Patients characteristics
We examined 75 patients with MLBO whose background is shown in Table 1. The median age was 66 years old (range, 30–86 years). The male-female ratio was 48 men (64.0%) to 27 women (36.0%). In staging based on the UICC, there was 1 patient with Stage I, 26 (34.7%) patients with Stage II, 26 (34.7%) with Stage III, and 22 (29.3%) with Stage IV. Tumor location was significantly higher in the left-side colon and rectum (n = 59, 78.7%) than in the right-side colon (n = 16, 21.3%).
Table.1 Characteristics of the patients
BMI: Body mass index, ASA: American society of anesthesiologists, mGPS: modified Glasgow Prognostic Score, A: Ascending colon, T: Transverse colon, D: Descending colon S: Sigmoid colon, RS: Rectosigmoid colon, Ra: Rectum above the peritoneal reflection, Rb: Rectum below the peritoneal reflection, TSR: Technical success rate, CSR: Clinical success rate * Median (Min - Max)
The technical success rate of SEMS placement was 97.3%, and the clinical success rate was 96.0%. Two patients were confirmed to have suffered perforation during the procedure (perforation rate: 2.7%), and emergency surgery was performed on the same day. Stenosis of the SEMS occurred in one patient during the interval to surgery. Staging CT scans was given in all of above three cases before inserting SEMS and no synchronous malignancy was found. Except for these 3 patients, the remaining 72 patients showed improvement of obstructive symptoms, and it was possible to perform elective surgery without shifting to an emergency surgery during the follow-up period. Additionally, during BTS follow-up, synchronous multiple cancers were detected in 11 of the 75 patients (14.7%), of whom 4 required a change in procedure (Table 2). Table 3 shows the operative background. The median time from SEMS placement to surgery was 13 days (range, 0–62 days). A one-step anastomosis was performed in 73 patients (97.3%). The rate of Clavien-Dindo grade II or higher complications was 28.0% (n = 21) and that of grade III or higher was 16.0% (n = 12). Although 7 patients suffered anastomotic leakage, all improved with conservative treatment, and none required reoperation.
Table.2 Synchronous cancers among the MLBO patients
C: Cecum, A: Ascending colon, T: Transverse colon, D: Descending colon S: Sigmoid colon, RS: Rectosigmoid colon, Ra: Rectum above the peritoneal reflection, Rb: Rectum below the peritoneal reflection, FAP: Familial adenomatous polyposis, ESD: Endoscopic submucosal dissection
Table.3 Perioperative features
Characteristics
|
|
N=75
|
Period to surgery (day)*
|
|
13 (0 - 62)
|
Aproach of Surgery (%)
|
Open
|
21 (28.0)
|
|
Lap
|
54 (72.0)
|
Tumor size (mm)*
|
|
65 (40 - 112)
|
Lymph node dissection*
|
|
25 (7 - 102)
|
Blood loss (ml)*
|
|
30 (0 - 4850)
|
Operation Time (min)*
|
|
247 (127 - 812)
|
Postoperative complication
(Clavien-Dindo) (%)
|
Grade II
|
9 (12.0)
|
Grade IIIa
|
12 (16.0)
|
|
Grade ≥IIIb
|
0
|
Postoperative stay (day)*
|
|
13 (8 - 54)
|
* Median (Min - Max)
Open Surgery Versus Laparoscopic Surgery
Patient background and operative factors of the 21 patients (28.0%) in the open surgery (Open) group and the 54 (72.0%) patients in the laparoscopic surgery (Lap) group can be compared in Table 4. There were significantly more T4 cases in the Open group. Operation time was 199 min in the Open group and 252.5 min in the Lap group (p = 0.49), and blood loss was 210 mL in the Open group and 30 mL in the Lap group (p = 0.0017). Postoperative complications of Clavien-Dindo classification Grade III or higher were observed in 5 patients (23.8%) in the Open group and in 17 (13.0%) patients in the Lap group. Although anastomotic leakage occurred in 5 patients in the Lap group, none of the patients was classified as Clavien-Dindo 3b or higher.
Table.4 Characteristics of the patients, open surgery group(open) versus laparoscopic surgery group (Lap)
|
|
Open (N=21)
|
Lap (N=54)
|
p value**
|
Sex (%)
|
M
|
15 (71.4)
|
33 (61.1)
|
0.40
|
|
F
|
6 (28.6
|
21 (38.9)
|
Age*
|
|
68.0 (50-86)
|
63.5 (30-82)
|
0.061
|
BMI*
|
|
19.7 (16.7-28.0)
|
21.3 (14.4-34.9)
|
0.73
|
ASA (%)
|
1
|
4 (19.0)
|
21 (38.9)
|
0.17
|
|
2-3
|
17 (81.0)
|
33 (61.1)
|
mGPS (%)
|
0
|
9 (42.9)
|
37 (68.5)
|
0.021
|
|
1-2
|
12 (57.1)
|
16 (29.6)
|
T (%)
|
2
|
0 (0)
|
1 (1.9)
|
0.042
|
|
3
|
8 (38.1)
|
32 (59.3)
|
|
4a
|
8 (38.1)
|
18 (33.3)
|
|
4b
|
5 (23.8)
|
3 (5.6)
|
N (%)
|
0
|
10 (47.6)
|
20 (37.0)
|
0.37
|
|
1
|
4 (19.0)
|
19 (35.2)
|
|
2
|
7 (33.3)
|
15 (27.8)
|
Stage (%)
|
I
|
0 (0)
|
1 (1.9)
|
0.23
|
|
II
|
8 (38.1)
|
18 (33.3)
|
|
III
|
5 (23.8)
|
20 (37.0)
|
|
IV
|
8 (38.1)
|
14 (25.9)
|
Location (%)
|
Right
|
6 (28.6)
|
10 (18.5)
|
0.35
|
|
Left
|
15 (71.4)
|
44 (81.5)
|
Size (mm)*
|
65.0 (40-108)
|
61.5 (0-615)
|
0.36
|
Operation time (min)*
|
199 (127-610)
|
252.5 (137-812)
|
0.49
|
Blood loss (ml)*
|
210 (40-4850)
|
30 (5-615)
|
0.0017
|
Lymph node dissection*
|
25 (7-72)
|
25 (8-102)
|
0.62
|
Postoperative stay (day)*
|
14 (8-54)
|
13 (8-47)
|
0.60
|
Postoperative complication Clavien-Dindo ≥Grade III (%)
|
5 (23.8)
|
7 (13.0)
|
0.26
|
Anastomotic leakage
|
2
|
5
|
|
SSI
|
2
|
0
|
|
Ileus
|
1
|
2
|
|
BMI: Body mass index, ASA: American society of anesthesiologists,
mGPS: modified Glasgow Prognostic Score
* Median (Min - Max), ** chi-squared test
Os And Rfs
Most cases of MLBO are advanced, having a depth of wall invasion deeper than T3, with vascular invasion and positive lymph nodes [7, 21, 22]. There are also some reports that 25% of MLBOs are diagnosed as Stage IV, which indicates distant metastases [7]. There is also a report that the long-term prognosis is equivalent to non-obstructed cases when compared by stage [23], but even in the same stage, many cases of MLBO are reported to be advanced cases and to have poorer prognosis [24]. Therefore, patients with stage II MLBO are considered the so-called high-risk group, for which postoperative adjuvant chemotherapy is recommended in the guidelines.
In this retrospective study, we examined the short- and long-term prognoses of MLBO to verify the effectiveness and safety of the BTS strategy using SEMS. Although no direct comparison with emergency surgery was made in this study, no significant difference in either short-term or long-term prognosis of colorectal cancers has been reported in the past. Furthermore, the BTS strategy secures time for systemic examination such as for the presence of multiple cancers. Therefore, we consider SEMS placement to be an effective treatment strategy for MLBO.
At present, there is no consensus on the effectiveness of SEMS for BTS in MLBO. The ESGE guidelines show that although SEMS is superior in terms of stoma construction, initial anastomosis rate, and complication rate, stent placement for the purpose of BST in left-side colorectal cancer is not recommended as a standard treatment [14]. The main reasons are the high perforation rate due to stent placement, the lower 5-year survival rate, and the high local recurrence rate. The large study on which this guideline was based reported a technical success rate of 76.9% and a rate of perforation due to SEMS placement of as high as 8.7% [14]. As perforation is reported to be one of the risks of peritoneal dissemination and a poor prognostic factor [24], the success rate of SEMS placement would seem to affect the long-term prognosis. The success rates shown in the cohort studies conducted in Japan were 98–99% with low perforation rates of 0–2%. In the present study as well, only 2 of the 75 patients suffered perforation, and the technical success rate was high at 97.3%, which indicates that SEMS placement could be safely performed. In addition, there is a report that mechanical compression of a tumor with a metallic stent induces perineural invasion and stimulates cancer cells to promote tumor growth and metastasis [26], whereas other reports found no significant difference in perineural invasion compared with a transanal tube. Another report concluded that mechanical compression of the tumor rather decreased the proliferative capacity [27]. Therefore, the effect of metallic stents on long-term prognosis still remains controversial and an important topic. A multicenter randomized controlled trial (COBRA trial) is currently underway in Japan to establish its own evidence. In our institution, SEMS is widely used as a BTS for MLBO on the basis of these results. However, as shown in the schema, due to reasons of securing the margin for resection and the pain involved after insertion, a transanal ileus tube or emergency surgery is rather recommended for lower rectal cancers (Table 5). The indication of the laparoscopic approach is also problematic in advanced cases of MLBO after SEMS placement. While some reports showed the feasibility and safety of laparoscopic surgery after SEMS placement with no transition to open surgery and fewer complications, no reports suggested for long-term prognosis [28, 29]. We also compared laparoscopic surgery and open surgery in this study.
In recent years, the development of surgical devices and endoscopic surgical techniques has led to the widespread use of laparoscopic surgery even for advanced colorectal cancers. However, there is no consensus on a surgical approach for MLBO, especially with colonic stent placement. Law et al [28] compared short-term treatment after colonic stent placement between open and laparoscopic surgery groups and found that the postoperative hospital stay was shorter and the incidence of postoperative complications was lower in the laparoscopic surgery group. Other reports on BTS also showed that laparoscopic surgery tended to be performed on patients in whom effective decompression was achieved [29]. In the early stage of BTS, we performed the operation by laparotomy, but laparoscopic surgery has gradually increased over time and is presently the first choice. However, we still perform laparotomy in patients with T4b cancer.
Although the incidence of anastomotic leakage was somewhat high in the Lap group in the present study, there was no complication higher than Clavien-Dindo grade 3b that required reoperation. For this reason, left-sided colorectal cases (including RS, Ra, Rb) tended to be included in the Lap group.
Regarding long-term prognosis in the study patients, 3-year OS was over 80% for all stages, and there was no significant difference between open and laparoscopic surgery. These results suggest that the combination of SEMS placement with laparoscopic surgery may be a feasible and safe treatment.
In patients with colorectal cancer, the prevalence of synchronous cancers ranges from 0.7% to about 7% [30, 31]. However, synchronous multiple cancers were detected in 14.7% of patients in our institution. Therefore, we perform total colonoscopy including the oral side of the primary tumor in our institution before performing BTS to avoid an unnecessary second colorectal resection.
As the limitations, this is a retrospective, single-arm study and should better to be compared by factors such as tumor localization and postoperative treatment which may affect RFS and OS. Moreover, since this study does not compare the primary anastomosis case with the stoma construction case, it is difficult to concluded that the stoma construction can be safely avoided.
The rate of 3-year OS (median follow-up months) was 100% (60.0) for Stage I, 87.1% (30.5) for Stage II, 77.1% (28.5) for Stage III, and 33.1% (24.0) for Stage IV cancer (Fig. 1a). That of 3-year RFS was 100% (60) for Stage I, 79.6% (24.0) for Stage II, and 71.6% (21.5) for Stage III cancer (Fig. 1b). When compared by surgical approach, the 3-year OS rate was 66.4% for the Lap group and 67.5% for the Open group (p = 0.56). The 3-year RFS rate was 82.2% for the Lap group and 62.5% for the Open group (p = 0.11). Although the difference was not statistically significant, the prognosis was relatively better in the Lap group (Fig. 2).