Efeitos do laser KTP na dissecção laparoscópica do feixe neuro-vascular cavernoso em modelo experimental canino / Effect of KTP laser in the laparoscopic dissection of the cavernous neurovascular bundles

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Introduction: Electrical and ultrasonic energy used in nerve-sparing laparoscopic radical prostatectomy can compromise cavernous nerve function. Laser energy may potentially allow fine dissection with good hemostasis and minimal adjacent tissue injury. This study examines the electrophysiological, histological and thermal mapping features of KTP laser dissection on cavernous nerve function in the survival canine model. Materials and Methods: A total of 36 dogs were divided into 3 groups. Laparoscopic unilateral neurovascular bundle (NVB) mobilization was performed using either: (1) KTP laser (n=12), (2) ultrasonic shears (US) (n=12), or (3) athermally with cold scissors (AT) (n=12). The contralateral NVB remained undissected as an internal control. NVB function was assessed acutely in all dogs, and after 1-month survival in 50% of the dogs of each group. Peak intracavernosal pressure response to cavernous nerve stimulation was measured as a percentage of mean arterial pressure (ICP/MAP). Strips of peritoneum were sectioned ex-vivo with the KTP laser and US shears for thermographic mapping. Histological evaluation of prostatic fascia necrosis from the cutting surface was also performed. Results: Comparing KTP and AT groups, the erectile response to nerve stimulation was similar acutely and at 1 month (acute ICP/MAP: KTP 92%, AT 96% p=0.54; chronic ICP/MAP: KTP 95%, AT 98% p=0.71). In contrast, US dissection resulted in a significant decrease in the ICP response compared to the KTP and AT groups (acute ICP/MAP: US 49%, KTP 92%, AT 96%. US vs. KTP p<0.001, US vs. AT p<0.001; chronic ICP/MAP: US 58%, KTP 95%, AT 98%, US vs. KTP p=0.02, US vs. AT p=0.02). Mean NVB dissection times were similar (KTP 27.5min, US 19.9min, AT 26.6min, KTP vs. US p=0.21, KTP vs. AT p=0.81, US vs. AT p=0.22). Histopathology demonstrated an acute zone of laser-induced necrosis of approximately 500 um compared to 2 mm with US dissection. Thermographic assessment demonstrated significantly less collateral thermal spread from the KTP laser compared to US (mean thermal spread >60 oC KTP 0.98 mm vs. US 6.25 mm, p<0.0001). Conclusions: Use of KTP laser for NVB mobilization preserved cavernous nerve function comparable to standard athermal techniques using cold scissors and was superior to ultrasonic shears.

ASSUNTO(S)

outcome assessment (health care) laser lasers models animals análise de resultados (cuidados de saúde) laparoscopy modelos animais laparoscopia

ACESSO AO ARTIGO

Documentos Relacionados