Minimally Invasive Methods of Temporary Decompression of the Colon with Obturation Colonic Obstruction: a Literature Review

Colorectal cancer is one of the most common oncological diseases. In 40–60% of cases, patients with colorectal cancer enter general surgical hospitals with complications. Obstructive colonic obstruction is the most common complication of colorectal cancer. The radical operation against the background of colonic obstruction is associated with a high postoperative lethality, ranging from 5% to 34%. To improve the results of surgical treatment of patients with colorectal cancer complicated by obturation colonic obstruction, various minimally invasive methods of temporary decompression have been proposed, followed by radical surgery, which significantly reduce the risk of complications and mortality.

Colorectal cancer is one of the most common cancers [1].In Russia, colorectal cancer occupies the 3 rd place (11.3%) in the structure of cancer incidence.The average age of patients with an established diagnosis of colon cancer is 68.1 years (66.9 years for men and 69.0 years for women) [2].
Thus, to reduce the frequency of complications and mortality in this category of patients, it seems promising and quite reasonable to resolve acute obstruction of the colon and transfer emergency surgery to delayed or planned.
Two-stage operations (by type of Hartmann's operation) are currently the most widespread in connection with radicalism, the rapid resolution of intestinal obstruction, the lack of risk of anastomotic failure and the possibility of mastering the operation by young surgeons.However, patients are forced to live with the presence of colostomy, which significantly reduces their adaptation in the social environment.The terms of repeated reconstructive operations for closing a colostomy are from 1 to 24 months [21][22][23], and in 40-70% of cases the recovery phase of the operation cannot be performed [24,25].
Among single-stage operations with removal of the tumor and restoration of the continuity of the colon, two options of interventions are most often used: 1. Subtotal colectomy with ileosigmoid/ileorectal anastomosis; 2. Segmental resection of the colon with its intraoperative mechanical preparation.Each of these operations has a number of advantages and disadvantages.
Studies have shown that during the subtotal colectomy in patients with obturation colonic obstruction, a lower incidence of suture failure is observed during the formation of the ileocolonic anastomosis, which is 10% less than during the formation of colocolonic anastomosis formed during segmental resection of the colon, where the incidence of sutures failure reaches 18-20% [26].Another advantage of subtotal colectomy compared to segmental resection of the colon with the conduction of a primary anastomosis is the radical removal of an unprepared, overstretched segment of the intestine, which may include areas of ischemic damage or contain synchronous tumors not detected during the surgery.At the same time, the consequence of a radical removal of the colon is the development of postcollectomy syndrome, which manifests itself in persistent diarrhea, which significantly reduces the social and labor rehabilitation of patients [15,26,27].
In order to reduce the risk of sutures failure after resection of the colon with the restoration of its continuity and complete or partial violation of the passage, various mechanical methods of intraoperative bowel cleansing are currently used.This approach avoids the formation of colostomy and is an alternative to two-stage treatment (for example, Hartmann's operation).In this case, the mechanical preparation of the intestine allows to remove feces and decompression of the enlarged colon before the formation of the anastomosis.At the same time, the available literature data at the moment do not allow making an unequivocal conclusion about the advantages of this method before operations performed without prior preparation of the large intestine.
In 1988, an experimental randomized study conducted by Ravo et al. [28], showed that if the intestinal contents in contact with the anastomosis are removed, the latter can be safely applied even in peritonitis.Several methods of mechanical preparation of the intestine during emergency surgery have been described.The most acceptable are intraoperative colon lavage or mechanical decompress anastomosis failure [29][30][31][32].In 2004, a systematic review of Trompetas [15] concluded that there was no evidence to state that mechanical preparation of the intestine lead to a decrease in the risk of the anastomosis failure after surgery.So, according to Ortiz et al. [31], resection of the intestine and primary anastomosis can be safely performed without mechanical preparation.
Considering the above , the described methods of surgical treatment of patients with colon cancer complicated by obturation obstruction do not allow to achieve the shortest possible time to restore the continuity of the gastrointestinal tract in cases of two-stage operations or satisfactory results after one-stage operations with a primary anastomosis.
Alternatively, in the treatment of this pathology, various minimally invasive methods of temporary decompression of the colon at the first stage were suggested, followed by radical surgery and the formation of a primary interintestinal anastomosis.
With the development of technology, tools, experience, there have been reports of video-assisted colostomy.The method of temporary decompression, based on the loop colostomy from a mini-access, that is, performing videoassisted colostomy, allowed to resolve intestinal obstruction at the first stage of treatment, and perform a radical surgical intervention in relation to intestinal tumors at the second stage.Thus, temporary decompression from a miniaccess, according to A.V. Pugayev and E.E.Achkasov, allowed to reduce the frequency of postoperative complications to 7.2% at the first stage, and the mortality rate at this stage was 1.8%.Also, the authors note 100% absence of postoperative intestinal paresis and early activation of patients.Radical operations were performed in 90.7% of patients with a total postoperative mortality of 6.5%.The authors emphasize that performing a colostomy from a mini-access allows resolving acute obturation colonic obstruction and preserving the life of 98.2% of patients, compensating for water and electrolyte disorders and adequately preparing the patient for a radical operation [33].The advantage of the method is also the additional diagnosis of both local and distant tumor process.V.A. Osipov reported successful laparoscopic colostomy in 16 patients.No deaths at the decompression stage indicate good immediate results [34].
The use of endoscopic methods allowed to decompress the colon in patients with acute obturation colonic obstruction.However, the work of recent years shows that endoscopic methods are technically acceptable and clinically effective if the intraluminal length of a tumor does not exceed 3-5 cm [35,36].
The method suggested in the 80s of the last century, based on the hyper-or hypothermic destruction of a tumor using laser, cryosurgical techniques or argon plasma coagulation, proved to be very successful [37,38].Some of the best indicators were observed when performing laser photocoagulation (the effect of manipulation averaged 90%) [37].However, one of the drawbacks of this approach is the need to perform repeated manipulations every 5-9 weeks to avoid recurrence of obstruction [38].It is also necessary to note the fact that this method of temporary decompression should be performed for patients who are not supposed to undergo radical surgery in the future, since its local spread may occur due to the destruction of the tumor tissue.Complications of these manipulations: perforation (4.1%), fistula (3.2%), abscess (1.7%), bleeding (4.1%) [37].As noted by S.Y.Dvoretsky et al ., the complete or partial recanalization of the tumor in 21 patients out of 31 (67.7%)allowed to conduct a full preoperative preparation and perform a planned surgical intervention [39,40].
In the late 80s -early 90s of the last century, domestic scientists offered methods for endoscopic recanalization with a drainage tube.In particular, it concerns the works of prof.Y.V. Sinev and prof.G.V. Pakhomova [41,42].In the early 2000s, works from abroad appeared reporting endoscopic recanalization with a drainage tube during colonic obstruction (transanal drainage tube).Technical (possibility of installing a drainage tube) and clinical (eliminating the symptoms of obstruction) success of the method was 93.9% and 86.4%, respectively.According to various authors, the frequency of perforations after endoscopic recanalization reached 4.5-8.5%,and overall mortality ranged from 1.5% to 9.8% [43][44][45][46].
In the 1990s, self-expanding metal stents [15,47] were developed for the palliative treatment of inoperable patients [15,47], which are installed endoscopically with the help of a guide through tumor contraction.A number of authors who support the concept of stents as a temporary "bridge to surgery", argue that the method allows to compensate for water-electrolyte and nutritional disorders in a patient, manage the associated diseases, clarify and finalize the diagnosis, involve specialists from related fields.The first studies of this method showed extremely encouraging results: a reduction in the incidence of complications and mortality, an increase in the percentage of completion of primary anastomoses and minimally invasive operations [48][49][50].
However, when the results of 6 existing randomized studies using stents as a "bridge to surgery" [51][52][53][54][55][56] were analyzed, it was very difficult to draw general conclusions from these studies, especially given that 3 of them were not completed [51, 55 , 56].
In 2009, Cheung et al. [52] studied the question whether it is possible to underwent laparoscopic resection of colon and primary anastomosis without making the stoma.All patients in their study were operated on by one surgical team, the result -67% of operations were performed laparoscopically with a primary anastomosis, almost a third of patients in both groups underwent Hartmann's operation.
The purpose of the Pirlet study et al. (2011) [56] was to identify the possibility of placing the stent as the first stage before a radical surgery.Elimination of the symptoms of obstruction in patients after installation of a stent reached only 40%, while the number of complications was 50%.The stoma rate was 43% in the stents group and 57% in the surgical group.Given the large number of complications in the stents group, the study was discontinued.
The study van Hooft et al. [55] was ended beforehand by the Data Safety Monitoring Committee due to the high number of complications in the stenting group as compared to conventional emergency surgery.
Alcantara et al. [51] randomized 28 patients.The study was ended beforehand due to a higher level of failure of the anastomosis in the emergency surgery group (30.7%).
In 2011, Ho et al. [54] noted that the rate of clinical success in tumor stenting was 70%.The incidence of complications in the stenting group was 35% compared to emergency surgery, where it was 58%.Fatalities in the stenting group were not observed, in the emergency surgery group the mortality rate was 16%.
In a clinical study conducted by Ghazal et al. (2013) [53], the endoscopic stenting followed by a planned colectomy (left-sided hemicolectomy or anterior resection) was compared to a total colectomy with ileorectal anastomosis under conditions of emergency surgery.In our opinion, in this study the types of operations performed in two groups are not comparable, and the results of surgical intervention are controversial.
As for the survival, the results are similar in patients undergoing stenting as a "bridge" to surgery as compared to emergency surgery [57][58][59].At the same time, early metastasis is more common in patients with stents [60].When patients with stents were compared with elective (without obstruction) colon cancer patients, differences in 5-year survival were not observed (60% vs. 58%, respectively) [60].
In the process of accumulating clinical experience and publishing a huge amount of work, certain shortcomings and constraints of the unambiguous use of self-expanding stents as a staged treatment were identified.Constraining factors are the cost of colorectal stents, and one of the main conditions for successful stenting is the conduction of the procedure at the multidisciplinary hospital with the participation of experienced endoscopists [18].
There is no doubt that more research is needed before installation of stents may be considered as a standard technique.The longer hospital stay of such patients, on the one hand, and the possibility of performing a videolaparoscopic radical operation with a primary anastomosis, on the other hand, require careful individual approach to each patient.

CONCLUSION
Thus, over the past few decades, the treatment of complicated colorectal cancer has qualitatively changed.For lesions of the right half of the colon, the standard treatment is right-sided hemicolectomy with the formation of the primary ileaocolonic anastomosis.Currently, modern minimally invasive methods that allow temporary colon decompression and subsequent surgery with a primary anastomosis, significantly reducing mortality, the incidence of complications, and improving the social and labor rehabilitation of patients, are promising for lesions of the left colon.At the same time, the lack of comparative data regarding the effectiveness of various temporary methods of decompression of the colon in acute obturation colonic obstruction determines the relevance of the development of this area.