East Jeffrey M
Department of Surgery, Cornwall Regional Hospital (CRH), Montego Bay, Jamaica.
BMC Res Notes. 2013 Feb 4;6:48. doi: 10.1186/1756-0500-6-48.
Colonoscopes are designed with balance between flexibility, required to negotiate angulations, and stiffness, required to counteract the propensity for looping in unfixed sections of the colon, which retards advancement of the instrument. Colonoscopy can be challenging with old instruments that have lost native stiffness and become less responsive to torquing.A new intraluminal stiffening device has become available in two grades of stiffness. However, there is no published evidence of its effectiveness. This randomized, controlled trial was designed to determine the effectiveness of the stiffening wires in improving cecal intubation rate and time following routine application. A secondary analysis determines effectiveness of application only after intractable failure with the unaided colonoscope.
The colonoscope tested was an Olympus CF-100TL, approximately fifteen years old. Patients were randomly assigned to the unaided colonoscope or the standard or firm wire introduced routinely on entry into transverse colon. Each phase of colonoscopy was timed. Failure to advance the colonoscope for 5 minutes (despite usual manipulations to minimize looping) required switching to another intervention according to a prescribed methodology and the originally assigned intervention was recorded as failed.
The study was terminated after accrual of 112 participants (target sample size 480) because the colonoscope required repairs (no damage attributable to stiffening wires) which would have been uneconomical. There were no statistically significant differences between per-protocol cecal intubation rates (81.1, 71.1 and 70.3 percent respectively), a finding which persisted after multiple imputation for a virtual sample size of 480. Similarly, there were no statistically significant differences between per-protocol cecal intubation times (15, 16.2 and 13.9 minutes). However, a statistically significant improvement in cecal intubation rate (from 81.1% to 97.3%, P = 0.0313) was achieved when the wires were applied after intractable failure of the unaided colonoscope in the first intervention group.
Routine application of either stiffening wire does not improve caecal intubation rate nor time compared to the unaided colonoscope. However, application of the stiffening wires after intractable failure of the unaided colonoscope enabled a statistically significant improvement in cecal intubation rate.
clinicaltrials.gov Identifier: NCT01115010.
结肠镜的设计需在柔韧性和硬度之间取得平衡。柔韧性是通过结肠弯曲部位所必需的，而硬度则是用来抵消结肠非固定段出现成袢倾向所必需的，这种成袢倾向会阻碍器械前进。对于已丧失固有硬度且对扭转操作反应性降低的旧器械，结肠镜检查可能具有挑战性。一种新型腔内硬化装置有两种硬度等级可供使用。然而，尚无已发表的关于其有效性的证据。本随机对照试验旨在确定硬化钢丝在常规应用后提高盲肠插管率和缩短时间方面的有效性。二次分析仅在使用未辅助结肠镜检查出现顽固性失败后确定应用的有效性。
所测试的结肠镜是一台约有15年历史的奥林巴斯CF - 100TL。患者被随机分配至未辅助结肠镜组，或在进入横结肠时常规插入标准钢丝或硬质钢丝组。结肠镜检查的每个阶段都进行计时。若结肠镜在5分钟内无法推进（尽管采取了常规操作以尽量减少成袢），则需根据规定方法改用另一种干预措施，并将最初分配的干预措施记录为失败。
在招募了112名参与者（目标样本量480）后，该研究终止，因为结肠镜需要维修（无因硬化钢丝导致的损坏），而维修成本过高。符合方案的盲肠插管率（分别为81.1%、71.1%和70.3%）之间无统计学显著差异，在对虚拟样本量480进行多次插补后，这一结果依然存在。同样，符合方案的盲肠插管时间（15、16.2和13.9分钟）之间也无统计学显著差异。然而，在第一个干预组中，在未辅助结肠镜检查出现顽固性失败后应用钢丝时，盲肠插管率有统计学显著提高（从81.1%提高到97.3%，P = 0.0313）。
与未辅助的结肠镜相比，常规应用任何一种硬化钢丝均未提高盲肠插管率和缩短插管时间。然而，在未辅助结肠镜检查出现顽固性失败后应用硬化钢丝可使盲肠插管率有统计学显著提高。
clinicaltrials.gov标识符：NCT01115010。
