Colorectal cancer is the third and second most common global cancer in males and females, respectively, and is showing increasing levels of morbidity in China [
The self-expandable metallic stent (SEMS) has been applied in clinical practice since the 1990s, which is an alternative form of emergency treatment for malignant colon obstruction. The SEMS is considered to function as a bridge to elective resection and allow the preparation for surgery in a much more efficient manner. The results of several nonrandomized studies have demonstrated that the placement of SEMS, combined with elective resection, can significantly improve short-term outcomes, including a lower postoperative complications rate and a shorter hospital stay [
The aim of our study was to investigate the feasibility of a SEMS as a bridge to surgery for malignant colonic obstruction by comparing the short- and long-term outcomes of the patients treated with the SEMS combined with elective surgery to those with emergency surgery only.
The design of our study was approved by the Institutional Review Board (no. 2017209). We retrospectively reviewed patients who were admitted in our hospital between 2010 and 2017. Patients who met the following inclusion criteria were included in the study: pathologically diagnosed with colon cancer, either before or after surgery; accompanied by acute obstruction which was determined by clinical manifestations, physical examinations, and abdominal imaging examinations; performing SEMS placement or emergency surgery with curative intent; resectable synchronous liver metastasis and local advanced cancer were indications for surgery with curative intent. Patients who were diagnosed with obstruction combined with perforation were excluded from the study.
Either SEMS placement or emergency surgery was performed if symptoms persisted or worsened after attempting conservative treatments within 72 h. The choice between these two management styles was made by the attending surgeon and by patient preference. All the SEMSs in our study were inserted by three experienced interventional radiologists under fluoroscopic guidance of a digital subtraction angiography machine. A catheter was placed through the anus to the distal point of the lesion, and a contrast medium was injected to visualize the lumen of the colon. We then inserted a standard or hydrophilic guidewire through the lesion. We estimated the length of stenosis and delivered a suitable uncovered SEMS using a superstiff guidewire through the lesion. The SEMS was then released after confirming that the two ends of the stent extended 2-3 cm beyond the margins of the stricture (Figure
(a) Filling defect showed the location and length of lesion (arrow). (b) A stent (arrow) was placed and obstruction was relieved after the procedure. (c) A constricted SEMS (arrow) on the conveyer.
The type of emergency surgery carried out was determined by three experienced general surgeons depending on intraoperative findings and the individual condition of the patient following colonic lavage during surgery. Generally, one-stage radical resection, or Hartmann’s procedure, was attempted.
The baseline characteristics of the patients in the two groups were collected from the hospital database, including age, sex, previous/preexisting diseases, body mass index (BMI), American Society of Anesthesiologists (ASA) class, oncological information, and laboratory examinations prior to surgery. The condition of previous/preexisting diseases was externalized as Charlson’s weighted index of comorbidities (WIC) and oncological information, including tumor location, pathological stage, differentiation degree, and perineural/vascular invasion. Surgical characteristics included operative approach, resection margin, stoma formation, surgery duration, and intraoperative blood loss. Postoperative complications were classified into five levels of severity according to the Clavien–Dindo grading system. As paregoric or total parenteral nutrition was routine postoperative prescription for patients with colonic cancer, they were not counted as postoperative complications in this study. The SEMS-related characteristics were also collated, including technical success, clinical success, interval between stent and surgery, and stent-related complications. All patients were followed up periodically until death or March 2020, in adherence to the follow-up strategy described by the National Comprehensive Cancer Network (NCCN) Guidelines. Three-year overall survival, as long-term outcomes, was then compared between the two groups.
Primary outcomes of our study were short-term outcomes, including postoperative length of hospital stay and overall postoperative complication, as well as long-term outcomes and the three-year overall survival. Secondary outcomes were technical success, clinical success, and surgical characteristics.
All statistical analyses in this study were conducted using IBM SPSS version 22.0 (IBM Co., Armonk, NY, USA). Categorical variables were reported as frequencies and percentages. The chi-square test, or Fisher’s exact test, was used for comparisons between groups. Continuous variables were described using means and standard deviations if normally distributed and compared using an independent
A total of 210 patients diagnosed with malignant colon obstruction treated with SEMS placement (the SEMS group,
As summarized in Table
Comparison of variables between the SEMS group and ES group.
Variables | SEMS group ( | ES group ( | |
---|---|---|---|
Age (years)† | 73 (62–77) | 70 (60–80) | 0.867¶ |
Gender | 0.343 | ||
Male | 25 (75.8) | 33 (66.0) | |
Female | 8 (24.2) | 17 (34.0) | |
WIC | 4.1 (2.4) | 3.7 (2.4) | 0.433§ |
BMI | 22.4 (2.8) | 22.3 (3.6) | 0.946§ |
ASA (%) | 0.612 | ||
I | 1 (3.0) | 5 (10.0) | |
II | 22 (66.7) | 27 (54.0) | |
III | 9 (27.3) | 15 (30.0) | |
IV | 1 (3.0) | 3 (6.0) | |
Tumor location | 0.194 | ||
Ascending colon | 4 (12.1) | 16 (32.0) | |
Transverse colon | 2 (6.1) | 2 (4.0) | |
Descending colon | 10 (30.3) | 13 (26.0) | |
Sigmoid colon | 17 (51.5) | 19 (38.0) | |
Pathological stage | 0.627 | ||
I | 2 (6.1) | 2 (4.0) | |
II | 15 (45.4) | 21 (42.0) | |
III | 13 (39.4) | 25 (50.0) | |
IV | 3 (9.1) | 2 (4.0) | |
Differentiation degree | 0.309 | ||
Well-moderate | 31 (93.9) | 42 (84.0) | |
Poor-undifferentiation | 2 (6.1) | 8 (16.0) | |
Perineural invasion | 5 (15.2) | 8 (16.0) | 0.917 |
Vascular invasion | 8 (24.2) | 13 (26.0) | 0.857 |
Absolute neutrophil count (109/L)† | 4.4 (3.2–5.3) | 7.6 (5.5–9.8) | <0.001¶ |
HGB (g/L)† | 120.0 (107.5–134.5) | 131.5 (104.3–147.5) | 0.161¶ |
ALB (g/L)† | 36.5 (34.3–39.2) | 38.8 (34.1–43.3) | 0.163¶ |
CEA (ng/ml) | 17.2 (23.8) | 28.1 (67.9) | 0.376§ |
Time of stent placement (mins) | 88.8 (44.3) | — | — |
Values are presented as number (%).
The median interval from stent placement to elective surgery was 14 days (range, 7 to 34 days). The types of surgeries performed are summarized in Table
Types of surgeries performed.
Surgical type | SEMS group ( | ES group ( | |
---|---|---|---|
Left hemicolectomy | 10 | 13‡ | 0.668 |
Right hemicolectomy | 4 | 17§ | 0.025 |
Transverse colectomy | 2 | 1 | 0.712 |
Sigmoidectomy | 17† | 5 | <0.001 |
Hartmann’s procedure | 0 | 14¶ | 0.001 |
Values are presented as number.
Comparison of surgical characteristics and short-term outcomes between the SEMS group and ES group.
Outcomes | SEMS group ( | ES group ( | |
---|---|---|---|
Operative approach | <0.001 | ||
Laparoscopic | 24 (72.7) | 7 (14.0) | |
Open | 9 (27.3) | 43 (86.0) | |
Stoma needed | 0 (0) | 17 (34.0) | <0.001 |
Resection margin | 0.819 | ||
| 31 (93.9) | 45 (90.0) | |
| 2 (6.1) | 5 (10.0) | |
Length of surgery (mins) | 190.4 (60.6) | 209.5 (65.2) | 0.182‡ |
Blood loss (ml) | 210.6 (199.6) | 310.2 (213.3) | 0.036‡ |
Postoperative hospital stay (days) | 13.3 (10.1) | 18.5 (9.5) | 0.020‡ |
Overall postoperative morbidity | 9 (27.3)§ | 28 (56.0) | 0.010 |
Clavien–Dindo grade | |||
I | 1 (3.0) | 5 (10.0) | 0.443 |
II | 2 (6.1) | 4 (8.0) | 0.999 |
III | 1 (3.0) | 1 (2.0) | 0.999 |
IV | 4 (12.1) | 18 (36.0) | 0.016 |
V | 0 (0) | 4 (8) | 0.254 |
Values are presented as number (%) and
Since three patients initially referred for stenting were converted to the ES group due to technical failure, which could bias the results for short-term outcomes, we performed intention-to-treat (ITT) analysis as a sensitive analysis. The ITT showed that the SEMS group had a higher odds of minimally invasive surgery (
The mean follow-up time was 25.0 ± 17.1 months for the SEMS group, which was not significantly different from that of the ES group (25.2 ± 23.1 months,
Kaplan–Meier analysis. Between the SEMS group (blue line) and ES group (green line), there were no significant differences in three-year overall survival (
PP and ITT analyses in our study yield similar results that the SEMS, as a bridge to surgery, had a higher likelihood of minimally invasive surgery and a higher primary anastomosis rate and exhibited a favorable short-term outcome compared to emergency surgery due to a lower overall postoperative morbidity. In terms of long-term outcomes, the SEMS plus elective surgery did not lead to a significant improvement in 3-year survival compared with emergency surgery alone, based on PP and ITT analyses. As summarized in Table
Systematic reviews and meta-analyses on the topic of the SEMS as a bridge to surgery versus emergency surgery for malignant large bowel obstruction.
References | Study type | Study reviewed (number) | Population (SEMS : ES) | Object | Technical/clinical success rate (%) | Findings | |
---|---|---|---|---|---|---|---|
Significant difference | No significant difference | ||||||
Tan et al. [ | Meta-analysis | RCT (4) | 234 (116 : 118) | Left colon | 70.7/69.0 | SEMS: lower overall stoma rate, higher successful primary anastomosis rate | Postoperative mortality, primary anastomosis rate, permanent stoma rate, anastomotic leak rate, surgical site infection rate, 30-day reoperation rate |
Ye et al. [ | Meta-analysis | RCT (3), RS (5) | 444 (219 : 225) | Left colon | NA | SEMS: lower overall postoperative morbidity, lower temporary stoma rate | Postoperative mortality, permanent stoma rate, anastomotic leak rate, occurrence of abscesses rate, abdominal complications rate |
Zhang et al. [ | Meta-analysis | RCT (2), RS (6) | 601 (232 : 369) | Colon and rectum | 87.1/NA | SEMS: lower overall postoperative morbidity, lower overall stoma rate, higher primary anastomosis rate, lower anastomotic leakage rate, lower intensive care rate | Postoperative mortality, permanent stoma rate, overall survival |
Cirocchi et al. [ | Meta-analysis | RCT (3) | 197 (97 : 100) | Left colon and rectum | 62.9/52.5 | SEMS: lower overall stoma rate, higher primary anastomosis rate | Overall postoperative morbidity, postoperative mortality, permanent stoma rate, anastomotic leakage rate, intra-abdominal abscess rate, infections (wound, chest, urinary tract) rate |
De Ceglie et al. [ | Meta-analysis | RCT (5), RS (5), PS (3), CM (1) | 876 (405 : 471) | Left colon | 96.9/94.2 | SEMS: lower overall stoma rate, higher primary anastomosis rate, higher successful primary anastomosis rate, lower infection rate | Postoperative mortality, temporary stoma rate, anastomotic leakage rate, length of hospitalization, overall survival |
Zhao et al. [ | Meta-analysis | RCT (5) | 273 (136 : 137) | Left colon | NA | SEMS: lower overall postoperative morbidity, lower overall stoma rate, lower permanent stoma rate, lower surgical site infection rate | Postoperative mortality, primary anastomosis rate, anastomotic leak rate |
Huang et al. [ | Meta-analysis | RCT (7) | 382 (195 : 187) | Left colon | 76.9 | SEMS: lower overall postoperative morbidity, lower permanent stoma rate, higher primary anastomosis rate, lower wound infection rate | Postoperative mortality, anastomotic leakage rate, intra-abdominal infection rate |
Amelung et al. [ | Systematic review | RS (10), PS (4) | 2992 (2837 : 155) | Right colon | 95.5 | SEMS: lower postoperative mortality, lower major complication rate† | Overall postoperative morbidity, minor complication rate† |
Matsuda et al. [ | Meta-analysis | RCT (2), RS (7), PS (2) | 1136 (432 : 704) | Colon | NA | None | Overall survival, disease-free survival, recurrence rate |
Arezzo et al. [ | Meta-analysis | RCT (8) | 497 (251 : 246) | Left colon | NA | SEMS: lower overall postoperative morbidity, lower permanent stoma rate, lower temporary stoma rate, higher primary anastomosis rate | Postoperative mortality |
Wang et al. [ | Meta-analysis | RCT (9) | 594 (281 : 313) | Left colon | NA | SEMS: lower postoperative mortality, lower minor complications rate, higher primary anastomosis rate | Anastomotic leakage rate |
Amelung et al. [ | Meta-analysis | RCT (5), RS (12), PS (4) | 1919 (938 : 981) | Left colon | NA | SEMS: lower permanent stoma rate | Overall survival, disease-free survival, recurrence rate |
Foo et al. [ | Meta-analysis | RCT (7) | 448 (222 : 226) | Left colon | NA | SEMS: lower overall postoperative morbidity, higher recurrence rate | Postoperative mortality, overall survival, disease-free survival |
Boland et al. [ | Systematic review | RCT (7) | 408 (201 : 207) | Left colon and rectum | 81.1/76.1 | NA | NA |
Cao et al. [ | Meta-analysis | RCT (5), RS (16), PS (3) | 2580 (1302 : 1278) | Colon and rectum | NA | None | 3-year survival, 5-year survival, 3-year disease-free survival, 5-year disease-free survival, local recurrence rate, overall recurrence rate |
RCT, randomized clinical trial; RS, retrospective study; PS, prospective study; CM, case-matched; NA, not available.
There has been some concern with regards to short-term outcomes as to whether the SEMS can reduce overall postoperative mortality and morbidity. Although overall postoperative mortality did not differ significantly between the two groups (0% vs. 8%,
The incidence of general complications related to stent placement, such as perforation, migration, and reobstruction, was reported as 0–14.1%, 0.9–21.9%, and 0.5–40%, respectively [
The SEMS, as bridge to surgery for obstructive right colon cancer (ORCC), is also controversial approach. There were nine patients with ORCC in our study that were initially referred for stenting on account of their poor condition or willingness, while three of them were converted to emergency surgery due to technical failure. In our study, there was no significant difference in terms of short- and long-term outcomes between patients with ORCC in two groups based on PP and ITT analyses, which was similar to the results of a recent multicenter retrospective study [
The long-term outcome of the SEMS has always been the source of much scrutiny. Recent meta-analyses have reported no differences in the long-term oncological outcomes when comparing SEMS and ES patients [
There are some limitations to this study which need to be considered when interpreting our findings. Firstly, the patients were assigned to different management styles by attending surgeon or patient preference rather than randomization. This could result in selection bias because surgeons tended to choose a stent for the patients with poor condition, while patients preferred the emergency surgery due to economic considerations. Secondly, the data from this study were limited to what were recorded in the medical records in our institution. It is possible that patients received treatment (e.g., adjuvant chemotherapy) and follow-up care from other hospitals that we had no access to these data. In addition, the length of the follow-up period after surgical procedure might not be long enough to observe long-term survival outcomes for both groups. All patients were from a single health center in a metropolitan area. Therefore, our findings may not be generalized to other patient populations. A multicenter, longer, larger-scale randomized controlled study is needed to comprehensively compare the efficacy and short- and long-term outcomes between SEMS and ES procedures.
In conclusion, the results of our study showed that the SEMS, as a bridge to surgery for malignant colonic obstruction, was safe and feasible. Compared to emergency surgery, patients treated with stent-surgery exhibited significant short-term improvement and comparable long-term outcomes. We suggest that the SEMS, combined with elective surgery, is a promising alternative for patients with resectable malignant colon obstruction.
The data used to support the findings of this study are available from the corresponding author upon request.
The authors alone are responsible for the content and writing of this paper.
The authors declare that they have no conflicts of interest.