Twardowski Z J, Dobbie J W, Moore H L, Nichols W K, DeSpain J D, Anderson P C, Khanna R, Nolph K D, Loy T S
Department of Medicine, University of Missouri, Harry S. Truman Veterans Administration Hospital, Columbia.
Perit Dial Int. 1991;11(3):237-51.
There is scanty knowledge of the morphology of peritoneal dialysis catheter tunnels in humans, even though such knowledge may impact on peritoneal catheter design, implantation and postimplantation care. Past descriptions of catheter tunnels are based mainly on data from animal experiments. Based on these data, it has been assumed that epidermal spreading is inhibited by collagen fibers ingrown into the cuff. Our preliminary investigation indicated that this may not be the case in humans and led us to study catheter tunnel morphology in more detail. Eighteen catheter tunnels (2-5mm of tissue around the catheters) were removed in 17 peritoneal dialysis patients. The catheters were inserted 30 to 2013 days prior to removal (median 366 days). The catheters were removed electively or because of infectious or noninfectious complications. Contrary to the observations in animals, in only 1 case did epithelium extend to the cuff with only a minimal amount of granulation tissue present at the end of a 9 mm long sinus tract. In the remaining cases, the leading edge of the epithelium always met granulation tissue 1-14 mm from the exit, and the cuffs were found 8-33 mm from the exit. In tunnels older than 197 days, dense fibrous tissue was ingrown into the cuffs, and a dense fibrous capsule surrounded the cuff. The uninfected intercuff segment formed a pseudosheath, indistinguishable from a tendon sheath or synovial membrane. Infection in the catheter tunnel propagates through the part of the cuff adjacent to the tubing inside the capsule, suggesting that the cuff per se does not constitute a major barrier for spreading infection. This observation, by exclusion, infers that the beneficial role of an external cuff in decreasing exit infections is by providing firm anchorage of the catheter resulting in restriction of its piston like movement and thereby minimizing trauma and inward conveyance of outer sinus tract flora.
尽管有关腹膜透析导管隧道的形态学知识可能会影响腹膜导管的设计、植入及植入后的护理，但目前人们对人体腹膜透析导管隧道的形态学了解甚少。过去对导管隧道的描述主要基于动物实验数据。基于这些数据，人们认为长入袖套的胶原纤维会抑制表皮蔓延。我们的初步研究表明，人类的情况可能并非如此，这促使我们更详细地研究导管隧道的形态。我们从17名腹膜透析患者身上移除了18个导管隧道（导管周围2 - 5毫米的组织）。这些导管在移除前已插入30至2013天（中位数为366天）。导管是选择性移除的，或是因感染性或非感染性并发症而移除。与动物实验的观察结果相反，只有1例上皮细胞延伸至袖套，在一条9毫米长的窦道末端仅有少量肉芽组织。在其余病例中，上皮细胞的前缘总是在距出口1 - 14毫米处与肉芽组织相遇，袖套位于距出口8 - 33毫米处。在超过197天的隧道中，致密的纤维组织长入袖套，袖套周围形成致密的纤维囊。未感染的袖套间段形成一个假鞘，与腱鞘或滑膜难以区分。导管隧道内的感染通过囊内与导管相邻的袖套部分传播，这表明袖套本身并非感染传播的主要屏障。通过排除法，这一观察结果推断出外部袖套在减少出口感染方面的有益作用是通过为导管提供牢固的固定，从而限制其类似活塞的运动，进而将外窦道菌群的创伤和向内传播降至最低。
