Ultraflex precision colonic stent placement for palliation of malignant colonic obstruction: a prospective multicenter study

ORIGINAL ARTICLE: Clinical Endoscopy

Ultraflex precision colonic stent placement for palliation of malignant colonic obstruction: a prospective multicenter study Alessandro Repici, MD, Diego Fregonese, MD, Guido Costamagna, MD, Remi Dumas, MD, ¨hler, MD, Søren Meisner, MD, Marc Giovannini, MD, Jan Freeman, MD, Georg Ka Lucio Petruziello, MD, Cristina Hervoso, MD, Salvatore Comunale, MD, Roger Faroux, MD Milano, Camposampiero, Roma, Italy, Nice, Marseille, La Roche-sur-Yon, France, Jena, Germany, København, Denmark, Derby, UK

Background: Many patients who develop obstructive colonic symptoms secondary to inoperable colorectal cancer will require palliative treatment. A minimally invasive and potentially long-lasting approach is placement of nitinol self-expanding metal stents (SEMS). Objective: To determine the effectiveness and safety of a nitinol SEMS designed for colorectal use in the palliative treatment of malignant colonic obstruction. Design: Prospective multicenter clinical study. Setting: Nine European study centers. Patients: Forty-four patients with malignant colonic obstruction. Interventions: Placement of nitinol SEMS designed for colorectal use. Main Outcome Measures: Technical success, defined as accurate SEMS deployment with adequate stricture coverage, and clinical success, defined as decompression and relief of obstructive colonic symptoms maintained without intervention or serious device-related complications. Results: Technical success was attained in 95% of patients, with 95% CI 85%-99%. After 6 months, the rate of clinical success was 81%, 95% CI 69%-96%. Survival at 6 months was 67%, 95% CI 54%-84%. Clinical success was maintained until death in 86% of the nonsurvivors. No perforations or SEMS-related deaths occurred. Limitation: This investigation was nonrandomized and did not include a control group. Conclusions: In a large prospective investigation, palliative placement of a nitinol SEMS designed for colorectal use was accomplished with a high rate of technical success. Durable clinical success was achieved in a high proportion of patients with low morbidity. (Gastrointest Endosc 2007;66:920-7.)

Colorectal cancer is among the most common neoplastic diseases, with a reported incidence of 0.56 to 0.85 cases per 1000 person-years in 10 European countries and the United States, corresponding to an estimated 450,000 new cases in 2006 among these countries.1,2 Obstruction has been reported to develop in 16% of patients with colorectal cancer.3 Patients with malignant large-bowel

Copyright ª 2007 by the American Society for Gastrointestinal Endoscopy 0016-5107/$32.00 doi:10.1016/j.gie.2007.03.1042

obstruction usually have advanced colorectal cancer and are often poor operative candidates, yet these patients are in need of treatment and colonic decompression.4,5 Both surgical and nonsurgical treatments have been used to provide palliation for patients with colorectal carcinoma and obstruction. Although surgical colostomy is effective, patients with advanced colorectal malignancies are often extremely poor surgical candidates. Mortality can exceed 10% with the various surgical approaches for relief of large-bowel obstruction.4,6 Moreover, a colostomy worsens the quality of life remaining, and its management poses difficulties for elderly and frail patients.7,8 Nonsurgical approaches, including balloon dilation and ablative methods, such as cryotherapy, electrocoagulation,

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Abbreviations: IQR, interquartile range; SEMS, self-expanding metal stents.

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and laser photocoagulation, generally afford only transient relief of symptoms and require regular repeat treatments.9 Over the last decade, colorectal stent placement has been investigated as an alternative endoscopic method to relieve acute colonic obstruction. Self-expanding metallic stents (SEMS) are an option for definitive primary palliative care that is increasingly gaining favor. SEMS, which can be inserted with the patient under conscious sedation, rapidly decompress the colon and lead to prompt restoration of colonic function. This cost-effective option avoids the potential for surgical morbidity in a typically frail group of patients. Suitable candidates for palliative colonic SEMS placement are patients with obstructive colorectal carcinoma who have extensive local or metastatic disease, are poor risks for surgical resection, or experience recurrent disease after resection.10 The first report on the use of SEMS for palliation in colorectal cancer appeared in 1991.11 Many early reports described the use of stents designed for esophageal or tracheobronchial indications, which were of smaller diameter than is ideal for colorectal strictures. More recently, dedicated colonic stents and delivery systems have been extensively adopted for palliation and preoperative bridging to 1-stage surgical resection of primary colonic tumors. The present multicenter cohort study is among the largest prospective investigation to date of definitive palliative treatment with a SEMS specifically designed for colonic use in patients with lower-bowel obstruction and advanced, disseminated, or inoperable malignant adenocarcinoma.

Self-expanding metal stents for palliation

Capsule Summary What is already known on this topic d

Self-expanding metallic stents (SEMS), an option for definitive primary palliative care in acute colonic obstruction, can be inserted with the patient under conscious sedation, rapidly decompress the colon, and lead to prompt restoration of function.

What this study adds to our knowledge d

In a prospective multicenter study of 44 patients with malignant colonic obstruction, placement of nitinol SEMS was technically feasible in 95% of patients and clinically successful in 81% through a 6-month period.

of another metal stent for the same stricture, and poor fitness for colonoscopy and SEMS placement.

Patient assessments Baseline data were recorded on patient demographics and medical history; date of diagnosis; stricture type, location, length, and pathology; prior anticancer treatment; and duration of obstruction. Additional baseline data were collected on most common bowel habit, dietary restrictions, use of stool softeners, need for mechanical assistance, degree of proximal bowel distension, and ability to pass stool.

SEMS placement

This study was conducted prospectively at 9 European centers between April 2002 and January 2004. One endoscopist was responsible for SEMS placement at each study center. Approval of the study protocol was obtained from the institutional ethics committees of the participating centers, and all patients gave their written informed consent. Study inclusion criteria were a diagnosis of colorectal stricture because of a malignant intrinsic endoluminal tumor or tumor recurrence after surgical resection; the presence of clinical obstructive colorectal symptoms; age R18 years; and a Karnofsky Performance Status R20%. The stricture must have been situated no more than 40 cm from the insertion point of the colonoscope so that placement of the study SEMS was feasible. Patients with resectable disease that required stents as a bridge to surgery were not included in this study. Exclusion criteria consisted of the following: benign stricture, perforated colon, extrinsic compressive tumor, concurrent radiotherapy for the colorectal stricture or treatment with an investigational drug or device within the preceding 4 weeks, placement

Patients received the over-the-wire Ultraflex Precision Colonic Stent (Microvasive Endoscopy, Boston Scientific Corp, Natick, Mass) with a 25-mm stent body, 30-mm proximal flare, and mesh construction of nitinol nickel-titanium alloy, a material with ‘‘shape memory’’ that facilitates expansion inside the bowel to a predesigned configuration (Fig. 1). The over-the-wire delivery system can accommodate the 30-mm maximum flared diameter of the SEMS, whereas delivery of dedicated colonic stents through the endoscope is currently restricted to smaller diameters (20-22 mm). A larger diameter may confer the potential for more complete and lasting relief of obstruction. This SEMS is available in lengths of 6, 9, and 12 cm. The diameter of the SEMS is comparatively large and, together with a flared design, may serve to reduce the likelihood of migration. The wire SEMS strands are arrayed in a diamond configuration and welded at the ends. The SEMS design is intended to resist radial compression and allow compliance with bends in the colorectal anatomy without collapsing. The SEMS delivery system is 105 cm in length. Sedation, if required, was administered in accord with standard practice of the participating centers. Patients were initially placed in the left lateral decubitus position, and rotation of the patient into the supine position was

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PATIENTS AND METHODS Patients

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Descriptive statistics of continuous data were the median and interquartile range (IQR). The percentage of patients with technical success was calculated with an exact binomial 95% CI. Times to clinical failure and death were estimated by the Kaplan-Meier product limit method. Stata 9.1 (Stata Corp, College Station, Tex), SPSS 11.5 (SPSS Inc, Chicago, Ill), and StatXact 7.0 (Cytel Software Corp, Cambridge, Mass) statistical software were used for data analysis.

RESULTS Figure 1. Ultraflex Precision colonic stent mounted in deployment system and (inset) detailed view of fully expanded stent.

allowed as needed to improve the anatomic view under fluoroscopy. Procedures were performed under fluoroscopic and, optionally, endoscopic control. The stricture was gently cannulated with a stiff guidewire. After estimation of stricture length, a SEMS length was selected with allowance for extension3 1 cm beyond both the proximal and distal stricture margins. The SEMS delivery system was then advanced over the guidewire under fluoroscopic guidance, and, if desired, the endoscope was reintroduced into the colon beside the stent catheter. After longitudinal centering of the stent in relation to the stricture, deployment was commenced by retracting the delivery catheter pull ring and thereby releasing the suture knots. The sutures unraveled starting from the proximal end of the delivery catheter. Stent release was monitored by fluoroscopy and optional endoscopy to ensure centering along the stricture site. Representative endoscopic and radiographic images of SEMS placement are provided in Figure 2. After the procedure, patients were maintained on clear fluids for at least 24 hours. Patients were assessed at the time of SEMS placement and at follow-up evaluations approximately 1 week and 1, 3, and 6 months thereafter. Obstructive bowel symptoms, any therapeutic interventions, and the occurrence of adverse events were documented at each follow-up visit.

Forty-four patients were enrolled in the study. The diagnosis was adenocarcinoma in 40 patients (91%), metastatic disease in 2 (5%), benign stricture at the colorectal anastomosis in 1 (2%), and indeterminate malignancy in 1 (2%). Intrinsic strictures were present in 43 patients (98%) and extrinsic in 1 (2%). The patient with an extrinsic stricture was diagnosed with ovarian cancer and enrolled in deviation from the study protocol, which called for exclusion of patients with extrinsic strictures. A second protocol deviation was the enrollment of 1 patient with a tumor of benign etiology, notwithstanding the eligibility criterion of malignant disease. Additional baseline data are summarized in Table 1.

Technical success

Primary study outcome measures were evaluated on both an intention-to-treat and a per-protocol basis.

Placement of 50 total SEMS was attempted in the 44 study patients (Table 2). The median duration of the stent placement procedure was 25 minutes (range 15-38 minutes). Initial expansion O65% was attained with 73% of SEMS deployed. Before SEMS placement, balloon dilation was performed in 3 patients with lumen diameters of 3 to 5 mm and bougienage by using savory dilators in 3 patients with 3- to 6-mm lumen diameters. Balloon dilation was also successfully performed in 1 patient after stent placement for the purpose of increasing stent expansion to 25 mm. In 38 of 44 patients (86%), placement of a single SEMS spanning the target stricture succeeded on the first attempt. In 1 patient, SEMS placement was successful on the second attempt 48 hours after the first. Three patients required a second stent because of underestimation of the necessary SEMS length, and 2 patients had a second stent because of deployment errors. All 5 second stents were placed on the same day as the first stent. In 1 of these 5 patients, a second stricture, 40 cm proximal to the first, was discovered during the SEMS placement procedure, and an inability to pass an endoscope or guidewire through the distal stricture precluded placement of a stent at the distal site. This patient, who had entered the study despite ineligibility because of an extrinsic stricture, was classified as a technical failure and subsequently underwent colostomy. A second patient was scored as a technical

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Outcomes The primary study outcome measures were technical and clinical successes. Technical success was defined as accurate SEMS deployment, with adequate stricture coverage. The definition of clinical success was decompression and relief of obstructive colonic symptoms maintained without intervention or serious device-related complications.

Statistical analysis

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Self-expanding metal stents for palliation

Figure 2. A and B, Endoscopic views of SEMS placement. C to E, Radiographic views of SEMS placement.

failure, because the SEMS could not be advanced to the stricture site and, therefore, the placement attempt had to be abandoned. Instead, the patient received an Enteral Wallstent (Microvasive).

Because spanning of the strictures by SEMS placement was ultimately attained in 42 of 44 patients, the rate of technical success was 95%, 95% CI 85%-99% by intention to treat. With exclusion of the 2 patients enrolled in

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TABLE 1. Baseline patient data (n Z 44)

TABLE 2. SEMS placement data

Characteristic

Parameter

No.

%

Age, median (IQR) (y)

74 (65-81)

Karnofsky Performance Status, median (IQR)

70 (60-80)

6

13

26

Stricture length, median (IQR) (cm)

5 (4-8)

9

28

56

Stricture lumen diameter, median (IQR) (mm)

6 (5-9)

12

9

18

Duration of obstruction, median (IQR) (d)

6 (3-12)

Camposampiero, Italy

13

26

Sex, no. (%)

Stent lengths (cm)

No. stents per center

Men

28 (64)

Turin, Italy

13

26

Women

16 (36)

Rome, Italy

7

14

Nice, France

6

12

Patients per center, no. (%) Camposampiero, Italy

12 (27)

Jena, Germany

5

10

Turin, Italy

12 (27)

Copenhagen, Denmark

2

4

Rome, Italy

6 (14)

Marseille, France

2

4

Nice, France

5 (11)

Derby, UK

1

2

Jena, Germany

3 (7)

La Roche-sur-Yon, France

1

2

Copenhagen, Denmark

2 (5)

No. stents placed per patient

Marseille, France

2 (5)

0

1

2

Derby, UK

1 (2)

1

38

87

La Roche-sur-Yon, France

1 (2)

2

5

11

Stricture location, no. (%)

Initial expansion of deployed stents (%)

Sigmoid colon

17 (39)

%65

13

27

Rectum

16 (36)

O65

35

73

Colorectal anastomosis

4 (9)

Rectosigmoid junction

3 (7)

Splenic flexure

2 (5)

Descending colon

1 (2)

Transverse colon

1 (2)

Occlusive syndrome Total obstruction, no. (%)*

10 (23)

Incomplete obstruction, no. (%)

34 (77)

Most frequent obstructive bowel symptoms, no. (%) Bloating

20 (45)

Abdominal/perianal pain

17 (39)

Decreased stool caliber

13 (30)

Hematochezia

11 (25)

Rectal bleeding

11 (25)

*Among the 10 patients who presented with total obstruction, the median time expired between onset of obstruction and SEMS placement was 3 days (IQR 2-5 days) compared with 8 days (4-25 days) for the 34 patients with incomplete obstruction.

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deviation from the protocol eligibility criteria, the technical success rate in the per protocol patient subset was 41 of 42 (97%, 95% CI 87%-100%).

Clinical success Initial decompression and relief of obstructive symptoms were accomplished in 42 of 44 patients. The 2 patients with technical failure of SEMS placement were scored as clinical failures on day 0 because of unsuccessful decompression and unrelieved obstructive symptoms. During follow-up after SEMS placement, clinical failure occurred in 6 additional patients. The median time at risk for clinical failure was 174 days (range 85-186 days). At 6 months, the rate of clinical success was 81% by intention to treat (Fig. 3). The clinical success rate did not differ between patients presenting with total versus incomplete occlusion (P Z .75 by 2-sided exact log-rank test). In the per-protocol subset of 42 patients, the clinical success rate at 6 months was 83%, 95% CI 70%-97%. In 1 of the 6 patients failing during follow-up, distal tumor progression caused obstructive symptom recurrence by the 6-month visit. Hematochezia, probably related to www.giejournal.org

Repici et al

radiation colitis and possibly also to the SEMS, was the basis for failure in a second case. The hematochezia resolved with medical management. A third patient required balloon dilation and laser therapy for tumor overgrowth below the stent. In a fourth patient, the SEMS had migrated to the lower rectum after 2 months and was removed with a snare. Migration was attributed to tumor reduction after chemotherapy, and a replacement SEMS was considered unnecessary. In a fifth patient, failure was from recurrent obstructive symptoms and severe device-related pain, which prompted surgical removal of the stent and permanent colostomy. Colonoscopy just before removal demonstrated that the SEMS remained fully patent in its original position, without tumor ingrowth or overgrowth. In the final case, tumor ingrowth that did not require intervention was noted at the final follow-up evaluation 331 days after stent placement. In summary, recurrence of obstructive symptoms was the sole basis for failure in 1 patient and a serious device-related complication in 2, whereas 2 patients failed because of both a serious device-related complication and the need for intervention and in 1 patient because of both these reasons plus obstructive symptom recurrence. Thus, a total of 5 patients (11%) experienced 1 serious device-related complication each, namely, hematochezia, tumor overgrowth, SEMS migration, pain, and tumor ingrowth. No perforations were encountered.

Self-expanding metal stents for palliation

Figure 3. Kaplan-Meier estimated fractions of patients with clinical success (solid line) and 95% CI (dashed line). Tick marks on Kaplan-Meier curve show times of individual patient censoring.

Survival During the study, 14 deaths occurred; none were stent related. At the time of death, 12 of the nonsurvivors (86%) were clinical successes, and, hence, stent placement served its palliative purpose over the remaining life span of these patients. The median time at risk for death was 175 days (101-186 days). The survival rate at 6 months was 67% by intention to treat (Fig. 4) and 68%, 95% CI 54%-85% per protocol. No difference in survival could be detected between the patients with total and with incomplete occlusion at baseline (P Z .17 by 2-sided exact log-rank test in intent-to-treat population).

DISCUSSION

Figure 4. Patient survival based on Kaplan-Meier analysis.

Placement of colonic stents to treat malignant bowel obstruction may provide an effective means of intestinal decompression, avoiding urgent surgery and its complications, and allowing the medical condition of eligible patients to be improved and the colon to be adequately prepared for elective surgery.12 In patients with inoperable tumors, stents may offer long-term palliative treatment and avoidance of a permanent colostomy. The findings of this multicenter prospective trial further demonstrate the utility of SEMS for definitive palliative treatment of malignant colorectal strictures. SEMS can provide rapid and effective relief of obstructive symptoms, with

low morbidity. The SEMS placement procedure, typically performed with the patient under conscious sedation, entails less acute debilitation, more rapid recovery, and a shorter hospital stay compared with surgical alternatives.13-15 Such benefits are of particular value in patients with limited life expectancy. Stent placement also does not preclude the use of palliative chemoradiotherapy when appropriate.16 A recent systematic review supported the conclusion that ‘‘palliative colorectal stenting has the potential to be the first choice modality in patients with advanced colorectal cancer presenting with obstruction.’’17

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TABLE 3. Prospective trials of SEMS for palliation of malignant colonic obstruction* Success rate (%) Trial

Technical

Clinical

Perforation

Migration

Wallstent, Ultraflex, or other

88

82

24

6

16

Ultraflex esophageal stent

94

81

6

13

36

Cook Endoscopy SEMS (Winston-Salem, NC)

97

78

6

11

16

Memotherm colorectal SEMS (Bard, Murray Hill, NJ)

81

81

0

0

2003

52

Enteral or esophageal Wallstent or other

98

96

2

15

24

48

Wallstent, Choo-Stent (Seoul, Korea), or Memotherm

92

92

0

16

44

Ultraflex Precision colonic SEMS

95

81

0

2

19

1998

20

2000

Baron et al,

Repici et al,

21

Spinelli and Mancini, 22

Clark et al, Law et al,

13

2003

Ptok et al, 2006 Present trial

2001

N

SEMS

17

Incidence (%)

*Prospective series with fewer than 15 patients not included.

All 3 comparative studies to date have indicated advantages of stents over surgery.13-15 In a nonrandomized study of 61 patients, stent placement was associated with less need for intensive care, a lower frequency of stoma creation, and a shorter hospital stay when compared with emergency surgery.13 Another comparative study of 35 patients showed significant shortening of time to initiation of oral intake and duration of hospital stay after decompression in patients who received stents versus those who underwent colostomy.15 In a randomized trial of 22 patients, endoscopic placement of the same nitinol SEMS used in the present study accelerated restoration of bowel function and oral intake compared with colostomy.14 Operative time and median duration of hospitalization were reduced. Significant differences in morbidity and mortality could not be detected, although the trial was of limited statistical power to assess these end points. Patients in the randomized trial14 were followed after stent placement only until hospital discharge, and the investigators acknowledged the need for confirmatory studies delineating longer-term outcomes. The present investigation helps fulfill this need by virtue of its prospective design, longer-term follow-up, and a larger patient population than in similar previous studies. At 6 months, the rate of clinical success was 81% based on Kaplan-Meier analysis and intention to treat. Of the patients who died during follow-up, 86% were clinical successes. Two systematic reviews17,18 summarized clinical success in previous studies; however, only crude success rates were provided, without accounting for duration of follow-up and censoring, and, consequently, those rates cannot be directly compared with the Kaplan-Meier estimated fraction at 6 months in the present study. Stomas were avoided in all but 2 patients in the present study. One of the 2 had been diagnosed with extrinsic ovarian cancer and developed multiple obstructions, whereas,

in the other patient, the proximity of the stricture to the rectum resulted in tenesmus and pain. Tumor overgrowth that required intervention occurred in only 1 patient at 92 days. The colonic nitinol SEMS was successfully deployed in 95% of patients. This rate of technical success is consistent with that reported for previous prospective clinical trials of SEMS for palliation (Table 3).13,19-24 As with all procedures, there is a learning curve, and, in 2 cases, the stent was not properly deployed initially, but a second attempt successfully decompressed the bowel. High rates of technical success were achieved in most colorectal stent studies, because almost 90% of strictures that caused large-bowel obstruction are located at or distal to the splenic flexure. This distal location allows for relatively easy insertion and deployment of the stent. Perforation is the complication of greatest clinical concern in SEMS placement. The greatest risk of perforation is in the rectosigmoid area, especially the rectosigmoid junction.17 A higher probability of perforation appears to confront patients who have had balloon predilation, and its use is not recommended.18 Even though balloon dilation was performed on 3 patients before stent placement, no perforations were observed in the present study. Stent migration occurred in only 1 patient (2%). This patient started chemotherapy 2 days after stent placement, and migration was attributed to the resultant tumor reduction. In a recent systematic review of the efficacy and safety of colorectal stents, migration was found to be notably more frequent after laser pretreatment or chemotherapy, as well as in patients with strictures of benign etiology.18 The 2% migration rate was lower than that in several other similar prospective trials, possibly because of the large-diameter flared design of the investigated SEMS; however, the present study was not powered to quantify migration rate with high precision, and the 95% CI around the 2% rate (0%-12%) was relatively wide.

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Nitinol appears to be particularly well suited as a SEMS material. A large radial expansile force is spontaneously and evenly generated. The final diameter is reached over the course of 2 to 5 days, so that dilation of the stricture is gentle, as well as effective.25 Predilation is not generally necessary, and the potential for migration is reduced, obviating sharp hooks in the stent design. The flexibility of a fine-mesh nitinol SEMS allows easier passage through colonic curvature and even permits some degree of peristaltic movement. In the present study, high rates of technical success and durable clinical relief of obstructive symptoms were achieved after palliative placement of a nitinol SEMS designed for colorectal use. Based on its effectiveness, safety, and relative simplicity, SEMS placement offers patients with unresectable colorectal cancer and obstructive symptoms an attractive minimally invasive and cost-effective alternative to surgery.

ACKNOWLEDGMENT We thank Roberta J. Navickis, PhD, and Mahlon M. Wilkes, PhD, for their contributions in the statistical analysis of the study data and preparation of the manuscript. DISCLOSURE There are no commercial associations (eg, equity ownership or interest, consultancy, patent and licensing agreement, or institutional and corporate associations) that might be a conflict of interest in relation to this article. Grant support was provided by Microvasive Endoscopy, Boston Scientific Corp, Natick, Massachusetts.

Self-expanding metal stents for palliation 9. Gevers AM, Macken E, Hiele M, et al. Endoscopic laser therapy for palliation of patients with distal colorectal carcinoma: analysis of factors influencing long-term outcome. Gastrointest Endosc 2000;51:580-5. 10. Baron TH. Indications and results of endoscopic rectal stenting. J Gastrointest Surg 2004;8:266-9. 11. Dohmoto M. New method: endoscopic implantation of rectal stent in palliative treatment of malignant stenosis. Endosc Dig 1991;3:1507-12. 12. Zollikofer CL, Jost R, Schoch E, et al. Gastrointestinal stenting. Eur Radiol 2000;10:329-41. 13. Law WL, Choi HK, Chu KW. Comparison of stenting with emergency surgery as palliative treatment for obstructing primary left-sided colorectal cancer. Br J Surg 2003;90:1429-33. 14. Fiori E, Lamazza A, de Cesare A, et al. Palliative management of malignant rectosigmoidal obstruction. Colostomy vs. endoscopic stenting. A randomized prospective trial. Anticancer Res 2004;24:265-8. 15. Tomiki Y, Watanabe T, Ishibiki Y, et al. Comparison of stent placement and colostomy as palliative treatment for inoperable malignant colorectal obstruction. Surg Endosc 2004;18:1572-7. 16. Harris GJ, Senagore AJ, Lavery IC, et al. The management of neoplastic colorectal obstruction with colonic endolumenal stenting devices. Am J Surg 2001;181:499-506. 17. Sebastian S, Johnston S, Geoghegan T, et al. Pooled analysis of the efficacy and safety of self-expanding metal stenting in malignant colorectal obstruction. Am J Gastroenterol 2004;99:2051-7. 18. Khot UP, Lang AW, Murali K, et al. Systematic review of the efficacy and safety of colorectal stents. Br J Surg 2002;89:1096-102. 19. Baron TH, Dean PA, Yates MR 3rd, et al. Expandable metal stents for the treatment of colonic obstruction: techniques and outcomes. Gastrointest Endosc 1998;47:277-86. 20. Repici A, Reggio D, De Angelis C, et al. Covered metal stents for management of inoperable malignant colorectal strictures. Gastrointest Endosc 2000;52:735-40. 21. Spinelli P, Mancini A. Use of self-expanding metal stents for palliation of rectosigmoid cancer. Gastrointest Endosc 2001;53:203-6. 22. Clark JS, Buchanan GN, Khawaja AR, et al. Use of the Bard Memotherm self-expanding metal stent in the palliation of colonic obstruction. Abdom Imaging 2003;28:518-24. 23. Law WL, Choi HK, Lee YM, et al. Palliation for advanced malignant colorectal obstruction by self-expanding metallic stents: prospective evaluation of outcomes. Dis Colon Rectum 2004;47:39-43. 24. Ptok H, Meyer F, Marusch F, et al. Palliative stent implantation in the treatment of malignant colorectal obstruction. Surg Endosc 2006;20: 909-14. 25. Akle CA. Endoprostheses for colonic strictures. Br J Surg 1998;85:310-4.

REFERENCES 1. Bingham SA, Day NE, Luben R, et al. Dietary fibre in food and protection against colorectal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC): an observational study. Lancet 2003;361:1496-501. 2. Michels KB, Fuchs CS, Giovannucci E, et al. Fiber intake and incidence of colorectal cancer among 76,947 women and 47,279 men. Cancer Epidemiol Biomarkers Prev 2005;14:842-9. 3. Phillips RK, Hittinger R, Fry JS, et al. Malignant large bowel obstruction. Br J Surg 1985;72:296-302. 4. Deans GT, Krukowski ZH, Irwin ST. Malignant obstruction of the left colon. Br J Surg 1994;81:1270-6. 5. Lopez-Kostner F, Hool GR, Lavery IC. Management and causes of acute large-bowel obstruction. Surg Clin North Am 1997;77:1265-90. 6. Riedl S, Wiebelt H, Bergmann U, et al. Post operative komplikationen und letalita¨t in der chirurgischen therapie des coloncarcinoms [German]. The Colorectal Carcinoma Study Group. Chirurg 1995;66:597-606. 7. Sprangers MA, Taal BG, Aaronson NK, et al. Quality of life in colorectal cancer. Stoma vs. nonstoma patients. Dis Colon Rectum 1995;38: 361-9. 8. Nugent KP, Daniels P, Stewart B, et al. Quality of life in stoma patients. Dis Colon Rectum 1999;42:1569-74.

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Received December 14, 2006. Accepted March 5, 2007. Current affiliations: Servizio di Endoscopia Digestiva, IRCCS IstitutoClinico Humanitas (A.R., C.H., S.C.), Milano, Italy, Unita` di Gastroenterologia, Presidio Ospedaliero di Camposampiero (D.F.), Camposampiero, Italy, Endoscopia Digestiva Chirurgica (G.C., L.P.), Policlinico Agostino Gemelli, Universita` Cattolica del Sacro Cuore, Roma, Italy, Digestive Endoscopy Unit, Centre Hospitalier Universitaire Nice Archet 2 (R.D.), Nice, France, Arbeitsbereich Chirurgische Endoskopie (G.K.), Klinikum der Friedrich-Schiller-Universita¨t Jena, Jena, Germany, H.S. Bispebjerg Hospital, København, Denmark, Digestive Endoscopy Unit, Institut Paoli-Calmettes (S.M.), Marseille, France, Gastroenterology and Liver Unit (J.F.), Derby City General Hospital, Derby, UK, Service Gastro-ente´rologie–Endoscopie digestive (R.F.), Centre Hospitalier De´partemental, La Roche-sur-Yon, France. Presented at Digestive Disease Week, Orlando, Florida, May 17-23, 2003, and the 11th United European Gastroenterology Week, Madrid, Spain, November 1-5, 2003. Reprint requests: Alessandro Repici, MD, Servizio di Endoscopia Digestiva, IRCCS Istituto Clinico Humanitas, Via Manzoni 56, Rozzano (MI), 20089 Italy.

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