Step 5 Dissection and Ligation of the Renal Hilum

In comparison to the transperitoneal approach, the retroperitoneal approach allows the surgeon to achieve rapid and straightforward access to the renal hilum. The psoas is the most important early landmark to facilitate dissection.

Surgical orientation is achieved by orientating the psoas muscle in the horizontal plane, allowing the renal vessels to be orientated vertically.

After orienting the psoas muscle, the surgeon then looks for other surgical landmarks including: (i) the renal outline (easily appreciated), (ii) pulsations from the aorta or inferior vena cava, and (iii) the ureter (seen inferior to the kidney and medial to the psoas). Access to the renal hilum is initiated by dissecting in the fascial plane between the anteromedial aspect of the psoas muscle and posterior/inferior aspect of the kidney. The dissection is aided by the application of countertraction to the middle of the kidney with atraumatic laparoscopic forceps in the surgeon's nondominant hand. Dissection is accomplished with cautery or harmonic scalpel.

Dissection is performed one layer at a time, checking for the monophasic pulsations of the renal artery. The monophasic pulsations are in contradistinction to the biphasic pulsations seen from the inferior vena cava.

Once the artery is identified, it is mobilized by placing a right-angled instrument circumferentially around it. Branches of the renal artery are encountered if the dissection in the renal hilum occurs more distally. The artery is occluded with clips: three are placed on the aortic side and two on the kidney side, after which the artery is divided. The renal vein is identified anterior to the artery. Similarly, the vein is exposed with careful dissection until a right-angled instrument can be placed around it, giving enough exposure to accommodate an endo-GIA vascular stapler. The stapler is used to both occlude and ligate the vein (Fig. 7).

When performing a left-sided nephrectomy,the adrenal, gonadal,and lumber vein branches may also need to be clipped and divided.

■ When performing a right-sided nephrectomy, great care in the vein dissection is required to ensure that the vein dissected is the renal vein and not the inferior vena cava, which on occasion can have the appearance of the renal vein.

FIGURE 5 ■ Retroperitoneal working space is created with balloon dissection through the primary port site.
FIGURE 6 ■ The blunt port with internal fascial balloon and an external sponge cuff. The balloon and sponge cuff create an airtight seal, thus minimizing CO2 leakage and subcutaneous emphysema.

Dissection is initiated at the upper pole. The surgeon must then decide whether the adrenal will be spared or removed en bloc with the kidney. It is often easier to remove the left adrenal en bloc with the kidney because of the adrenal vein drainage into the already divided renal vein.

Separating the anterior aspect of Gerota's fascia from the peritoneum without creating a hole in the peritoneum requires care and meticulous dissection.

In some instances, particularly when the specimen is very large, entrapment is facilitated by creating an intentional anterior peritoneotomy. The specimen is then negotiated into the larger space of the peritoneal cavity, resulting in easier entrapment.

The surgeon is more likely to mistake the inferior vena cava for the renal vein if the dissection is too posterior.

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