Division of Haematology/Oncology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
Br J Surg. 2011 Dec;98(12):1725-34. doi: 10.1002/bjs.7698. Epub 2011 Sep 27.
Predicting the long-term viability of ischaemic bowel during surgery is challenging. The aim was to determine whether intraoperative near-infrared angiography (NIR-AG) of ischaemic bowel might provide metrics that were predictive of long-term outcome.
NIR-AG using indocyanine green was performed on 24 pigs before, and after inducing bowel ischaemia to determine the feasibility of NIR-AG for detecting compromised perfusion. Contrast-to-background ratio (CBR) over time was measured in regions of interest throughout the bowel, and various metrics of the CBR-time curve were developed. Sixty rat small bowels, with or without strangulation, were imaged during surgery and on day 3 after operation. CBR metrics and clinical findings were assessed quantitatively for their ability to predict animal survival, histological grade of ischaemic injury and visible necrosis on day 3.
In ischaemic pig small bowel, various qualitative and quantitative CBR metrics appeared to correlate with bowel injury as a function of distance from normal bowel. In rats, intraoperative clinical assessment showed high specificity but low sensitivity for predicting outcome on day 3 after operation. Qualitative patterns of the CBR-time curve, such as absence of an arterial inflow peak and presence of a NIR filling defect, resulted in better prediction of survival (90 per cent), histological grade (85 per cent) and visible necrosis on day 3 (92 per cent).
Survival of ischaemic bowel was predicted by intraoperative NIR-AG with greater accuracy than clinical evaluation alone.
在手术中预测缺血性肠的长期存活能力具有挑战性。目的是确定术中近红外血管造影（NIR-AG）是否可以提供预测长期结果的指标。
在 24 头猪中进行了 NIR-AG 使用吲哚菁绿，以确定 NIR-AG 检测灌注受损的可行性。在整个肠道的感兴趣区域中测量时间上的对比背景比（CBR），并开发了 CBR 时间曲线的各种指标。在手术过程中以及手术后第 3 天对 60 只大鼠的小肠进行成像，有或没有绞窄。对 CBR 指标和临床发现进行定量评估，以预测动物的存活、第 3 天的缺血性损伤的组织学分级和可见坏死。
在缺血性猪小肠中，各种定性和定量 CBR 指标似乎与肠损伤相关，与正常肠的距离有关。在大鼠中，术中临床评估对术后第 3 天的结果具有高特异性但低敏感性。CBR 时间曲线的定性模式，如动脉流入峰的缺失和 NIR 充盈缺损的存在，导致对存活（90%）、组织学分级（85%）和第 3 天可见坏死（92%）的预测更好。
与单独临床评估相比，术中 NIR-AG 更准确地预测了缺血性肠的存活。
