Evaluation of cryoprobe deployment precision with body surface and in situ templates.
OBJECTIVE
To evaluate the precision of cryoprobe targeting with a surface template, an in situ template (on the target organ), or a combined approach.


METHODS
Fourteen participants placed five 17 G cryoprobes into porcine kidneys in a laparoscopic trainer using a surface template (group 1), an in situ template (group 2) or a combination of the two templates (group 3). The distance from the ideal probe placement was measured both on the anterior and posterior aspect of the kidney. The sequence of attempts was randomized. The distances were compared across the three groups using anova with the adjustment for multiple comparisons.


RESULTS
The mean distance from the ideal probe placement was 1.58 cm (anterior) and 1.81 cm (posterior) in group 1, 0.05 cm and 0.39 cm in group 2, and 0.07 cm and 0.22 cm in group 3, respectively. The placement of the probes was significantly more accurate in groups 2 (P < 0.001 anteriorly and P < 0.002 posteriorly) and 3 (P = 0.001 anteriorly and P < 0.001 posteriorly) compared with group 1. There was no significant difference between groups 2 and 3.


CONCLUSIONS
In this in vitro model, the use of internal or combined internal and external templates allows for significantly more precise deployment of 17-G cryoprobes than a standard external template alone.
Maxwell
Keegan L
KL
Division of Urology, Washington University school of Medicine, St. Louis, MO, USA.
Phillips
Courtney
C
Belani
Jay S
JS
Yan
Yan
Y
Landman
Jaime
J
D000704:Analysis of Variance; D000818:Animals; D003452:Cryosurgery / Q000379:methods / Q000592:standards*; D006801:Humans; D007680:Kidney Neoplasms / Q000601:surgery*; D013552:Swine