Prospective evaluation of the effect of adherent perinephric fat on outcomes of robotic assisted partial nephrectomy following elimination of the learning curve

ABSTRACT Purpose: To prospectively evaluate the association of adherent perinephric fat (APF) on perioperative outcomes of robotic-assisted partial nephrectomy (RAPN) following elimination of the surgical learning curve. Materials and Methods: 305 consecutive RAPNs performed by a single experienced surgeon were analyzed. The first 100 RAPNs were considered the learning curve and therefore excluded. APF was defined as the necessity of subcapsular renal dissection to mobilize the tumor from surrounding perinephric fat. Perioperative outcomes were evaluated including operative time, warm ischemia time (WIT), postoperative complications, length of stay, margins, ischemia, and complications score (MIC), estimated blood loss (EBL), and change in pre-operative to postoperative day 1 (POD 1) laboratory values. After correction for multiple comparisons, P values ≤0.0045 were considered statistically significant but associations with P values ≤0.05 were also mentioned in the study results. Results: Fifty-eight (28.3%) patients had APF. Patients with APF had longer operative times compared to those without APF (median, 213 vs. 192 minutes, P <0.001). There was some evidence of higher increase in change in creatinine from preoperative to POD 1 among those with APF compared to those without APF, although this was not statistically significant (median, 0.2 vs. 0.1mg/dL, P=0.03). There were no other statistically significant associations between presence of APF and perioperative outcomes. Conclusions: APF is associated with increased operative time but no change in other perioperative outcomes. Surgeon experience does not affect perioperative outcomes associated with APF.

摘要
研究目的：前瞻性评估在消除手术学习曲线影响后，粘连性肾周脂肪（adherent perinephric fat, APF）与机器人辅助部分肾切除术（robotic-assisted partial nephrectomy, RAPN）围手术期结局的关联。

材料与方法：分析由单一位经验丰富术者实施的305例连续纳入的机器人辅助部分肾切除术病例。前100例手术视为手术学习曲线阶段病例，故予以排除。粘连性肾周脂肪被定义为需进行肾包膜下分离以将肿瘤从周围肾周脂肪中游离出来的情况。本研究评估的围手术期结局包括手术时长、热缺血时间（warm ischemia time, WIT）、术后并发症、住院时长、切缘情况、缺血状态、并发症评分（complications score, MIC）、估计失血量（estimated blood loss, EBL）以及术前至术后第1天（postoperative day 1, POD 1）的实验室检验指标变化。经多重比较校正后，P值≤0.0045被认为具有统计学意义，但本研究结果中也提及了P值≤0.05的关联。

结果：58例（28.3%）患者存在粘连性肾周脂肪。与无粘连性肾周脂肪的患者相比，粘连性肾周脂肪患者的手术时长更长（中位时长：213 min vs 192 min，P<0.001）。尽管未达到经多重比较校正后的统计学显著性阈值（P≤0.0045），但与无粘连性肾周脂肪的患者相比，粘连性肾周脂肪患者术前至术后第1天的肌酐变化增幅更高（中位增幅：0.2mg/dL vs 0.1mg/dL，P=0.03）。粘连性肾周脂肪的存在与其余围手术期结局均未发现具有统计学意义的关联。

结论：粘连性肾周脂肪与手术时长增加相关，但与其他围手术期结局无显著关联。术者经验并不会影响与粘连性肾周脂肪相关的围手术期结局。