Kulkarni R P, Bellamy E A
Department of Urology, Ashford Hospital, Ashford, UK.
BJU Int. 1999 May;83(7):755-9. doi: 10.1046/j.1464-410x.1999.00054.x.
To assess the ease on insertion, patient tolerance, undesirable side-effects, degree of encrustation and duration of upper tract decompression with a new thermo-expandable shape memory alloy ureteric stent.
From November 1996 to October 1998, 15 patients with ureteric strictures were treated with a new nickel-titanium shape-memory alloy stent, the Memokath 051 (Engineers & Doctors A/S, Hornbaek, Denmark). A total of 22 insertions were carried out. Ureteric obstruction was caused by recurrent colorectal carcinoma in four patients; two patients each with transitional cell carcinoma of the bladder, iatrogenic injury or ischaemia at the uretero-ileal anastomosis; and one patient each with metastatic lymph nodes from prostatic carcinoma, radiation-induced fibrosis, pelvi-ureteric junction obstruction, metastatic carcinoma of the vagina and extra-luminal endometriosis. The stent has a shaft diameter of 9 F and its proximal end expands to 17 F. The first three patients were treated with the original version, which expanded to 14 F. The unexpanded stent is inserted into the ureter after initial dilatation of the stricture to 12 F. The stent is expanded by injection with sterile water preheated to 50 degrees C. The procedures were carried out under a general anaesthetic and patients were allowed home the next day. The follow-up protocol included initial intravenous urography (IVU) at 6 weeks, with assessment of a mid-stream urine sample and renal function tests. These were repeated at 3-monthly intervals. Isotopic renography was performed when indicated.
The mean (range) follow-up was 10.6 (2-21) months; there was complete relief of upper tract obstruction in all patients. No stent-related symptoms, e.g. pain, sepsis, haematuria or frequency, were noted and no encrustation has occurred so far. The stent migrated in the first three patients with the original smaller diameter of stent but decompression of the upper tracts was maintained. None of the modified wider stents have migrated. The return of peristalsis in the proximal ureter was detected during IVU. There was no apparent endothelial growth through the stent material and no re-admissions for stent-related complications.
Early experience with this new stent is very encouraging. All patients have maintained satisfactory decompression of their upper tracts with no need for repeated hospitalization for stent changes. There have been no untoward side-effects so far. This stent appears to have a valuable place in the long-term management of ureteric strictures; it is probably most suited for malignant ureteric obstruction. It should be considered in the management of selected benign strictures that require long-term JJ stenting.
评估一种新型热膨胀形状记忆合金输尿管支架在插入的难易程度、患者耐受性、不良副作用、结痂程度以及上尿路减压持续时间等方面的情况。
1996年11月至1998年10月，15例输尿管狭窄患者接受了一种新型镍钛形状记忆合金支架（Memokath 051，丹麦霍恩拜克的工程师与医生有限公司）治疗。共进行了22次支架植入。4例患者输尿管梗阻由复发性结直肠癌引起；2例患者分别因膀胱移行细胞癌、医源性损伤或输尿管 - 回肠吻合口缺血所致；1例患者因前列腺癌转移性淋巴结、放射性纤维化、肾盂输尿管连接部梗阻、阴道转移性癌及腔外子宫内膜异位症。该支架杆部直径为9F，近端扩张至17F。前3例患者使用的是最初版本，近端扩张至14F。在将狭窄部位初步扩张至12F后，将未扩张的支架插入输尿管。通过注入预热至50摄氏度的无菌水使支架扩张。手术在全身麻醉下进行，患者次日即可回家。随访方案包括6周时的首次静脉肾盂造影（IVU），同时评估中段尿样本及肾功能测试。此后每3个月重复进行一次。必要时进行同位素肾图检查。
平均（范围）随访时间为10.6（2 - 21）个月；所有患者上尿路梗阻均完全缓解。未发现与支架相关的症状，如疼痛、脓毒症、血尿或尿频，且迄今为止未出现结痂。最初使用较小直径支架的前3例患者支架发生移位，但上尿路仍保持减压状态。改良后的较宽支架均未发生移位。IVU检查时发现近端输尿管蠕动恢复。未观察到内皮细胞通过支架材料生长，也没有因支架相关并发症再次入院的情况。
这种新型支架的早期经验非常令人鼓舞。所有患者上尿路均维持了满意的减压效果，无需因更换支架而反复住院。迄今为止未出现不良副作用。该支架在输尿管狭窄的长期治疗中似乎具有重要地位；可能最适用于恶性输尿管梗阻。对于需要长期放置双J支架的某些良性狭窄的治疗也应予以考虑。
