Continuing Education Activity

An intestinal stoma is one of the most common surgical procedures, in which exteriorization of either small bowel or large bowel through the anterior abdominal wall is performed. It may be performed for the management of wide ranges of benign and malignant gastrointestinal conditions on an emergency or regular basis. This activity reviews the indications for intestinal stoma and highlights the role of the interprofessional team in managing patients who undergo stoma formation.

Objectives:

• Identify the indications for an intestinal stoma.
• Describe the technique of an intestinal stoma.
• Review the complications of developing an intestinal stoma.

Introduction

The word stoma or ostomy is derived from the Latin word ostium, which means opening or mouth. An intestinal stoma is one of the most common surgical procedures. The exteriorization of either the small bowel (ileostomy) or large bowel (colostomy) through the anterior abdominal wall is performed. The first recorded intestinal stoma was created by the German surgeon Baum in 1879 to divert an obstructing colon carcinoma.[1] 

At present, the intestinal stoma is considered one of the most usual life-saving emergency procedures done worldwide.[2] It may be performed to manage wide ranges of benign and malignant gastrointestinal conditions on an emergency or elective basis. In the United States, more than 130.000 intestinal stomas are created per year to address diseases such as colorectal cancer, inflammatory bowel diseases, radiation injury, colonic diverticulitis, and fecal incontinence.[3][4] Intestinal stomas can be temporary or permanent.[5] Although intestinal stomas are considered to be life-saving surgical procedures, they are associated with various complications.

Anatomy and Physiology

The small intestine (bowel) extends from the pyloric sphincter of the stomach to the ileocecal valve, and it consists of three segments: the duodenum, the jejunum, and the ileum. The estimated length of the small intestine is thought to measure 4 to 6 meters in the living, depending on whether surgical, radiologic, or autopsy measurements are made. Embryologically, the small bowel derives from the primitive gut. The duodenum comes from the foregut, whereas the jejunum and ileum arise from the midgut. The duodenum is the most proximal section of the small bowel. It is supplied by the superior and inferior pancreaticoduodenal arteries, while veins follow the arteries and drain into the portal vein.  The duodenum combines the secretions from the pancreas and liver. The next part of the small intestine is the jejunum, where most digestion and absorption occur. The final part of the small bowel is the ileum. The superior mesenteric artery supplies the jejunum and ileum. In contrast, venous blood is drained through the superior mesenteric vein (SMV), which joins the splenic vein behind the pancreas' head to form the portal vein.[6][7][8][9]

The large intestine (bowel) extends from the ileocecal valve to the anus. It is divided anatomically and functionally into the colon (ascending, transverse, descending, and sigmoid), rectum, and anal canal. The arterial supply of the large intestine is closely linked to its embryological origin. The midgut (cecum to the distal transverse colon) is supplied by the superior mesenteric artery (SMA) through the ileocolic, right colic, and middle colic arteries. The hindgut (distal transverse colon to the rectum) is supplied by the inferior mesenteric artery (IMA). The rectum has a more complex vascularisation, with its superior third being supplied by the superior rectal artery, which stems from the IMA. In contrast, its middle and inferior third is supplied by arteries from the internal iliac arteries. Finally, the Drumond marginal artery and the Riolan’s arch constitute two major arterial anastomoses between the IMA and the SMA, which can provide valuable collateral flow in case of stenosis, occlusion, or during oncological resections of the sigmoid colon. The venous drainage follows the arterial supply except for the inferior mesenteric vein (IMV), which joins the splenic vein. The major role of the colon is water absorption and electrolyte exchange. Up to 5000 mL of fluid and up to 400 mEq of sodium can be absorbed daily in the colon under normal circumstances. Besides, the colon plays an essential role in providing essential vitamins, such as vitamins K and B12, produced by colonic bacteria.[10][11][12][13]

The ileostomy is created from a section of the ileum. Its output is directly related to the location of the stoma. If the stoma is located more proximal, there is less surface area for electrolyte and water absorption. The consistency of the output is usually soft. However, that can be affected by many conditions such as food and fluid intake, diseases like active Crohn's disease, medications, and radiation therapy. The ileostomy output is approximately 600mL per day (ranges from 500 to 700mL). This output is reduced by half in the fasting state. Ileostomy output more than 1.5L is considered excessive, and patients may be prone to dehydration.

A colostomy is an exteriorization of the ascending, transverse, descending, or sigmoid colon. There are many types of colostomy, such as double-barrel colostomy, loop colostomy, and end-colostomy. A sigmoid colostomy and the transverse colostomy are the most usual colostomy type, whereas ascending and descending colostomies are uncommon and hardly performed. The perineal colostomy is a safe and efficient perineal reconstruction technique after abdominoperineal resection for low rectal cancer. Studies show improved quality of life for these patients, as there is a preservation of the body image by invisible perineal placement. Moreover, there is reasonable continence with acceptable functional results through this technique. The content of a left-sided colostomy is normally semi-solid. The contents of transverse loop colostomies are slightly more liquid but well-formed, and the patient empties them only once a day. The more proximal the colostomy is, the more liquid the contents are.[14][15][1]

Indications

Intestinal stomas play an important role in the management of many gastrointestinal diseases. Hartman's end colostomy, loop colostomy, and ileostomy are the most usual stomas performed in surgical practice. Indications for these procedures in older persons differ from those in children. At present, colorectal cancer is the most common indication for stoma creation in adults. Unlike adults, intestinal stoma in children can manage congenital malformations of the intestine, such as Hirschsprung's disease and anorectal malformation.[16] In adults, some of the conditions requiring intestinal stoma as part of their management are colorectal cancers, inflammatory bowel disease, a diverticular disease with obstruction, penetrating bowel injuries, anal incontinence, protection of a distal anastomosis, gangrenous sigmoid volvulus, Fournier gangrene, and anastomotic leak.

End Colostomy Indications 

• Rectal resection with no restoration of continuity in below peritoneal reflection malignancy
• Perforating diverticulitis with fecal peritonitis
• Abdominoperineal rectal resection

Loop Colostomy Indications 

• Unresectable rectal carcinoma
• Protective stoma in deep anterior rectal resection
• Radiation proctitis
• Incontinence
• Complicated rectal carcinoma with stenosis
• Complex perianal fistulas in the setting of inflammatory processes

End or Loop-end Ileostomy Indications 

• Failure of an ileal pouch-anal anastomosis
• Emergency colectomy or proctocolectomy
• Massive intestinal resection in bowel ischemia
• Total proctocolectomy for familial adenomatous polyposis (FAP)
• Hereditary nonpolyposis colon cancer (Lynch syndrome) with low rectal cancer
• Total colectomy for refractory ulcerative colitis with medical management
• Total proctocolectomy for Crohn disease

 Loop Ileostomy Indications 

• Protective stoma after proctocolectomy in FAP and chronic inflammatory bowel disease (CIBD)
• Fecal incontinence
• Fournier gangrene
• Fulminant toxic colitis
• Low rectal or coloanal anastomosis
• Perineal necrotizing fasciitis
• Severe Crohn perianal sepsis
• Rectal trauma or sphincter injury
• Complex rectovaginal or rectourethral fistula
• Treatment of anastomotic leak[17][18][1][2][14]

Contraindications

There are not any absolute contraindications to stoma formation. However, carcinomatosis, as well as the short mesentery, are some relative contraindications to stoma creation. Inadequate length of mesentery disables the free-tension exteriorization of the intestine through the abdominal wall. Tension on the stoma, which is more common in obese patients, is an independent risk factor for developing a stoma complication.

Equipment

In the operating stage, surgical instrument sets depend on the type and technique of the intestinal stoma. Medical devices such as surgical staplers and staples may be used in place of sutures by many surgeons. There are various sizes and heights of staples in surgical staplers so that the most appropriate can be chosen by the surgeon. The choice of a stapler and staple height depends on the properties of the different types of tissues in the body. Tissue thickness is an important consideration in colorectal surgery. The normal thickness of the colon wall may be up to 3mm thick, whereas the normal thickness of the small bowel wall measures between 1 and 2mm. Laparoscopic tower and laparoscopic instruments such as trocars, bowel grasper, and a laparoscope are required if stoma formation is performed laparoscopically.[19]

In the maintenance stage, well-fitting bags are required as well as paste and rings, spray, adhesive remover wipes, dry wipes, powder, skin protector wipes, and belts.

Personnel

The procedure of intestinal stomas formation is usually undertaken by general surgeons. Colon and rectal surgeons have extensive stoma formation experience and might consider precious procedures. Intestinal stoma in children is performed by pediatric surgeons. However, when the stoma becomes functional, its management is done by nursing staff or entero-stomal therapists.

Preparation

Preoperative patient preparation is of major importance as it contributes to minimizing postoperative complications. Enhanced recovery after surgery (ERAS) protocols call for optimizing the patients’ functioning status before undergoing surgery as a proven means of decreasing post-surgical morbidity. Alcohol, smoking, and recreational drug consumption should be reduced to a minimum or preferably ceased. The metabolic state of the patient should also be assessed and optimized.[20]

Patient education and psychological support play an important role in improving long-term surgical outcomes as it has been proven to reduce poorly defined psychosocial complications -anxiety, depression, and agoraphobia are some of the most common- as well as promote the ostomate’s quality of life and independence.[3][21][22] Choosing and marking an appropriate site for the creation of the ostomy by a trained professional (nurse or doctor) is also critical as it prevents the complications related to the ill-fitting stoma. The apex of the infra umbilical fat fold is often considered an ideal site as it allows easy access and visualization of the stoma.[23]

The necessity of preoperative bowel preparation in elective bowel surgery settings is unquestionable. Common surgical practice includes administering mechanical bowel preparation (MBP) in conjunction with oral antibiotics, aiming to reduce the microbial load of the intestine and consequently minimalize surgical site infections (SSI). The most commonly used cathartics for mechanical bowel preparation are sodium phosphate and polyethylene glycol. In contrast, oral aminoglycosides with an anaerobic coverage profile(metronidazole or erythromycin) are the most frequently combined oral antibiotics. Although there has been much controversy over the use of the MBP routinely in patients undergoing colorectal surgery, recent guidelines by the society for healthcare epidemiology of America (SHEA) and the infectious diseases society of America (IDSA) recommend the use of a combination of parenteral antimicrobial agents and oral antibiotics to reduce the risk of SSI following colorectal operations. Besides, it is emphasized that MBP without oral antibiotics does not decrease the risk of SSI.[24][25]

Preoperative preparation might include pre-operative shaving of the abdominal wall, Folley catheter insertion, nasogastric tube placement, and adequate fluid and electrolyte resuscitation.

Technique or Treatment

Stomas can be divided into two broad categories depending on the part of the exteriorized bowel: ileostomies, involving a part of the ileum, and colostomies, created using a part of the colon. Both of these can either be end-ostomies -where the bowel is divided with the proximal part being used to form the stoma while the peripheral remains inside the abdomen as a stump with its end sutured- or loop ostomies, where the antimesenteric wall of the intestine is partially divided. The intestine is brought up to the skin, creating an ostomy with two openings, one “functional” and one unfunctional.[14] 

The main steps in creating an end-ostomy are common in both ileostomies and colostomies. First, a circular part of skin with a diameter of 2.5 to 3cm is removed at the desirable site using monopolar electrocautery, after being lifted using a Kocher clamp. The anterior rectus sheath is exposed next, after the blunt division of the overlaying subcutaneous fat. A cruciform incision is performed in the fascia, with 3 cm long limbs. The underlying muscle fibers are bluntly divided with a pair of straight scissors or a Kelly clamp to safeguard the inferior epigastric vessels. The posterior wall of the rectus sheath is thus revealed, and a vertical incision is made, dividing it and the parietal peritoneum. The proximal part of the divided bowel is then grasped with a Babcock grasper- which passes through the aperture made in the abdominal wall- and the bowel is exteriorized. The length of the bowel that ought to be protruding from the skin surface is 2 cm for colostomies and 5 cm for ileostomies. The midline incision should then be closed. Stoma maturation follows, with the excision of the protruding bowel's staple line using a No10 scalpel. The exteriorized bowel is fixed to the skin using interrupted, absorbable sutures. Ileostomies should be everted, creating a 2 to 3 cm spout protruding from the skin. Eversion is achieved by proper suturing technique: four sutures are initially passed through the subcuticular layer. A seromuscular bite is taken 4-5 cm away from the open end of the ileum, and a third full thickness is passed at the bowel's end. Colostomies can be matured either everted or flush. In the second stage, the enterocutaneous anastomosis is performed using full-thickness bites of the colon wall and dermal bites on the skin surrounding the stoma.[1][26][27]

A loop ileostomy or colostomy is performed when fecal diversion is necessary. The procedure is similar for both operations. A bowel loop with enough mobility to be moved to the surface of the skin should be identified. Ideally, when creating an ileostomy, the chosen bowel loop should be at least 12 to 20 cm away from the ileocecal valve to ensure an easy reversal of the procedure in the future. The next step is to create a small gap in the mesentery or the mesocolon, through which a Penrose tube is passed to ensure control of the bowel loop. Sutures should be used to differentiate the distal and proximal limbs of the intestine. Next, an opening in the abdominal wall is created using the same method as mentioned above-and the bowel is delivered through this. The midline incision is closed and covered with sterile drapes. An incision is made in the antimesenteric part of the bowel, which should encompass about 80% of its circumference. At this point, it is possible to exchange the Penrose tube with a plastic bridging device. The enterocutaneous anastomosis is then performed, as mentioned above.[26][28][29]

Special care should be taken to ensure the viability of the stoma. The bowel loop to be exteriorized ought to be adequately mobilized to minimize the tension exerted on the stoma. The trephine created in the abdominal wall ought to be wide enough not to strangulate the bowel loop but not so wide that the stoma will be prone to prolapse or retraction. Twisting of the protruding bowel or kinking of its mesentery jeopardizes the stoma's perfusion and is to be avoided.[30][31]

Ostomy creation can also be performed laparoscopically, displaying the well-known advantages of laparoscopic procedures such as pain minimization, post-operative ileus reduction, rapid recuperation, shorter hospitalization duration, markedly decreased adhesion formation and subsequent small bowel obstruction episodes.[32]

Complications

Although stoma formation is a life-saving surgery in managing many gastrointestinal diseases, many patients suffer complications related to the intestinal stoma. Stoma complications can be classified as early or late. Early complications, such as cutaneous irritation or hematoma, are generally treated conservatively. However, late complications such as stoma prolapse and the parastomal hernia can be managed conservatively or surgically. 10% to 70% of patients may develop stoma complications, and their quality of life and their sense of well-being can significantly be affected. The most commonly occurring complications of intestinal stoma include the following:[33][34][35][14][17]

• Ostomy prolapse
• Ostomy stenosis
• Parastomal hernia
• Cutaneous irritation
• Ostomy retraction
• Obstruction/Ileus
• Ostomy ischemia/necrosis
• Fluid and electrolyte imbalance 
• Hemorrhage/Hematoma 
• Fistula

Clinical Significance

The formation of an intestinal stoma (ileostomy or colostomy) is one of the most usual surgical operations performed by general surgeons and, in many cases, is considered to be a life-saving surgical procedure. However, up to 10% to 70% of ostomates will suffer a complication related to their ostomy, which can change the patient's life dramatically. Preoperative and postoperative stoma education is critical because patients can better manage their stoma and adapt to living life with an ostomy.

Enhancing Healthcare Team Outcomes

Patients undergoing stoma formation require an inter-professional team approach. General surgeons and other specialized surgeons such as colon and rectal surgeons and pediatric surgeons are responsible for performing the operation. However, in the postoperative period management of intestinal stoma is done by nursing staff or entero-stomal therapists. Preoperative stoma education, which is provided by nurse specialists, enables shorter hospital stays for ostomates after the surgery.[36] In addition, a psychologist may be required for patients who experience any psychosocial complications. The whole-team approach is vital in stoma formation and its management. The renewed interest in stoma formation provides for the best patient care and enhances the team’s performance.