adrenal gland, and then freed from its peritoneal attachments. The dissection should be performed in contact with the renal capsule. The usual consistency of a dysplasic upper collecting system is quite soft, making it easy to grasp. If needed, a third operating trocar can be inserted. In case of major dilation of the upper collecting system that hinders the exposure, the surgeon should not hesitate to perform a percutaneous puncture of the renal pelvis.

• Division of the ureter

1. Ureter of upper collecting system
2. Renal pelvis of upper collecting system
The key to the mobilization of the upper pole of the kidney lies in the division of the ureter. After identifying both ureters, the ureter of the upper collecting system is divided as high as possible, against the renal pelvis. The cut section of the renal pelvis is then grasped with a fenestrated forceps, and the upper pole of the kidney is retracted to expose the upper pole vessels.

• Polar pedicles

1. Renal vessels
2. Superior pole pedicle
3. Dysplasic upper collecting system
4. Division of superior polar pedicle
The vascular pedicles of the upper and lower poles are identified. A clamping test can be performed with bulldog clamps introduced through one of the 5 mm operating trocars. In all cases, division of the polar vessels should not be considered until the vascular structures have been clearly identified. When precise identification is not possible, conversion to an open procedure is indicated. The superior polar pedicle can then be divided after using bipolar electrocautery or ultrasonic scalpel. A change in color of the renal parenchyma of the upper collecting system then appears rapidly, defining the limit of the parenchymal resection.

• Parenchymal resection

a. Towards lower pole of kidney
1. Opening of an infundibulum of a calyx
2. Second plane of resection
An ultrasonic scalpel is used to perform the parenchymal resection, posteriorly to anteriorly and laterally to medially, at the edge of the diseased area. If an infundibulum of a calyx is opened, it is important to check that it belongs to the upper pole before moving the plane of the parenchymal resection down toward the lower pole of the kidney (Jackman et al., 1998).

• Freeing of ureter

1. Division of ureter of upper collecting system
The ureter is freed caudally. Care must be taken not to damage the blood supply of the healthy portion of the ureter. The ureter is then divided as distal as possible after performing ligation with absorbable suture.

9. Extraction

The 10 mm laparoscope is replaced by a 5 mm laparoscope, which is introduced through the posterior trocar.
The retroperitoneal space is washed with lukewarm saline. Before extracting the operative specimen, a small caliber drain (eg, Redon CH8) can be placed through the anterior trocar.
We use a retrieval bag introduced through the trocar at the tip of the 12th rib.
The operative specimen, which is small in children, can usually be extracted without having to enlarge the initial incision.

10. Postop period

Food intake may be resumed on POD1.
The need for analgesics (continual administration of morphine IV during the first 12 hours, replaced by continual administration of nalbuphine IV, which is stopped at the patient’s request) is usually of short duration in children, rarely lasting more than 36 hours.
The drain and IV are usually removed on POD2.
The patient leaves the hospital on POD2 or POD3 and can resume normal activities 1 week following discharge.

Early postoperative complications:
- there is almost always a low fever for the first 48 postoperative hours, secondary to the cut surface of the parenchyma. Only symptomatic treatment is required;
- a urinoma can occur in the retroperitoneal space if the excretory cavities were opened. It is drained with a suction drain, but can lead to superinfection;
- a hematoma or wound infection is always possible.

The most serious complication is the loss of function of the remaining collecting system. This complication can be related to excessive intraoperative mobilization of the kidney, resulting in traction on the polar pedicle. We recommend checking for this complication 3 months after the operation by Doppler ultrasound of the kidney, and by DMSA renal scintigraphy if in doubt.

Published studies (Janetschek et al., 1997; Yao et al., 2000; Horowitz et al., 2001; El Ghoneimi et al., 1998; Peters, 2000; Shanberg et al., 2001) all underline the feasibility of partial nephrectomies by retroperitoneoscopy in children and infants, as well as a very low complication rate. This remains a technically challenging procedure, however, that requires extensive experience in retroperitoneoscopy.

11. Reference

Clayman RV, Kavoussi LR, Soper NJ, Dierks SM, Meretyk S, Darcy MD et al. Laparoscopic nephrectomy:
initial case report. J Urol 1991;146:278-82.
El-Ghoneimi A, Valla JS, Steyaert H, Aigrain Y. Laparoscopic renal surgery via a retroperitoneal approach
in children. J Urol 1998;160:1138-41.
Gaur DD. Retroperitoneal surgery of the kidney, ureter and adrenal gland. Endosc Surg Allied Technol
1995;3:3-8.
Gaur DD, Agarwal DK, Purohit KC. Retroperitoneal laparoscopic nephrectomy: initial case report. J Urol
1993;149:103-5.
Heloury Y. La laparoscopie en urologie pédiatrique. 979-985. In Abbou CC, Doublet JD, Gaston R,
Guillonneau B. La Laparoscopie en Urologie. Rapport du Congrès 1999 de l'Association Française
d'Urologie. Prog Urol 1999;9:841-1000.
Himpens J. Techniques, Equipment, and Exposure for Endoscopic Retroperitoneal Surgery. Semin
Laparosc Surg 1996;3:109-116.
Horowitz M, Shah SM, Ferzli G, Syad PI, Glassberg KI. Laparoscopic partial upper pole nephrectomy in
infants and children. BJU Int 2001;87:514-6.
Jackman SV, Cadeddu JA, Chen RN, Micali S, Bishoff JT, Lee BR et al. Utility of the harmonic scalpel for
laparoscopic partial nephrectomy. J Endourol 1998;12:441-4.
Janetschek G, Seibold J, Radmayr C, Bartsch G. Laparoscopic heminephroureterectomy in pediatric
patients. J Urol 1997;158:1928-30.
Peters CA. Laparoendoscopic renal surgery in children. J Endourol 2000;14:841-7; discussion 847-8.
Shanberg AM, Sanderson K, Rajpoot D, Duel B. Laparoscopic retroperitoneal renal and adrenal surgery in
children. BJU Int 2001;87:521-4.
Winfield HN, Donovan JF, Godet AS, Clayman RV. Laparoscopic partial nephrectomy: initial case report
for benign disease. J Endourol 1993;7:521-6.
Yao D, Poppas DP. A clinical series of laparoscopic nephrectomy, nephroureterectomy and
heminephroureterectomy in the pediatric population. J Urol 2000;163:1531-5.

Username
Password
	Remember me (needs cookies)