nitinol and Colorectal-Neoplasms

Clinically, colorectal stents can only palliatively relieve obstruction caused by colorectal cancer (CRC), with a high incidence of stent migration and tumor-related re-obstruction. To overcome these shortcomings, we developed a colorectal stent composed of a structure-optimized nitinol braided stent and a tubular film including an inner layer of poly (ethylene-co-vinyl acetate) (EVA) and a segmental outer layer of EVA with paclitaxel (PTX). The braiding pattern, segment number, and end shape of the stent were optimized based on the mechanical properties, ex vivo and in vivo anti-migration performance, and tissue response of the stent. The optimized nitinol stent had a structure of one middle segment in a hook-pattern and two end segments in a cross-pattern with two studs on each end in a staggered arrangement. Structure-optimized colorectal stents were prepared and evaluated in vivo. PTX released from the stent was mostly distributed in the rabbit rectum in contact with it. The biosafety of the colorectal stent was evaluated using blood tests, biochemical analysis, anatomical observation, and pathological analysis. The anti-tumor effect of the stent was also evaluated by endoscopy, anatomical observation, and pathological and immunohistochemical analyses in rabbits with orthotopic CRC. The results demonstrate that the optimized colorectal stents have effective anti-migration ability and anti-tumor effects with good biosafety. STATEMENT OF SIGNIFICANCE: In order to overcome the most common disadvantages of migration and re-obstruction of colorectal stents clinically, a colorectal stent composed of a structure-optimized nitinol stent and a tubular film including an inner layer of EVA and a segmental outer layer of EVA with PTX was put forward in this study. The optimized nitinol stent had a structure of one middle segment in hook-pattern and two end segments in cross-pattern with two studs on each end in staggered arrangement. The resulting colorectal stent has been proved with good anti-migration ability, anti-tumor effects, and biosafety in vivo, which provides a safe and effective potential treatment modality for patients with colorectal cancer.

Topics: Alloys; Animals; Colorectal Neoplasms; Paclitaxel; Rabbits; Stents

Compared to emergency surgery, self-expandable metallic stents are effective and safe when used as bridge-to-surgery (BTS) in operable patients with acute colorectal cancer obstruction. In this study, we report data on the new conformable colonic stents.. To evaluate clinical effectiveness of conformable stents as BTS in patients with acute colorectal cancer obstruction.. This was a retrospective study.. The study was conducted at six Italian Endoscopic Units.. Data about patients with acute malignant colorectal obstruction were collected between 2007 and 2012.. All patients were treated with conformable stents as BTS. Technical success, clinical success, rate of primary anastomosis and colostomy, early and late complications were evaluated.. Data about 88 patients (62 males) were reviewed in this study. Conformable SEMS were correctly deployed in 86 out of 88 patients, with resolution of obstruction in all treated patients. Tumor resection with primary anastomosis was possible in all patients. A temporary colostomy was performed in 40. Early complications did not occur. Late complications occurred in 11 patients. Stent migration was significantly higher in patients treated with partially-covered stents compared to the uncovered group (35% vs. 0%, P<0.001). Endoscopical re-intervention was required in 12% of patients. One patient with rectal cancer had an anastomotic dehiscence after surgery and he was successfully treated with endoscopic clipping. One year after surgery, all patients were alive and local recurrence have not been documented.. This was a retrospective and uncontrolled study.. Preliminary data from this large case series are encouraging, with a high rate of technical and clinical success and low rate of clinically relevant complications. Partially-covered SEMS should be avoided in order to reduce the risk of endoscopic re-intervention.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Coated Materials, Biocompatible; Colorectal Neoplasms; Endoscopy, Digestive System; Female; Humans; Intestinal Obstruction; Male; Middle Aged; Polytetrafluoroethylene; Retrospective Studies; Self Expandable Metallic Stents

This study aimed to evaluate the safety and efficacy of a new nickel-titanium shape memory alloy compression anastomosis ring, NiTi CAR 27, in constructing an anastomosis for colorectal cancer resection compared with conventional staples.. In total, 234 consecutive patients diagnosed with colorectal cancer receiving sigmoidectomy and anterior resection for end-to-end anastomosis from May 2010 to June 2012 were retrospectively analyzed. The postoperative clinical parameters, postoperative complications and 3-year overall survival in 77 patients using a NiTi CAR 27 compression ring (CAR group) and 157 patients with conventional circular staplers (STA group) were compared.. There were no statistically significant differences between the patients in the two groups in terms of general demographics and tumor features. A clinically apparent anastomotic leak occurred in 2 patients (2.6%) in the CAR group and in 5 patients (3.2%) in the STA group (p=0.804). These eight patients received a temporary diverting ileostomy. One patient (1.3%) in the CAR group was diagnosed with anastomotic stricture through an electronic colonoscopy after 3 months postoperatively. The incidence of postoperative intestinal obstruction was comparable between the two groups (p=0.192). With a median follow-up duration of 39.6 months, the 3-year overall survival rate was 83.1% in the CAR group and 89.0% in the STA group (p=0.152).. NiTi CAR 27 is safe and effective for colorectal end-to-end anastomosis. Its use is equivalent to that of the conventional circular staplers. This study suggests that NiTi CAR 27 may be a beneficial alternative in colorectal anastomosis in Chinese colorectal cancer patients.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Anastomosis, Surgical; Anastomotic Leak; Colon, Sigmoid; Colorectal Neoplasms; Equipment Design; Equipment Safety; Female; Humans; Male; Middle Aged; Postoperative Period; Retrospective Studies; Surgical Staplers; Treatment Outcome; Young Adult

Endoscopic colonic stenting with self-expanding metallic stents is now widely used to treat malignant large bowel obstruction, where temporary or permanent decompression of the large bowel is desired. The medical records of patients who underwent endoscopic colonic stenting for malignant large bowel obstruction between May 2004 and May 2011 were reviewed. Success rate, morbidity, and mortality rate along with patient characteristics were documented. Sixty-seven patients were included. The procedure was used as a bridge to surgery in 38 and as a palliative measure in 29. Success rate was 95.5 per cent. Perforation and reobstruction occurred in three and three patients, respectively. All of the patients who developed perforation or reobstruction underwent emergency surgery. Endoscopic stenting offers a safe and effective treatment option in patients with malignant large bowel obstruction with comparable outcomes.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Colorectal Neoplasms; Decompression, Surgical; Endoscopy; Female; Humans; Intestinal Obstruction; Male; Middle Aged; Prosthesis Design; Retrospective Studies; Stents; Treatment Outcome

A 12-year-old castrated male Labrador Retriever was evaluated for clinical signs associated with colorectal obstruction.. The dog had a 2-week history of tenesmus and hematochezia. On rectal examination, an annular colorectal mass was palpable extending orad into the pelvic canal. The original diagnosis of the colorectal mass was a mucosal adenoma. The dog was maintained on a low-residue diet and fecal softeners for a period of 13 months after initial diagnosis. At that time, medical management was no longer effective.. Placement of a colonic stent was chosen to palliate the clinical signs associated with colorectal obstruction. By use of fluoroscopic and colonoscopic guidance, a nitinol stent was placed intraluminally to open the obstructed region. Placement of the stent resulted in improvement of clinical signs, although tenesmus and obstipation occurred periodically after stent placement. At 212 days after stent placement, the patient had extensive improvement in clinical signs with minimal complications; however, clinical signs became severe at 238 days after stent placement, and the dog was euthanized. Histologic evaluation of the rectal tumor from samples obtained during necropsy revealed that the tumor had undergone malignant transformation to a carcinoma in situ.. A stent was successfully placed in the colon and rectum to relieve obstruction associated with a tumor originally diagnosed as a benign neoplasm. Placement of colorectal stents may be an option for the palliation of colorectal obstruction secondary to neoplastic disease; however, clinical signs may persist, and continuation of medical management may be necessary.

Topics: Alloys; Animals; Carcinoma in Situ; Colorectal Neoplasms; Dog Diseases; Dogs; Intestinal Obstruction; Male; Palliative Care; Stents

The purpose of this study was to evaluate the usefulness of self-expanding nitinol stents for palliative treatment of malignant colorectal obstruction caused by unresectable extrinsic tumor, colorectal metastasis, or peritoneal seeding.. One covered stent and 10 uncovered stents were deployed in eight patients with colorectal obstruction due to extrinsic tumor under fluoroscopic guidance. The sites of obstruction were located in the rectum (n = 5), in the rectosigmoid colon (n = 2), and from the transverse colon to the descending colon (n = 1). Clinical usefulness and complications were analyzed.. Stents were placed successfully in all patients. Minor modifications of the delivery system were required in the tortuous rectosigmoid and lower rectum strictures. Symptoms of obstruction were initially resolved in all but one patient. In that patient, the presence of other points of obstruction was suspected. Bowel obstruction recurred in two patients: one obstruction was due to migration of a covered stent 4 days after the procedure, and the other obstruction was due to peritoneal seeding 33 days after the procedure. Both required colostomy or ileostomy. All patients died 12-111 days after stent placement (mean, 56 days). In five patients (63%), colonic obstruction was palliated by placing a stent until the patients' death between 39 and 111 days after stent placement (mean, 62 days). Six complications occurred in four patients and included stent migration (n = 1), anal bleeding (n = 2), anal pain that required analgesia (n = 1), and fever (n = 2). CONCLUSION; This self-expandable nitinol stent adequately palliated 63% of patients with colonic obstruction due to extrinsic tumor in this small series. Patient selection is very important to the success of this treatment.

Topics: Alloys; Colonic Diseases; Colorectal Neoplasms; Female; Humans; Intestinal Obstruction; Male; Middle Aged; Neoplasms; Palliative Care; Patient Selection; Peritoneal Neoplasms; Rectal Diseases; Stents