Experimental Data

The porcine model was used by Pompeo et al. to describe transthoracic (TT) left adrenalectomy in 1997 (13). After inserting four 10-mm laparoscopic trocars into the left pleural cavity, left pneumothorax was created insufflating CO2 at a mean pressure of 10 mmHg. A 6-cm phrenotomy was performed starting from the lateral side of the aorta and retroperitoneal space entry was achieved. Carbon dioxide-induced positive intrapleural pressure facilitated this maneuver. After Gerota's fascia opening and gentle spleen retraction, the adrenal gland was identified and dissected downward. Endoscopic clips were used to control small tributary vessels, which were subsequently divided. Blunt dissection was used to free the inferior pole of the adrenal gland from the renal vein until the main adrenal vein was identified, clipped, and divided. The specimen was retrieved through one of the trocars. Adequate hemostasis was secured and phrenotomy repaired with running nonabsorbable suture placed with endosuture technique. Laparoscopic exit was performed after reexpansion of the ipsi-lateral lung. Mean operative time was 2.75 hours, mean blood loss was 76 cc. Complications included splenic injury in one pig and difficult diaphragmatic repair in another. However, all the procedures (n = 5) were successfully completed. Endoscopic suturing or staples were used to perform thoracoscopic repair of the diaphragmatic incision (13,14).

In 2000, Meraney et al. performed the first thoracoscopic transdiaphragmatic bilateral nephrectomy in an acute porcine model (15). In their study, three ports were used to gain thoracic access and the retroperitoneum was accessed through a diaphragmatic incision. Feasibility of individual control of the renal artery and vein, and circumferential mobilization of the kidney was assessed. Acceptable intraoperative arterial blood gas parameters were maintained in all procedures. The spleen during left-sided nephrectomy, and the liver during right-sided nephrectomy, respectively, were adequately retracted using a TT 10 mm fan retractor. Mean diaphragmatic incision was 7.2 cm. Diaphragm repair was performed placing continuous sutures. Perioperative results showed mean surgical time of 69.3 minutes for left nephrectomy (n = 4) and 74.3 minutes for right nephrectomy (n = 4), and a mean blood loss of 18.7 cc.

Based on the encouraging results of the porcine study (10), Gill et al. developed and refined the technique for thoracoscopic nephrectomy and extrapolated the approach to adrenal surgery in human cadavers (16). Four human cadavers underwent bilateral thoracoscopic transdiaphragmatic nephrectomy (Table 1).

After access and development of the retroperitoneal space, individual control of the renal artery and vein was feasible in all eight procedures. However, the necessary exposure was achieved only after performing considerable TT retraction of the liver or spleen despite the lateral position in which all the cadavers were placed. Left nephrectomy and right nephrectomy required a mean surgical time of 64.3 minutes and of 82.5 minutes,

TABLE 1 ■ Thoracoscopic Transdiaphragmatic Nephrectomy: Human Cadaver Study

Variables

Left nephrectomy (range)

Right nephrectomy (range)

No. subjects

4

4

Mean surgical time (min)

64.3 (54-76 )

82.5 (72-90 )

Individual steps (min):

Diaphragmatic incision

11(10-13 )

11.5 (10-13 )

Hilar dissection

26.2 (24-31 )

31 (29-36 )

Renal vessel control

10.2 (9-11 )

13 (11-15 )

Diaphragmatic repair

19.2 (16-23 )

22.2 (20-25 )

Diaphragmatic incision length (cm)

10(8-12 )

9.5 (8-12 )

No. inadvertent celiotomy

1

1

Ureteral length (cm)

5.6 (3.5-8 )

3.9 (3-4.5 )

Source: From Ref. 16.

respectively. Approximately half an hour was necessary to perform hilar dissection on either side, with no injury occurring to the renal vessels. Specimen mobilization resulted in inadvertent peritoneotomy in two instances. However, intraoperative exposure was not compromised by such events. No inadvertent injury to adjacent organs occurred. Suture repair of a mean diaphragmatic incision of 10 cm could be performed adequately.

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