Anatomical and physiological barriers
Large bowel surgery is objectively more difficult than manipulation on the small intestine. This is due to four key factors that directly affect the course of the intervention:
- The organ wall is significantly thinner, which requires extremely delicate work from the surgeon during suturing.
- The blood flow is less intense, so tissues heal more poorly and slowly.
- The peritoneal coverage is absent in some areas—certain zones are located retroperitoneally, depriving them of the serous membrane necessary for rapid fusion.
- The aggressive microflora creates a colossal threat of abdominal cavity infection when the lumen is opened.
That is why the classical two-row intestinal suture is categorically unsuitable here. To ensure maximum tightness, surgeons are required to apply a three-row suture.
Classification of Procedures
All surgical procedures in this area of the gastrointestinal tract are divided into two large groups:
- Standard operations: basic manipulations, such as standard wound closure or removal of the vermiform appendix (appendectomy).
- Extensive operations: large-scale interventions indicated for malignant neoplasms, polyposis, ulcerative colitis, as well as volvulus, intussusception with necrosis, extensive trauma, and fistulas.
Extensive interventions, in turn, are divided into palliative and radical. Palliative ones aim to alleviate the patient's condition without removing the focus of the disease itself. These include the creation of an intestinal fistula (colostomy), creation of an artificial anus (anus praeternaturalis), or formation of a bypass anastomosis. Radical operations imply the complete removal of the pathological focus (for example, single-stage resection of the transverse colon or sigmoid colon).
Radical resections: hemicolectomies
During radical surgical treatment, the affected area is removed as a single block together with regional lymph nodes and the mesentery, after preliminary ligation of the main vascular trunks.
- Right hemicolectomy: the right half of the intestinal tube is excised. The removed block includes the cecum with the appendix, about 10 cm of the terminal ileum, the ascending colon, the hepatic flexure, and the right half of the transverse colon. After removal, an anastomosis is formed between the stump of the small intestine and the remaining transverse colon (end-to-side or side-to-side connection types are used).
- Left hemicolectomy: the left half of the transverse colon, the splenic flexure, and the descending and sigmoid colons are removed. The anastomosis is applied between the transverse colon and the stump of the sigmoid colon (or the initial section of the rectum). An end-to-end connection type is used here.
Anastomosis formation technique
The connection of intestinal tubes requires a strict sequence. Using the example of an end-to-end enteroenteroanastomosis, the process looks as follows:
- First, the posterior lips of the anastomosis are sutured using a continuous catgut suture.
- Then, the anterior lips are connected with a special locking suture (the so-called Schmieden's inverting suture).
- Finally, interrupted seromuscular sutures are applied to the anterior wall of the anastomosis. This stage is critically important for additional reinforcement of the structure and reliable peritonealization of the intervention zone.
All such operations are performed exclusively under endotracheal anesthesia.
Briefly: answers to topical questions
Which blood vessels must be ligated when performing a right hemicolectomy?
When performing a right hemicolectomy, it is necessary to ligate the ileocolic, right colic, and middle colic arteries.
- Ileocolic artery (a. ileocolica) — ligated at the base.
- Right colic artery (a. colica dextra) — ligated at its origin.
- Middle colic artery (a. colica media) — ligated at its origin or its right branch is ligated.
Which blood vessels are ligated during left hemicolectomy?
During left hemicolectomy, the left colic artery and the middle colic artery (or its left branch) are ligated.
- Left colic artery (a. colica sinistra) — ligated at its origin.
- Middle colic artery (a. colica media) — the main trunk is ligated at its origin or only its left branch is ligated.
How is Schmieden's continuous inverting suture technically performed (which layers are sutured)?
Schmieden's continuous inverting suture is performed by suturing through all layers of the intestinal wall.
The suture thread is always passed in one direction — from inside out. The needle sequentially pierces the wound edges: first from the mucosal side, exiting onto the serosa on one edge, and then similarly from the mucosa to the serosa on the other edge. When the thread is tightened, the wound edges are inverted (turned inward) into the lumen of the intestine, ensuring tight approximation of the sutured areas by their serous surfaces.
Which layers of the intestinal wall are included in each row of the classical three-layer suture on the colon?
The classical three-layer suture on the colon consists of one inner row and two outer rows.
- First row (inner) — a row of marginal sutures (continuous catgut suture) that is full-thickness and passes through all layers of the wall: mucosa, submucosa, muscular layer, and peritoneum.
- Second and third rows (outer) — seromuscular sutures that capture only the serosa (peritoneum) and muscular layer without penetrating the intestinal lumen.
Which specific parts of the colon are located retroperitoneally and lack a serosal coat on the posterior wall?
Some areas of the colon have a retroperitoneal location, but the parts lacking a serosal coat on the posterior wall are classified as mesoperitoneal.
These parts include:
- Ascending colon (colon ascendens) — covered by peritoneum anteriorly and laterally, while lacking a peritoneal coat posteriorly.
- Descending colon (colon descendens) — located mesoperitoneally and has an extraperitoneal area on the posterior wall.
Class and exam questions
Why is a three-layer suture used on the colon instead of a two-layer one?
This is due to anatomical features: the organ wall is thinner, blood supply is poorer, and it contains highly pathogenic microflora. A three-layer suture is necessary for maximum tightness and prevention of peritonitis.
What is the core purpose of palliative intestinal surgery?
They do not treat the underlying disease, but they save lives or significantly relieve symptoms. Such interventions include colostomy, creation of an artificial anus (anus praeternaturalis), and formation of bypass anastomoses.
Which segments are removed during right hemicolectomy?
The terminal ileum (about 10 cm), cecum with appendix, ascending colon, right colic flexure, and the right half of the transverse colon are excised en bloc.
What surgical approaches are used for colon resection?
Depending on the location of the pathology, surgeons choose midline, paramedian, transrectal, or combined abdominal wall incisions.
What else to study on this topic
- Indications for extensive resections: volvulus, intussusception with necrosis, extensive trauma, and fistulas.
- Features of mesentery mobilization and lymph node dissection in malignant tumor resection.
- Technique of applying Schmieden's inverting suture to the anterior lips of the anastomosis.
- Specifics of creating end-to-side and side-to-side anastomoses.
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