Rapid sealing and cutting of porcine blood vessels,ex vivo, using a high-power, 1470-nm diode laser

Abstract

Abstract. Suture ligation with subsequent cutting of blood vessels to maintain hemostasis during surgery is time consuming and skill intensive. Energy-based electrosurgical and ultrasonic devices are often used to replace sutures and mechanical clips to provide rapid hemostasis and decrease surgery time. Some of these devices may create undesirably large collateral zones of thermal damage and tissue necrosis, or require separate mechanical blades for cutting. Infrared lasers are currently being explored as alternative energy sources for vessel sealing applications. In a previous study, a 1470-nm laser was used to seal vessels 1 to 6 mm in diameter in 5 s, yielding burst pressures of ∼500 mmHg. The purpose of this study was to provide vessel sealing times comparable with current energy-based devices, incorporate transection of sealed vessels, and demonstrate high vessel burst pressures to provide a safety margin for future clinical use. A 110-W, 1470-nm laser beam was transmitted through a fiber and beam shaping optics, producing a 90-W linear beam 3.0 by 9.5 mm for sealing (400 W∕cm 2 ), and 1.1 by 9.6 mm for cutting (1080 W∕cm 2 ). A two-step process sealed and then transected ex vivo porcine renal vessels (1.5 to 8.5 mm diameter) in a bench top setup. Seal and cut times were 1.0 s each. A burst pressure system measured seal strength, and histologic measurements of lateral thermal spread were also recorded. All blood vessels tested (n ¼ 55 seal samples) were sealed and cut, with total irradiation times of 2.0 s and mean burst pressures of 1305 AE 783 mmHg. Additional unburst vessels were processed for histological analysis, showing a lateral thermal spread of 0.94 AE 0.48 mm (n ¼ 14 seal samples). This study demonstrated that an optical-based system is capable of precisely sealing and cutting a wide range of porcine renal vessel sizes and, with further development, may provide an alternative to radiofrequency-and ultrasonic-based vessel sealing devices.

Doppler optical coherence tomography for energy seal evaluation and comparison to visual evaluation

“…Given this, it is paramount to have an objective method with which vessel seals can be evaluated so that the hemostatic capabilities of laser-based systems can be tested. Current methodologies used for this purpose include burst pressure analysis (BPA), [9][10][11] microscopy, 12 and visual examination. [13][14][15][16] While BPA yields valuable insight as to the strength of seals, it cannot be performed in situ without invasive measures.…”

Infrared laser sealing of porcine vascular tissues using a 1,470 nm diode laser: Preliminary in vivo studies

“…The 1,470 nm wavelength was found to seal porcine vessels of 1–6 mm diameter in less than 5 seconds. A subsequent study demonstrated faster sealing, transection of sealed tissue, increased burst strength, and greater safety margin . The laser sealed and cut ex vivo porcine renal arteries of 1–8 mm diameter in 2 seconds, yielding burst pressures greater than 1,200 mmHg and thermal coagulation zones less than 3 mm.…”

Rapid sealing of porcine renal blood vessels, ex vivo, using a high power, 1470-nm laser, and laparoscopic prototype

“…Our laboratory is currently exploring infrared (IR) lasers as an alternative energy modality for vessel sealing, capable of generating less collateral thermal damage. 21,22 Previous studies demonstrated the feasibility of sealing vessels in an open in vivo porcine model using a 1470-nm diode laser. 23 However, the initial prototype was designed for testing in open surgery and featured a plunger style tissue clasping mechanism and 12.7-mm outer-diameter optical components in the light delivery mechanism that were incompatible with standard laparoscopic surgical instruments and size constraints.…”

“…Fresh porcine kidney pairs were obtained from a slaughterhouse (Spear Products, Inc., Coopersburg, Pennsylvania) and renal arteries were then dissected, cleaned of fat, and kept hydrated with saline for use within 24 h. The entire vascular tree for each kidney was carefully dissected and surgically exposed in a similar manner to previous studies, 21,22 providing multiple vessels with a wide range of diameters for testing. A total of 69 vessels were tested, ranging from 1.0 to 6.6 mm in diameter and with a mean diameter of 3.3 AE 1.7 mm.…”