Buckmire M, Parquet G, Seeburger J L, Fukuchi S G, Rolandelli R H
Allegheny University of the Health Sciences and the Philadelphia Veterans Administration Medical Center, Pennsylvania, USA.
Dis Colon Rectum. 1998 Oct;41(10):1273-80. doi: 10.1007/BF02258228.
Dehiscence of colonic anastomoses is prevalent and potentially fatal. In an attempt to reduce the likelihood of anastomotic dehiscence, the colon is cleansed before surgery and fiber-free diets are prescribed postoperatively. However, fiber-free diets induce colonic atrophy and impair healing. This study was designed to investigate the effect of bowel preparation and postoperative fiber-free diet on the local gene expression of transforming growth factor-beta 1 and procollagen type I.
Four Sprague-Dawley rats underwent bowel preparation with a fiber-free liquid diet and polyethylene glycol in a balanced electrolyte solution for two days (fiber-free preoperative diet group), whereas four rats received standard chow with fiber (preoperative diet with fiber group). On the third day tissue was obtained from the descending colon of each rat to assess the effect of bowel preparation. Forty additional rats had their bowels prepared and underwent transection of the descending colon and anastomosis. These rats were then randomly assigned to continue on the liquid diet (fiber-free postoperative diet group) or rat chow (postoperative diet with fiber group). On postoperative days 3, 5, 6, 7, and 14, colonic tissue was obtained from the anastomosis and analyzed with the use of semiquantitative reverse transcriptase-polymerase chain reaction to examine the relative expression of transforming growth factor-beta 1 and procollagen type I genes normalized to that of a constitutive gene.
There was a decrease in the expression of the transforming growth factor-beta 1 and the procollagen type I genes in the fiber-free preoperative diet group compared with the preoperative diet with fiber group; however, this difference only reached statistical significance for procollagen type I. Postoperatively, significant increases in the expression of the transforming growth factor-beta 1 and procollagen type I genes over baseline levels were observed around postoperative day 7 in both groups, which temporally correlates with active phases of collagen deposition in the wounded colon. Expression of the procollagen type I gene, however, was significantly decreased at this time in the fiber-free postoperative diet group compared with the postoperative diet with fiber group.
Although necessary to reduce septic complications, preoperative bowel preparation has a detrimental effect on the expression of transforming growth factor-beta 1 and procollagen type I. A postoperative fiber-free liquid diet also may be detrimental to the expression of these transcripts in the bowel. Alternative methods for delivery of colonic fuels are needed to create a better environment for colonic healing while eliminating bacteria and bulk.
结肠吻合口裂开很常见且可能致命。为降低吻合口裂开的可能性，术前会对结肠进行清洁，并在术后规定无纤维饮食。然而，无纤维饮食会导致结肠萎缩并损害愈合。本研究旨在调查肠道准备和术后无纤维饮食对转化生长因子-β1和I型前胶原局部基因表达的影响。
4只Sprague-Dawley大鼠采用无纤维流食和聚乙二醇平衡电解质溶液进行肠道准备2天（术前无纤维饮食组），而4只大鼠接受含纤维的标准饲料（术前含纤维饮食组）。在第3天从每只大鼠的降结肠获取组织，以评估肠道准备的效果。另外40只大鼠进行肠道准备，然后横断降结肠并进行吻合。这些大鼠随后被随机分配继续食用流食（术后无纤维饮食组）或大鼠饲料（术后含纤维饮食组）。在术后第3、5、6、7和14天，从吻合口获取结肠组织，并用半定量逆转录聚合酶链反应进行分析，以检测转化生长因子-β1和I型前胶原基因相对于组成型基因的相对表达。
与术前含纤维饮食组相比，术前无纤维饮食组中转化生长因子-β1和I型前胶原基因的表达降低；然而，这种差异仅在I型前胶原方面达到统计学意义。术后，两组在术后第7天左右均观察到转化生长因子-β1和I型前胶原基因表达比基线水平显著增加，这在时间上与受伤结肠中胶原沉积的活跃阶段相关。然而，此时术后无纤维饮食组中I型前胶原基因的表达与术后含纤维饮食组相比显著降低。
尽管术前肠道准备对于减少感染并发症是必要的，但它对转化生长因子-β1和I型前胶原的表达有不利影响。术后无纤维流食也可能对肠道中这些转录本的表达不利。需要替代的结肠营养输送方法，以在消除细菌和食物残渣的同时为结肠愈合创造更好的环境。
