The results are hereby presented separately as O (obstruction) and P (perforation) when required; otherwise, the statements can be considered valid for both conditions.
Management of obstruction: left colon (from the distal transverse colon to the anus)
Several options to manage obstructive left colon cancer (OLCC) are available (see Table
4 and
Appendix 3).
Table 4
Treatment options for OLCC
Loop colostomy (C) (bridge to resection or palliation) | | |
Primary resection with end colostomy: Hartmann’s procedure (HP) | | |
Resection and primary anastomosis (RPA) | Total/subtotal colectomy (TC) | Intraoperative colonic irrigation (ICI) Manual decompression (MD) Covering stoma |
Segmental colectomy (SC) |
Tube decompression | | |
Endoscopic colonic stenting by self-expanding metallic stents (SEMS) | Bridge to surgery | |
Palliation |
Statement 3.1: Loop colostomy (C) versus Hartmann’s procedure (HP)
Hartmann’s procedure should be preferred to simple colostomy, since colostomy appears to be associated with longer overall hospital stay and need for multiple operations, without a reduction in perioperative morbidity LoE 2, GoR B.
Loop colostomy should be reserved to unresectable tumours (if SEMS is not feasible), for severely ill patients who are too unfit for major surgical procedures or general anaesthesia.
A stoma provides colonic decompression with minimal surgical trauma, reduces the risk of contamination from an unprepared bowel and allows an intensive resuscitation of the patient and a better staging prior to the definitive treatment.
However, Fielding et al. [
46] did not find any differences in the mortality rate between 47 patients treated with loop colostomy and 90 patients who received a primary resection.
A RCT [
47] between Hartmann’s procedure (63 patients) and colostomy (58 patients) found no difference in terms of mortality and morbidity rate, recurrence rate and cancer-specific survival between the two surgical approaches. On the other hand, the overall length of hospital stay was shorter in the primary resection (35 days) than in the staged resection group (49 days) (
p = 0.01).
A Cochrane systematic review [
48] considered only other four retrospective cases series and no RCT; therefore, a meta-analysis could not be performed.
Since then, another RCT was published [
49]; the authors found a similar impact on mortality and hospitalisation with both surgical techniques.
Statement 3.2: Hartmann’s procedure (HP) versus resection and primary anastomosis (RPA)
RPA should be the preferred option for uncomplicated malignant left-sided large bowel obstruction in absence of other risk factors.
Patients with high surgical risk are better managed with HP. LoE 3-GoR B.
HP remains one of the most common procedures in emergency surgery of the left colon [
50‐
52]. However, the historical concept that a completely clear colon is necessary to avoid AL [
53] has been questioned by others [
54,
55], and there is now good evidence supporting that the presence of faeces in the large bowel does not influence the rate of anastomotic dehiscence, [
56,
57] nor its severity [
58].
In recent years, there has been an increasing trend toward a one-stage resection for left-sided obstruction, but unfortunately, no RCTs were conducted comparing HP and RPA; therefore, neither grade A nor B evidence are available, and the choice generally depends on the individual surgeon’s judgement.
The first major report regarding RPA for obstructive cancer came from the Large Bowel Cancer Project (LBCP). The authors reported a mortality of 35% for staged resections and of only 14% for primary resection [
46].
Since then, many prospective and retrospective series on RPA in OLCC reported rates of anastomotic dehiscence ranging from 2.2 to 12% [
59‐
65]; these results are almost comparable to the 2–8% rate after elective surgery [
56,
57,
66,
67].
Meyer et al. [
51] reached different conclusions: they compared HP and RPA performed for OLCC both with curative and palliative intent. Despite the significantly higher preoperative risk within the HP group, postoperative mortality rate was lower as compared to the RPA group, both for curative (7.5 versus 9.2%;
p value reported as not significant) and palliative procedures (33 versus 39%;
p value reported as not significant). The limit of this study was the high number of participating institutions (309), which were also very heterogeneous in terms of intensity of care, spanning from regional to university hospitals.
The main advantage of RPA is to avoid a second major operation, which is associated to a morbidity rate of 20–50% and a dehiscence rate of 2–7% [
68‐
72].
Furthermore, it should be considered that the majority of stomas (up to 90%) created during HP for CRC do not get reversed, due to necessity of adjuvant treatment and/or disease progression [
62,
73].
In favour of RPA, it has also been postulated that this choice may result in long-term survival benefits, although evidence on this aspect is weak [
65].
These unquestionable advantages of RPA must be counterbalanced by the potentially catastrophic situation resulting from AL in a fragile patient. For this reason, many parameters, related to both the surgeon and the patient, should be taken into account before deciding to perform a colo-colonic or colo-rectal anastomosis [
63,
64,
74]. Historically, two main elements prevent anastomotic dehiscence: a tension-free anastomosis and good blood supply to the anastomotic rim; despite the single surgeon’s experience may play a pivotal role in the evaluation of these parameters, evidence exists regarding the validity of the assessment of the anastomotic blood supply using intraoperative near-infrared indocyanine green [
75,
76]. Risk stratification is the cornerstone of patient’s selection. The Association of Coloproctology of Great Britain and Ireland (ACPGBI) identified four important predictors of outcome—age, ASA grade, operative urgency, and Dukes’ stage [
64]; others showed similar results [
63,
74].
The experience and subspecialty of the surgeon also seem to be important factors in surgical decision. It has been demonstrated that primary anastomosis is more likely to be performed by colorectal rather than general surgeons, and by consultants rather than unsupervised trainees, with lower rate of anastomotic dehiscence and mortality [
46,
74,
77‐
80].
Keeping in mind these considerations, HP could be more appropriate for patients deemed to be at high risk and when they are managed in an emergency setting by unspecialised surgeons.
Statement 3.3: RPA: the role of diverting stoma
There is no evidence supporting that a covering stoma can reduce the risk of anastomotic leak and its severity. LoE 4-GoR C
Unfortunately, there are very few data and no RCT comparing the use of diverting stoma versus no use of diverting stoma after surgery for OLCC; therefore, very weak recommendations can be drawn.
Kube et al. [
81] analysed the results of 743 patients who underwent emergency radical surgery for OLCC. Of these, 30% had HP, 58% RPA and 12% RPA and covering stoma.
The morbidity and hospital mortality did not differ significantly between the groups, and the addition of a protective stoma did not affect the rate of anastomotic dehiscence (7 and 8% respectively), or the rate of re-operation (5.6 versus 5.7%).
We may postulate that a protective stoma does not reduce the rate of AL, but the rate of AL requiring re-operation [
82]. A leak originating from an intraperitoneal anastomosis is likely to cause diffuse peritonitis and therefore mandates a reoperation. For this reason, the role of diverting stoma after resection and primary anastomosis for OLCC seems limited.
Statement 3.4: Total colectomy versus segmental colectomy
In absence of caecal tears/perforation, evidence of bowel ischemia or synchronous right colonic cancers, total colectomy should not be preferred to segmental colectomy, since it does not reduce morbidity and mortality and is associated with higher rates of impaired bowel function. LoE 2, GoR B.
Total colectomy (TC) with ileo-rectal anastomosis was proposed as an alternative procedure to avoid a stoma and at the same time to overcome the problems related to a distended unprepared colon [
83‐
85]. This operation has an absolute indication when obstruction has determined a right colonic ischemia, caecal tears or perforation, or when synchronous proximal malignant tumours are present [
21].
Major disadvantages of TC are represented by a technically challenging procedure, prolonged operative time and poor functional results, with many patients complaining of diarrhoea and possibly developing electrolyte disturbances [
84,
86].
A single RCT, the SCOTIA (Subtotal Colectomy versus On-Table Irrigation and Anastomosis) trial was published [
86]; 91 patients from 12 different centres were randomised to total/subtotal colectomy (47 patients) versus segmental colectomy with on-table lavage (44 patients). The authors found no differences in terms of morbidity and mortality, but significantly worse functional results after TC.
Statement 3.5: Intraoperative colonic irrigation (ICI) versus manual decompression (MD)
ICI and MD are associated with similar mortality/morbidity rate. The only significant difference is that MD is a shorter and simpler procedure. Either procedure could be performed, depending on the experience/preference of the surgeon. LoE 2-GoR B
There was only a RCT that compared ICI (24 patients) with MD (25 patients) in OLCC [
87]. They concluded that MD is shorter and simpler than ICI and offers similar results in terms of mortality, morbidity and AL rates. However, the power of this study was low.
A systematic review published in 2009, which included the above-mentioned RCT, one prospective comparative trial and 5 prospective descriptive case series, concluded that, although the power of the studies was poor and a large-scale prospective randomised trial is desirable, no statistical significance could be shown between the two procedures [
88].
Statement 3.6: RPA: the role of laparoscopy
The use of laparoscopy in the emergency treatment of OLCC cannot be recommended and should be reserved to selected favourable cases and in specialised centers.
LoE 4-GoR C
Traditionally, CO has been considered an absolute contraindication to laparoscopy, because of the high-risk patient profile and the level of operative technical difficulties due to dilated and vulnerable bowel [
89].
However, with the diffusion of colo-rectal laparoscopy and increasing experience, some limited series became available with favourable results [
90,
91], but no randomised trials have been produced.
Ballian et al. [
92] evaluated the role of laparoscopy for emergency restorative colectomy using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database. They found that less than 10% of patients with OLCC were managed laparoscopically with colon resection and primary anastomosis, with comparable rates of morbidity and mortality, but faster recovery.
A systematic review published in 2014 analysed the results of 47 studies on laparoscopy in emergency colorectal surgery, but most of them regarded acute presentation of IBD or diverticular disease, while only a small number presented data on OLCC [
93].
Statement 3.7: Tube decompression (TD)
TD can be a valid alternative option as BTS for high-risk OLCC. LoE 4-GoR C
Transanal TD is a minimally invasive endoscopic procedure that may allow the decompression of an obstructed colon in order to safely delay elective surgery with RPA. Despite the appeal for this bridge to surgery technique, unfortunately only few data is available.
Efficacy and safety of TD have been reported [
94‐
102], with 80 to 100% rate of technical success and 72.5 to 100% rate of clinical success. Complications, such as perforation, are infrequent (incidence ranging from 0 to 10%) and may be caused by the pressure of the tip of the tube against the colonic wall.
However, there is lack of trial-based evidence to confirm the usefulness of TD and its efficacy in terms of short- and long-term outcomes.
Theoretically, TD has some advantages over self-expandable metallic stent (SEMS): the colon can be cleaned by lavage through the tube; tumour manipulation is minor and costs are contained. However, there are no randomised trials but only one retrospective study that compared these two techniques and did not show significant differences [
103].
Despite these results appear promising, the available level of evidence is suboptimal, and therefore, no conclusions can be drawn.
Statement 3.8: Palliation: SEMS versus colostomy
In facilities with capability for stent placement, SEMS should be preferred to colostomy for palliation of OLCC since it is associated with similar mortality/morbidity rates and shorter hospital stay. LoE 1-GoR A
Alternative treatments to SEMS should be considered in patients eligible to a bevacizumab-based therapy. Involvement of the oncologist in the decision is strongly recommended. LoE 3-GoR B
Endoscopic stent placement was initially introduced in the palliative treatment of obstructive rectal [
104] or recto-sigmoid cancer [
105].
The development of SEMS, which can be introduced through a colonoscope, allowed to extend their use to a range of scenarios of CO [
106,
107], not only with palliative intent to avoid a stoma, but also with the aim of transforming an emergency surgical operation into an elective procedure, and od reducing morbidity, mortality and stoma rate [
108].
Several RCTs, case-matched studies and retrospective series have been published, but results are controversial.
We found five RCT comparing colostomy versus SEMS for palliation of malignant CO [
109‐
112]; one of them was an update of a previous RCT [
113].
Xinopoulos et al. [
109] randomised 30 patients. A stent was successfully placed in 14/15 (93.3%) randomised to stenting, and CO was permanently resolved in eight of them (57%). There was no mortality related to the procedure in both groups. Mean survival was 21.4 months in SEMS group and 20.9 months in C group. Mean hospital stay was significantly higher in C group, and costs were comparable. The authors concluded that SEMS placement represents a good alternative to colostomy, providing a better quality of life for the patient, without the psychological repercussions of a colostomy, and it appears to be cost-effective.
Fiori et al. [
110] randomised 22 patients: in both groups, the mortality was 0% and the morbidity was similar. SEMS group had shorter time to oral intake, restoration of bowel function, and hospital stay.
Some years later, the same group published the long-term results [
113]: mean survival was 297 days (125–612) with SEMS and 280 days (135–591) in patients with stomas (
p = n.s.). There was no mortality related to the procedures. Patients with stomas found them unacceptable, and the same feelings were present in their family members. On the contrary, none of the patients with stents or their family members reported any inconveniences related to the procedure.
The Dutch Stent-in I multicenter RCT [
111] was terminated prematurely after enrolling 21 patients; the decision was taken after the incidence of four stent-related perforations among 10 patients enrolled for SEMS (in particular occurring12, 12, 44 and 106 days after stent placement), resulting in three fatal events.
No clear explanation for such a high perforation rate was retrieved; the authors suggested that changes made in the design of the stents (WallFlex, Boston Scientific Natick, MA), which have a larger diameter of the proximal end (30 mm) and are made of braided nitinol instead of stainless steel, might have had a role in the aetiology of the perforation. However, other subsequent series in which the Wallflex stent was used reported a perforation rate of around 5% [
114‐
116], which is in line with commonly observed figures with other SEMS [
116].
A more recent RCT [
112] enrolled 26 patients in the SEMS group and 26 in the surgery group, with the primary aim to assess the quality of life through a validated questionnaire. Stent insertion was successful in 19 cases (73%), while the remaining patients required a stoma. There were no stent-related perforations. The SEMS group had significantly reduced procedure time (
p = 0.014) and post-procedure stay (
p = 0.027). Thirty-day mortality was 8% in the SEMS group and 15% in the surgery group (
p = 0.668). There was no difference in median survival (5.2 versus 5.5 months), but the surgery group had significantly reduced quality of life.
Several meta-analyses [
117‐
120], pooling data from RCT and from prospective non-randomised or retrospective studies, showed results in favour of stent placement.
According to the available RCTs [
109,
112,
113], palliation with the use of SEMS could affect the OS indirectly, by increasing the risk of local complications, such as tumour site perforation, and therefore requiring the interruption of chemotherapy [
118,
119].
A correlation between chemotherapy with bevacizumab and stent-related perforation has been noticed [
116,
121].
A recent meta-analysis, including 4086 patients from 86 studies, confirmed an increased risk of perforation in patients with bevacizumab treatment, as compared to absence of concomitant chemotherapy (12.5 versus 9.0%) [
122].
For this specific reason, the recently published European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guidelines do not recommend the use of SEMS in patients who are being treated with or are expected to be commenced on antiangiogenic drugs [
123].
Statement 3.9: Bridge to surgery: SEMS and planned surgery versus emergency surgery.
SEMS as bridge to elective surgery offers a better short-term outcome than direct emergency surgery. The complications are comparable, but the stoma rate is significantly smaller. LoE 1-GoR A
Long-term outcomes appear comparable, but evidence remains suboptimal; further studies are necessary.
For these reasons, SEMS as BTS cannot be considered the treatment of choice in the management of OLCC, whilst it may represent a valid option in selected cases and in tertiary referral hospitals. LoE 1-GoR B
SEMS as BTS allows timely resolution of the obstruction before definitive surgical treatment, giving the possibility of an elective surgical procedure.
For this reason, soon after the introduction of the new devices [
105,
124], BTS with SEMS has been considered a pivotal change in the management of colonic obstruction [
106] and has been rapidly implemented in clinical practice, although solid scientific evidences were still missing.
In 2012, Zhang et al. [
125] performed a meta-analysis of eight studies, including six retrospective studies. Pooled data showed impressive results in favour of stent placement.
These extremely favourable results, however, were not confirmed by other studies, which reported a worrisome trend towards a stent-driven enhanced risk of oncologic recurrence [
126‐
128].
When adjunctive results from randomised controlled trials became available, the overall efficacy of BTS with SEMS appeared to be less definite than previously reported.
Considering a total of seven trials [
111,
129‐
134], three were prematurely terminated for the following reasons: very high morbidity rate in the SEMS BTS group [
111], very high morbidity rate in the ES group[
130] and high technical failure rate with SEMS [
131], respectively.
Summarising the results of these trials, the following main findings arise.
Firstly, the rate of clinical success, which was originally reported to be over 90%, dropped to a mean of around 70%. Secondly, short-term results (in particular postoperative morbidity and mortality, length of hospital stay) appeared comparable between ES and BTS with SEMS. This was also confirmed by the most recently published RCT [
134]. The trial was designed to recognise a 20% decrease in morbidity in the stent group as compared to the ES group, but in fact, complications occurred in 51.8% of SEMS group patients and 57.6% of direct surgery group (
p = 0.5).
On the other hand, all the RCTs have shown that the use of SEMS is related to a reduction in the rate of stomas.
Moreover, the use of SEMS increments the odds of laparoscopic resection. The so-called endo-laparoscopic approach consists in endoscopic stent followed by laparoscopic elective surgery [
129,
135,
136].
In the RCT by Cheung et al. [
129], all patients undergoing direct surgery had an open approach, while 60% of patients in the SEMS group were managed laparoscopically.
All these considerations have been confirmed by comprehensive data from different meta-analyses [
137‐
143] it can therefore be affirmed that SEMS as BTS provides better short-term outcomes than direct ES.
The oncologic issues related to this approach remain uncertain, and this represents a relevant field of future research.
Analysis of available data from RCT considering long-term outcomes [
130,
133,
134,
144,
145] does not show significant harmful effects in OS with SEMS use; however, three of them [
130,
133,
145] have reported a tendency towards a diminished disease-free survival (DFS). In particular, Alcantara et al. [
130]reported a rate of recurrence as high as 53.3% (8/15) after SEMS versus 15.4% (2/13) after ES.
Moreover, a recent case-control study suggested that SEMS placement might have a critical negative impact on the tumour anatomical site; the authors noticed a significantly higher percentage of tumour ulceration, perineural invasion and lymph node invasion in the SEMS group as compared to the surgery-only group [
126].
The main problem related to a potential augmented risk of recurrence after SEMS is the risk of perforation, which is reported in up to 13% of cases. In addition, Pirlet et al. described a peculiar analysis on postoperative pathology, showing that an undetected perforation was present in almost 27% of SEMS [
131]. Risk of perforation constitutes a major concern, as underlined by a post hoc analysis of one RCT, in which the 4-year DFS rate was 0% in patients with a stent-related perforation, versus 45% in patients without perforation [
145].
Although worrisome to a certain extent, these results come from studies with small number of patients and with an overall short follow-up time to guide definitive conclusions.
Matsuda et al. performed a meta-analysis to specifically investigate the long-term outcomes of SEMS [
142]: 11 studies were included, with a total of 1136 patients, but only two of them were RCT, while two were prospective series and seven retrospective.
OS was reported in all studies (3-year OS in 3 of them), while DFS and recurrence in six and eight studies, respectively. Pooled data showed no significant difference between SEMS as a BTS and ES groups neither in OS (RR = 0.95; 95% CI 0.75–1.21; p = 0.66), nor in DFS (RR = 1.06; 95% CI = 0.91–1.24; p = 0.43) and recurrence rate (RR = 1.13; 95% CI 0.82–1.54; p = 0.46).
Similar results were presented in the meta-analysis from Ceresoli et al. [
146]. Seventeen studies (5 RCTs, 3 prospective and 9 retrospective comparative cohort studies), for a total of 1333 patients, were included in the analysis. No significant differences were noticed in recurrence rate (RR = 1.11 95% CI 0.84–1.47,
p = 0.47), 3-year mortality (RR = 0.90 95% CI 0.73–1.12,
p = 0.34) and 5-year mortality (RR = 1.00 95% CI 0.82–1.22,
p = 0.99). No differences were found among randomised and observational studies.
As stated by the authors, both these meta-analyses have a great limitation related to the quality of the considered studies: none of the included studies was designed for long-term follow-up, median follow-up times were generally short and heterogeneous and survival rates were estimated with the Kaplan–Meier method rather than with observed events.
For these reasons, although encouraging, these results must be considered with extreme caution. A “non-inferiority” RCT with survival as primary end point would be the appropriate method to correctly investigate long-term outcomes after SEMS as BTS versus ES.
Statement 3.10: Extraperitoneal rectal cancer.
Locally advanced rectal cancers are better treated with a multimodal approach including neoadjuvant chemoradiotherapy. LoE 1-GoR A
In case of acute obstruction, resection of the primary tumour should be avoided and a stoma should be fashioned, in order to permit a correct staging and a more appropriate oncologic treatment.
Transverse colostomy seems to be the best option, but other modalities can be considered. SEMS is not indicated.
Extraperitoneal rectal cancers have particular features, which deeply influence the management of obstructive disease.
It has to be considered that a rectal cancer producing an obstruction invariably represents a locally advanced disease. For this reason, if curative resection is judged to be possible, elective surgery should be preceded by neoadjuvant chemotherapeutic treatment [
147‐
150]. The direct consequence of this consideration is that, in case of obstructive emergency, the surgical procedure of choice has to be restricted to techniques aiming to solve the obstruction and to permit a timely initiation of multimodal therapies. Furthermore, the surgical procedure should provide a long-term solution, allowing to conduct the patient through the entire duration of neoadjuvant treatment, until the execution of definitive surgery, and avoiding interferences with the therapeutic schedules and final oncologic result.
No comparative studies between endoscopic stenting and faecal diversion are available.
However, use of SEMS in low rectal cancer has been linked to chronic pain and tenesmus [
102] and a consequential worsening of quality of life. Radiation and chemotherapy, determining tumour necrosis and shrinkage, may favour the development of complications such as migration and perforation that might compromise the final oncologic results.
Moreover, it should be considered that a stoma will be fashioned in any case at the time of surgical resection, either in the case of abdominal-perineal resection or in the case of low anterior resection, where a diverting temporary stoma is highly recommended [
151‐
153].
All these being considered, it is always preferable to manage rectal obstruction with a stoma; the surgeon should plan the future surgical resection and choose the stoma type and location accordingly.
In essence, and in an ideal situation, the type and location of the emergency stomas should correspond to the type and location of future diverting or definitive stoma.
Previous studies [
151,
154,
155] and a recent meta-analysis [
156] of trials comparing loop ileostomy versus loop colostomy after elective anterior resection showed better results after loop ileostomy.
Despite this, in case of an emergency rectal obstruction and a planned future anastomosis, a loop ileostomy is a viable option only if the obstruction is incomplete or the ileocaecal valve is patent; otherwise, colonic distension would not be solved. In presence of a complete obstruction and a competent ileocaecal valve, a colostomy is mandatory. Scientific evidence to guide the choice of type a location of the emergency colostomy is limited.
As stated above, the choice of type (end or loop) and site (transverse versus sigmoid colon) of colostomy should be tailored on the individual patient considering the planned definitive treatment.
Limited to patients at high risk for general anaesthesia, a loop left side colostomy could be fashioned under local anaesthesia and intravenous sedation via left side skin incision (the so-called trephine stoma) [
157].
A widely used practical approach consists in a right-sided loop transverse colostomy. This is preferred over a sigmoid colostomy because it can be left in place to protect the anastomosis after the planned surgical resection, it is easier to be fashioned due to the mobility of the transverse colon, it avoids the risk of damage to the marginal arcade and it does not alter the left abdominal region in case a permanent end colostomy becomes necessary at the time of definitive surgical resection. When an abdominal-perineal resection is predictable, an end sigmoid colostomy could be a valid alternative [
158].