1. Introduction

One of the main challenges in gastrointestinal surgery is pathology of the right colon primarily malignant tumors, as well as diverticulosis, Crohn’s disease, traumatic injuries, large benign tumors, and certain other conditions. All of these require resection of the right colon and restoration of intestinal continuity through a small-to-large intestinal anastomosis. The steady increase in colorectal cancer incidence over recent decades is associated with a rise in the number of surgeries, an expansion of indications for radical tumor removal, and primary anastomosis creation. Right-sided colon cancer accounts for 30–40% of cases, and tumor rupture remains the most fatal complication (5–20%) [20].

Most patients (up to 92%) with complicated right-sided colon cancer in general surgical hospitals undergo right hemicolectomy, as well as bypass anastomoses and loop colo- or ileostomies [34]. Colon resection can be total or partial. After resection, the remaining ends of the intestine are either joined or, if joining is not possible, the distal end is closed while the proximal end is exteriorized to create a stoma. Hemicolectomy is usually accompanied by lymphadenectomy the removal of the nearest lymph nodes. Partial or segmental resection involves removal of a portion of the colon, typically one-third or one-quarter. After resection, the bowel ends are sutured either “end-to-end” or “end-to-side.” Sometimes surgery is performed in two stages: initially, the diseased segment is removed, and a colostomy is created, followed 4–6 months later by restoration of bowel continuity [36].

Debates about the superiority of one method over another are inappropriate, as treatment strategy must be individualized for each clinical case [32]. In some patients, dehydration and electrolyte disturbances may develop due to ileostomy, often requiring rehospitalization for intravenous therapy. Ileocolic anastomosis is performed after primary removal of the right colon either as “end-to-side,” “end-to-end,” or “side-to-side.” In 90% of operations, primary ileocolic anastomosis is performed to preserve natural intestinal passage. However, anastomotic leakage after emergency right hemicolectomy occurs in up to 15% of cases, with mortality increasing tenfold [1,33].

Alongside the ascending colon, the ileum is an active surgical area in emergency surgery, often affected by acute obstruction due to incarcerated hernia, adhesions, gallstones, or intussusception. Acute mesenteric vessel thrombosis is another serious problem [23]. Traditionally, complicated colon tumors are treated in general surgical hospitals where surgeons often have limited experience performing hemicolectomies, resulting in worse immediate outcomes compared to specialized centers.

For bowel obstruction, a surgeon may limit intervention to a bypass or proximal stoma (including ileal), but in cases of tumor rupture with peritonitis and paracancerous abscess, tumor removal should ideally be completed in a safe manner by coloproctologists [25].

Colorectal obstruction accounts for 29–40% of acute intestinal obstruction cases, with tumors causing 70–91% of them. Non-tumoral obstruction develops only in the presence of predisposing anatomical factors; volvulus constitutes 10–18% of non-tumoral colonic obstruction [2]. Inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis, are also significant [27]. About three-quarters of Crohn’s patients require surgery despite medical therapy. Surgery does not cure Crohn’s disease but improves quality of life. Indications include failure of medical therapy and complications such as stricture-induced obstruction, massive bleeding, perforation with peritonitis, fistula formation, infection, sepsis, and toxic megacolon [27].

Cecal volvulus accounts for 20–40% of all colonic volvuli and 1–1.5% of all intestinal obstructions, typically in patients aged 40–62, with a female-to-male ratio of 4:1. Complications include bowel ischemia (23.8–44.2%), necrosis (36.7%), perforation (23%), and peritonitis (41.6–43%) [2]. In cases of uncertain bowel viability, resection is preferred.

In the US, where adhesions were long unrecognized as a separate entity, 300,000 patients are hospitalized annually with adhesions, costing $1 billion. Adhesions develop in 67–93% of patients after abdominal surgery [26]. Surgical options include laparotomy, enterolysis, resection with anastomosis, bypass jejuno- or ileotransverse anastomosis, and laparoscopic adhesiolysis [9]. About 40% of all abdominal surgeries result in adhesions, with up to 60% of laparotomies performed for adhesive obstruction [22].

Intussusception accounts for 2–10% of acute intestinal obstruction, more common in children but also in adults [4]. Thickened bowel forms occur in 2.2% of cases. Surgical management depends on severity and location [11].

Emergency surgery encompasses rapidly progressing pathologies that require immediate treatment, including acute mesenteric ischemia, which remains a significant unresolved problem in urgent surgery [12].

Global literature widely discusses self-expanding stents in malignant obstruction. Stenting avoids emergency stoma creation [37] but carries risks of migration, re-obstruction, or perforation [34]. High postoperative mortality highlights the urgency of defining optimal surgical strategies for acute obstructive colonic tumors, where approaches range from stoma creation to radical surgery with ileocolic anastomosis [18;23]. Ileostomy remains necessary in some pathologies and trauma [29].

Patients with peritonitis are more challenging to manage than those with simple obstruction. Extensive resection is often required to eliminate the source of peritonitis, while obstruction may be treated with a proximal stoma via a mini-access. Surgeons face three options: 1) ileocolic anastomosis (e.g., U-shaped with enterostomy), 2) staged surgery with obstruction resection and anastomosis within 4 days, 3) resection with stoma and delayed closure [23].

Optimal closure is via anastomosis, but leakage occurs in up to 15% in peritonitis. Overall, primary anastomoses remain the domain of specialized centers. Emergency resections for complicated tumors have worse long-term outcomes than elective surgery [18]. According to V.I. Yesin et al. (2011), primary extended resection with colostomy leads to persistent disability in 50% of patients [10].

Various anastomosis techniques exist (end-to-end, end-to-side, side-to-side; handsewn or stapled), with no consensus on suture layers [38]. Literature describes over 200 types of stomas, each with pros and cons [38]. Melnikov P.V. et al. (2020) noted that intracorporeal anastomosis (ICA) in right hemicolectomy can be safely integrated into routine practice, potentially improving immediate outcomes [15].

In acute obstructive colonic obstruction, subtotal colectomy with ileosigmoid or ileorectal anastomosis or segmental resection with primary anastomosis is preferred [13]. Segmental resection avoids post-colectomy syndrome (chronic diarrhea). Lack of consensus on timing, surgical access, anastomosis method, and tactics is due to high leakage (6–25%), infectious complications (26–40%), and mortality (3–7%), averaging 5.2% [16].

Ileocolic anastomoses are classified by: 1) formation method, 2) type, 3) number of suture layers, 4) suture characteristics, 5) depth of bowel wall capture, 6) knot placement. They are also divided into valve-bearing and non-valve-bearing [16].

Laparoscopic surgery, including ileocolic anastomosis (ICA), is becoming standard for many colonic diseases. Mechanical laparoscopic stapling defects occur in 18% of cases [35]. Due to high equipment cost, handsewn anastomosis remains prevalent. The first compression device was the “Murphy Button,” later modified by H.H. Kanshin into the AKA device [17]. Endoscopic techniques have made laparoscopic right hemicolectomy the standard for right-sided colon cancer [8]. Compared to open surgery, laparoscopy reduces postoperative complications, particularly infections. Success depends on surgeon experience [24].

Intracorporeal anastomosis is a next step in laparoscopic colon surgery [5]. Open surgery shows anastomotic leakage in 1.5–15.2% of cases, mortality 0–4.7%, wound infection 2.5–25%, and obstruction 2.5–20% [6]. Resection extent depends on tumor spread; at least 12 nearby lymph nodes should be removed. Blood supply variations must also be considered [28].

Creating an optimal ileocolic anastomosis is crucial. Difficulties arise from connecting functionally and diametrically different segments, ideally preserving ileocecal function [14].

2. Conclusions

There is a growing incidence of right colon and terminal ileum pathologies requiring segmental or right hemicolectomy with restoration of intestinal continuity. However, standardized approaches are lacking. In peritonitis, surgeons face difficult choices between high-risk anastomosis or staged surgery often involving ileostomy, highlighting the medical and social significance of the problem and the need for further research.