Rabi Yaron, Katzir Abraham
School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978, Israel.
Lasers Surg Med. 2010 Jul;42(5):425-32. doi: 10.1002/lsm.20927.
Bonding of tissues by laser heating is considered as a future alternative to sutures and staples. Increasing the post-operative bond strength remains a challenging issue for laser tissue bonding, especially in organs that have to sustain considerable tension or pressure. In this study, we investigated the influence of different temporal heating profiles on the strength of soldered incisions. The thermal damage following each heating procedure was quantified, in order to assess the effect of each heating profile on the thermal damage.
Incisions in porcine bowel tissue strips (1 cmx4 cm) were soldered, using a 44% liquid albumin mixed with indocyanine green and a temperature controlled laser (830 nm) tissue bonding system. Heating was done either with a linear or a step temporal heating profile. The incisions were bonded by soldering at three points, separated by 2 mm. Set-point temperatures of T(set) = 60, 70, 80, 90, 100, 110, 150 degrees C and dwell times of t(d) = 10, 20, 30, 40 seconds were investigated. The bond strength was measured immediately following each soldering by applying a gradually increased tension on the tissue edges until the bond break.
Bonds formed by linear heating were stronger than the ones formed by step heating: at T(set) = 80 degrees C the bonds were 40% stronger and at T(set) = 90 degrees C the bonds strength was nearly doubled. The bond strength difference between the heating methods was larger as T(set) increased.
Linear heating produced stronger bonds than step heating. The difference in the bond strength was more pronounced at high set-point temperatures and short dwell times. The bond strength could be increased with either higher set-point temperature or a longer dwell time.
通过激光加热实现组织黏合被视为缝合和钉合的一种未来替代方法。提高术后黏合强度对于激光组织黏合来说仍然是一个具有挑战性的问题，尤其是在必须承受相当大张力或压力的器官中。在本研究中，我们调查了不同时间加热曲线对焊接切口强度的影响。对每个加热程序后的热损伤进行了量化，以评估每种加热曲线对热损伤的影响。
使用与吲哚菁绿混合的44%液体白蛋白和温度控制的激光（830nm）组织黏合系统对猪肠组织条（1cm×4cm）上的切口进行焊接。加热采用线性或阶梯式时间加热曲线。切口在三个点进行焊接，点与点之间相隔2mm。研究了设定温度T(set)=60、70、80、90、100、110、150℃以及停留时间t(d)=10、20、30、40秒的情况。每次焊接后，通过在组织边缘逐渐增加张力直至黏合处断裂，立即测量黏合强度。
线性加热形成的黏合比阶梯式加热形成的黏合更强：在T(set)=80℃时，黏合强度高40%，在T(set)=90℃时，黏合强度几乎翻倍。随着T(set)升高，加热方法之间的黏合强度差异更大。
线性加热产生的黏合比阶梯式加热更强。在高设定温度和短停留时间下，黏合强度差异更为明显。黏合强度可通过更高的设定温度或更长的停留时间来提高。
