Nitinol coil esophageal prosthesis: advantages of removable self-expanding metallic stents

EsophaCoil for palliation of dysphagia in unresectable oesophageal carcinoma: short- and long-term results

BACKGROUND AND AIM

Few reports have shown that EsophaCoil is an effective and safe prosthesis for palliation of malignant oesophageal dysphagia. A single centre experience using this type of prosthesis is reported.

PATIENTS AND METHODS

Between January 1995 and September 2000, 42 consecutive patients, 41 with unresectable oesophageal cancer and one with oesophageal stenosis secondary to lung cancer, were treated with 44 EsophaCoils (2 patients received 2 stents). Tumours were located in lower third of oesophagus and/or gastric cardia in 22 cases, in middle third in 18 and in upper third in 2. Mean stricture length was 5.3 cm. Implantation was performed on hospitalized patients.

RESULTS

EsophaCoil placement was successful all 44 times and was followed by complete expansion of the prostheses. There were no major procedure-related complications or deaths. Dysphagia score improved from mean of 2.9 to 1.3 within 24 hours of stent implantation. Median hospital stay was 2.7 days. Late complications occurred in 14 patients (34.2%): 3 migrations into stomach, 7 tissue overgrowth, 2 late perforations and 2 food impactions. Mean survival time was 4.2 months (range 1-10).

CONCLUSIONS

In our experience, full expansion of EsophaCoil was achieved in all cases. This result, was associated with high incidence of retrosternal pain. Relief of dysphagia score was identical to that obtained with other types of Self-Expanding Metal Stent. Coil design prevented tumour ingrowth and allowed retrieval of three migrated stents. Mean survival time was similar to that reported in larger series using different types of Self-Expanding Metal Stent.

A comparison of 3 types of covered metal stents for the palliation of patients with dysphagia caused by esophagogastric carcinoma: a prospective, randomized study

BACKGROUND

There are currently 3 types of covered metal stents available in Europe for palliation of patients with malignant dysphagia. Their relative merits have not been compared in a prospective, randomized study.

METHODS

One hundred consecutive patients with esophagogastric carcinoma were randomized to placement of an Ultraflex stent, a Flamingo Wallstent, or a Gianturco-Z stent. Malignant strictures of the esophagus were treated by insertion of a small-diameter stent (n = 71), whereas those involving the gastric cardia were treated with a large-diameter stent (n = 29).

RESULTS

At 4 weeks, dysphagia had improved in all patient groups (p < 0.001), but the degree of improvement did not differ among the 3 groups (p = 0.14). There were differences among the 3 stent types with respect to major complications (Ultraflex stent: 8/34 [24%], Flamingo Wallstent: 6/33 [18%], and Gianturco-Z stent: 12/33 [36%]), but these were not statistically significant (p = 0.23). Nine patients (26%) with an Ultraflex stent, 11 (33%) with a Flamingo Wallstent, and 8 (24%) with a Gianturco-Z stent had recurrent dysphagia (p = 0.73), mainly because of tumor overgrowth or stent migration; 12 of 13 episodes of migration involved small-diameter stents in the esophagus.

CONCLUSIONS

All 3 covered metal stents evaluated offer the same degree of palliation of patients with malignant dysphagia. Placement of Gianturco-Z stents was associated with more complications as compared with Ultraflex stents and Flamingo Wallstents. Although stent migration is reduced by increasing stent diameter, tumor overgrowth remains an intractable problem that requires a new approach.

Expandable metal stents in achalasia--is there a role?

OBJECTIVE

Achalasia is treated with pneumatic dilation or myotomy, and botulinum toxin injections are occasionally used. We review our community's experience with expandable metal stents in six patients who failed medical treatment or were poor surgical candidates.

METHODS

Eight stents were placed in six patients between July 1995 and November 1997. Four patients had achalasia and two pseudoachalasia. Four patients underwent successive botulinum toxin injections. One patient only agreed to periodic Maloney dilatations or a stent. Pneumatic dilation was performed in one patient and considered high risk in the rest. All were poor surgical candidates. Three different stents were used: Gianturco Rosch Z stent, Wallstent I, and Wallstent II.

RESULTS

One-month mortality and morbidity were 33% and 50%, respectively. Two patients were asymptomatic on a liquid diet for > or =6 months but required repeat endoscopy for recurrent dysphagia because of food bolus impaction and proximal stent migration in each.

CONCLUSIONS

Expandable metal stents in achalasia or pseudoachalasia do not provide sustained symptom relief, and their use is associated with unacceptably high morbidity and mortality. We do not recommend the use of these devices in patients who have failed medical therapy or who are poor surgical candidates.

A new design metal stent (Flamingo stent) for palliation of malignant dysphagia: a prospective study. The Rotterdam Esophageal Tumor Study Group

BACKGROUND

Metal stents are not superior to conventional endoprostheses with respect to the incidence of recurrent dysphagia because of tumor ingrowth with uncovered stents and migration with their covered counterparts. To overcome these limitations, a partially covered (inside-out covering) metal stent with a conical shape and a varying braiding angle of the mesh along its length, the Flamingo stent, has been developed.

METHODS

From March 1997 to October 1997, 40 consecutive patients with dysphagia due to malignant tumors had either a small diameter (proximal/distal diameter 24/16 mm; n = 21) or a large diameter Flamingo stent (proximal/distal diameter 30/20 mm; n = 19) placed.

RESULTS

There was statistically significant improvement in dysphagia, but improvement was not greater with large diameter stents compared to small diameter stents (p = 0.21). Major complications (bleeding [4], perforation [1], fever [1] and fistula [1]) occurred in 7 (18%) patients. Large diameter stents tended to be associated with more major complications than small diameter stents (5 vs. 2; p = 0.07). Pain following stent placement was observed in 9 (22%) patients and occurred more frequently in those who had prior radiation and/or chemotherapy (p = 0.02). Recurrent dysphagia (mainly due to tumor overgrowth) occurred in 10 (25%) patients.

CONCLUSIONS

Flamingo stents are effective for palliation of malignant dysphagia, but the large diameter stent seems to be associated with more complications involving the esophagus than the small diameter stent. Because recurrent dysphagia is mainly due to tumor progression, further technical developments in stent design are needed.

Self-expandable metal stents for malignant dysphagia

BACKGROUND

The use of self-expandable metal stents in relieving dysphagia for patients with incurable malignant oesophageal strictures was retrospectively evaluated.

METHODS

Between September 1993 and August 1996, 66 male and 16 female patients with a median age of 72 years received self-expandable metal stents for malignant dysphagia. Six patients had concurrent tracheo-oesophageal fistulas. All patients were stented under sedation and stent insertion was performed under fluoroscopic guidance.

RESULTS

Stent placement was successful in 80 patients (98%). There were seven early complications (inaccurate positioning (n = 3), migration (n = 1), incomplete expansion (n = 1), intractable pain (n = 1), and perforation (n = 1)). Two complications were lethal and three were treated endoscopically. Mean dysphagia grade improved from 3.2+/-0.7 to 1.8+/-0.9 (P < 0.05) after implantation. All tracheo-esophageal fistulas were successfully occluded. Upon a median follow-up of 8 weeks (range: 2-20 weeks), 30 complications developed in 21 patients (tumour overgrowth (n = 15), food bolus obstruction (n = 7), tumour ingrowth (n = 2), buckling of stent (n = 2), tracheo-esophageal fistula (n = 2), bleeding (n = 1), and gastric wall herniation through metal coils (n = 1)). Median survival was 13 weeks (range: 1-82 weeks).

CONCLUSION

Self-expandable metal stents provide useful palliation in patients with incurable malignant dysphagia.

Extraction of migrated self-expanding esophageal metal stents

BACKGROUND

When self-expanding metal stents are used in the palliative treatment of malignant stenoses complications can occur and require the endoscopic extraction of the stent.

METHODS

Three Gianturco-Z stents and two EsophaCoil stents had to be extracted because of migration (4 patients) and strangulation of healthy esophageal tissue between the coil loops during EsophaCoil stent release (1 patient). Because of the strong expansion force of the Gianturco-Z stent, the plastic sheath of a polypectomy snare was replaced by the steel sheath of a basket used for mechanical lithotripsy of bile duct stones. The sufficient resistance of the steel sheath allowed the stents to be compressed. The EsophaCoil stents were gradually retracted with a polypectomy snare over a plastic tube.

RESULTS

All stents could be extracted successfully. There were no severe complications related to extraction.

CONCLUSION

By means of the endoscopic extraction techniques described above, it is possible to safely remove self-expanding esophageal stents.

Expandable metallic prostheses for malignant obstructions of gastric outlet and proximal small bowel

BACKGROUND

Data are limited on use of expandable metal stents for treatment of malignant gastric outlet obstruction. Accordingly, we report our experience using these stents to palliate malignant obstructions of the gastric outlet, duodenum, and proximal jejunum.

METHODS

Eight patients with malignant strictures causing gastric obstruction underwent endoscopy with fluoroscopic guidance to delineate tumor borders and length followed by expandable metallic prosthesis placement (Wallstent, Z-Stent, Ultraflex, and Endocoil).

RESULTS

Symptoms were relieved in seven patients, five of whom had previous surgeries (Whipple, Billroth II, esophagojejunostomy, and gastrojejunostomy) for malignancy. One patient underwent surgical resection of a presumed malignant stricture containing a previously placed Wallstent after a 45-pound weight gain.

CONCLUSIONS

Expandable metallic prostheses placed in patients with malignant obstruction of the gastric outlet, duodenum, or proximal jejunum, before or after surgery, effectively palliate obstructive symptoms and may also serve to improve nutrition.

Use of the 25 mm flanged esophageal Z stent for malignant dysphagia: a prospective multicenter trial

BACKGROUND

An initial multicenter study using a 21 mm flanged esophageal Z stent demonstrated excellent palliation but an 11% immediate complication rate at placement and a 27% migration rate at 1 month. This North American multicenter trial prospectively studied a 25 mm flanged Z stent to define its palliative ability and whether the increased diameter affected placement or migration problems.

METHODS

Fifty patients who had esophageal Z stents at seven university or regional referral hospitals were prospectively studied. Indications for prosthesis placement, previous therapy, patient demographics, incidence of concomitant tracheoesophageal fistula, and degree of dysphagia were defined, as were procedural and subsequent stent-related problems, survival times, the ability to occlude a tracheoesophageal fistula, and subsequent degree of dysphagia.

RESULTS

Twenty-four patients had infiltrating malignancy (16 exophytic and 10 extrinsic), 9 of whom had concomitant tracheoesophageal fistulas. Ten patients (20%) had misplaced stents requiring retrieval and replacement, 12 patients (24%) had subsequent stent-related problems including exsanguination (2), aspiration (3), tumor overgrowth (3), and postplacement migration (4) (8%). There was statistically significant improvement in prestent versus poststent dysphagia and two thirds of patients had complete occlusion of their tracheoesophageal fistula.

CONCLUSIONS

Redesign of the esophageal Z stent has decreased the migration rate without increasing placement or subsequent erosion problems. Its efficacy appears comparable to the currently marketed Z stent for the palliation of malignant dysphagia and occlusion of tracheoesophageal fistula.

Future directions in interventional pediatric radiology

In conclusion, the explosion of interventional radiology and its impact on the pediatric patient have resulted in a completely new approach to the subspecialty of interventional pediatric radiology. The interventional radiologist has become an integral part of the management of patients and has become directly involved in the day-to-day care of patients. The use of interventional MR imaging recently has been described in clinical trial. Open-configuration magnets that allow full access to the patient and are equipped with instrument tracking systems provide an interactive environment in which biopsies, endoscopic procedures, and minimally invasive interventions or surgeries are performed. In addition, thermal ablation and image-based control of energy deposition also can be performed. Among these procedures, noninvasive MR-guided focused ultrasound ablation has the most promising future and may replace some conventional surgery. The merging of new and exciting technologies including MR, ultrasound, CT, and fluoroscopy into an environment in which both surgical and interventional radiologic procedures can be performed with image guidance is the basis of the operating room of the future. The role of the interventional radiologist as both the imager and interventionalist is central to this procedural environment; however, the interventional radiologist must accept all the responsibilities of imaging, therapy, patient care, and associated complications.