Intestinal Problems

Anatomy

• Tubular structure

• 6 meters in adults

• Three segments lying in series:

– Duodenum

• most proximal segment

• lies in the retroperitoneum immediately adjacent to the head and inferior border of the body of the pancreas.

• demarcated from the stomach by the pylorus and from the jejunum by the ligament of Treitz.

Reyes, Christopher Brian M.

Anatomy

– Jejunum and Ileum. • The jejunum and ileum lie within the peritoneal cavity and are

tethered to the retroperitoneum by a broad-based mesentery. • No distinct anatomic landmark demarcates the jejunum from the

ileum • the proximal 40% of the jejunoileal segment is arbitrarily defined

as the jejunum and the distal 60% as the ileum. • The ileum is demarcated from the cecum by the ileocecal valve.

• contains mucosal folds – plicae circulares or valvulae conniventes that are visible

upon gross inspection – visible radiographically and help to distinguish between

small intestine and colon – more prominent in the proximal intestine than in the

distal small intestine



Anatomy • served by rich vascular traversing through the

mesentery. – base of the mesentery attaches to the posterior

abdominal wall to the left of the second lumbar vertebra and passes obliquely to the right and inferiorly to the right sacroiliac joint.

• The blood supply of the small bowel comes entirely from the superior mesenteric artery – Proximal duodenum – celiac trunk

• The superior mesenteric artery courses anterior to the pancreas and the duodenum, where it divides to supply the pancreas, distal duodenum, entire small intestine, and ascending and transverse colon.


Anatomy • There is a collateral blood supply to the small

bowel by vascular arcades.

• Venous drainage of the small bowel parallels the arterial supply, with blood draining into the superior mesenteric vein, which joins the splenic vein behind the neck of the pancreas to form the portal vein.



Anatomy

Intestinal Trauma • The majority of duodenal injuries are caused by

penetrating trauma

• accompanied by other intra-abdominal injuries

• motor vehicle accident causing impact of the steering wheel on the epigastrium

– most common mechanism

• Hyperamylasemia occurs in about 50% of patients with blunt injury to the duodenum


Intestinal Trauma • Plain films of the abdomen

– mild scoliosis, obliteration of the right psoas shadow, absence of air in the duodenal bulb, or air in the retroperitoneum outlining the kidney

• Definitive diagnosis requires a upper gastrointestinal series or a CT scan of the abdomen with oral and IV contrast in hemodynamically stable patients

– Extravasation of contrast material is an absolute indication for laparotomy.


Intestinal Trauma • Intraoperative evaluation of the duodenum

requires adequate mobilization of the duodenum by means of a Kocher maneuver.

– The hepatic flexure of the colon is also mobilized to provide adequate exposure of the anterior wall of the second portion, and examination of the third and fourth portions of the duodenum should also be done.

– The presence of retroperitoneal hematomas around the duodenum should raise suspicion of an associated pancreatic injury.


Intestinal Trauma • If the distal antrum or pylorus is severely damaged

– reconstructed with a Billroth I or II procedure

• With the almost universal use of CT for the diagnosis of blunt abdominal injury, injury to the small intestine can be missed.

• 80 Wounds of the mesenteric border also can be missed if the exploration is not comprehensive.

• Most injuries are treated with a lateral single-layer running suture.

• Multiple penetrating injuries often occur close together.

• Rather than performing many lateral repairs, judicious resections with end-to-end anastomosis may save considerable time.


Small Bowel Obstruction

- blockage of the small bowel resulting to failure of intestinal contents to pass through

- most frequently encountered surgical disorder of the small intestine

Reyes, Lisha Alyanna A.

Schwartz’s Principles of Surgery, 9th Ed

• Intraluminal

– foreign bodies

– gallstones

– meconium

• Intramural

– tumors

• Extrinsic

– adhesions

– hernias



• partial small bowel obstruction vs

complete small bowel obstruction

• simple mechanical obstruction - obstruction present, no vascular compromise

• strangulated bowel obstruction - increase in intraluminal pressure that intestinal microvasculature is impaired causing intestinal ischemia and necrosis



• closed loop obstruction - both the proximal and distal segment of the intestine is obstructed

• incarceration - constricted hernia that bowel becomes irreducible



Clinical Manifestations • colicky abdominal pain

– as gas and fluid accumulate within intestinal lumen proximal to obstruction, increase effort to overcome obstruction

– earlier stage: hyperactive bowel sounds – later stage: minimal bowel sounds

• vomiting – proximal obstruction > distal obstruction – characteristic: feculent (chronic distal obstruction)

• abdominal distention – distal obstruction > proximal obstruction

• partial obstruction: continuous passage of flatus and/or stool • strangulated obstruction: abdominal pain is disproportionate

to abdominal findings highly suggestive of ischemia – tachycadia, localized abdominal tenderness, fever, marked

leukocytosis, acidosis, need for early surgical intervention



Goals of Diagnosis

• distinguish mechanical obstruction from ileus

– ileus: no mechanical barrier, characterized by impaired intestinal motility that prevents intestinal contents to pass

• determine etiology of obstruction

• discriminate partial from complete obstruction

• distinguish simple from strangulating obstruction



• Abdominal Series

– Sn 70-80%, low Sp ileus and colonic obstruction mimic

– triad: dilated of dilated small bowel loops (>3 cm in diameter), air-fluid levels seen on upright films, paucity of air in the colon

– false negative: obstruction in the proximal bowel, bowel filled with fluid but no air (closed loop obstruction)



• CT (Sn 80-90%, Sp 70-90%)

– prognostic and therapeutic: appearance of contrast after 24 hours is predictive of nonsurgical resolution of bowel obstruction

– discrete transition zone with dilation of bowel proximally

– decompression of bowel distally

– colon containing little gas or fluid



• CT (Sn 80-90%, Sp 70-90%) – closed loop: U shaped dilated bowel loop with a radial

distribution of mesenteric vessels converging toward a torsion point

– strangulation: thickening of bowel wall, pneumatosis inestinalis (air in bowel wall), portal venous gas, mesenteric haziness, poor uptake of IV into wall of affected bowel

– low sensitivity (>50%): low grade or small partial obstruction



• Small Bowel Series (small bowel follow-through)

– water soluble contrast agents Gastrografin if perforation is suspected; oral or NGT

– abdominal radiograph taken serially

– greater sensitivity in detection of luminal and mural etiologies, primary intestinal tumor

• Enteroclysis

– 200-250 mL barium followed by 1-2 L methycellulose in water; proximal jejunum via nasoenteric catheter

– double contrast: mucosal surface assessment, detection of small lesions



Treatment

• fluid resuscitation

• NG decompression

> Conservative Treatment

– partial small bowel obstruction

– obstruction occurring in the early postoperative period

– intestinal obstruction due to Crohn’s disease

– carcinomatosis

* non operative therapy: bowel rest, continuous hydration/TPN

*observe for signs and symptoms of strangulation, intestinal ischemia, and peritonitis: surgical procedure





Treatment

• surgical procedure is dependent on etiology

• adhesions: lysed

• tumors: resected

• hernias: reduced and repaired

• observe fore viability: color, peristalsis, marginal arterial pulsations

• nonviable bowel: resected



Prevention of Adhesion

• good surgical technique

• careful handling of tissue

• minimal exposure of peritoneum to foreign bodies



Ileus and Intestinal Pseudo-obstruction

• clinical syndrome caused by impaired intestinal motility

• characterized by signs and symptoms of intestinal obstructions in the absence of lesion-causing mechanical obstruction



• Ileus

- temporary motility disorder reversed with time as inciting factor is corrected

- most frequently implicated cause of delayed discharge following abdominal operation

- surgical stress-induced sympathetic reflexes

- inflammatory response mediator release

- anesthetic/analgesic effects

• Intestinal

Pseudo-obstruction

- comprises a spectrum of specific disorders associated with irreversible intestinal motility







Clinical Manifestations

• inability to tolerate liquids and solids

• no flatus or bowel movement

• vomiting

• abdominal distention

• diminished or absent bowel sounds



Diagnosis: Ileus

– persists beyond 3-5 days postoperatively • Post-operative motility

o small intestinal: 24 hours

o colonic: 48 hours

o gastric: 3-5 days

o listening for bowel sounds not reliable

o functional evidence: passing of flatus or bowel movement

– review medications

– measurement of electrolytes

– radiograph: difficulty in distinguishing mechanical obstruction from ileus

– CT scan: test of choice

• detect presence of intra-abdominal abscess

• evidence of peritoneal sepsis

• rule out mechanical obstruction



Diagnosis: Chronic Pseudo-obstruction

– manometric studies: disorder of intestinal motility

– laparotomy or laparoscopy with biopsy: establish specific underlying cause



Treatment: Ileus

• limiting oral intake

• correcting underlying cause

• NG decompression

• fluid and electrolyte or TPN administration

• postoperative ileus – early ambulation

– administration of NSAIDs with reduction of opioid dosing

– perioperative thoracic epidural anesthesia/analgesia with local anesthetics with reduction or systemic opioids reduced duration of postoperative ileus

– alvimopan: peripherally active μ-opioid receptor antagonist, reduce duration of postoperative ileus, hospital stay, rate of readmission in several prospective, randomized placebo-controlled trials with subsequent meta-analysis



Prevention: Ileus



Treatment: Chronic Pseudo-obstruction

• palliative: fluid, electrolyte, and nutritional management

• no standard therapy is curative

• refractory disease: limit oral intake, long term TPN

• decompressive gastrostomy

• extended small bowel resection



Inflammatory Diseases of the Small Intestine

Reyes, Ma. Katrina Bernadette O.

Crohn’s Disease Etiology/Pathogenesis: Unknown

Clinical Manifestations:


Reyes, Ma. Katrina Bernadette O. Diagnosis:

Treatment:

a. Medical – Anti-inflammatory drugs, anti-biotics, corticosteroids

b. Surgery – Bowel resection

TB Enteritis Etiology: Mycobacterium tuberculosis

Clinical Manifestations: Abdominal pain

Hematochezia

Palpable mass

Fever

Weight loss

Night sweats


Diagnosis:

CT scan of the abdomen

Ascitic fluid analysis

Peritoneal biopsy

Colonoscopy

Treatment: Resection with Quadruple Anti-TB therapy


Typhoid Enteritis Etiology/Pathogenesis: Salmonella typhi

Clinical Manifestations: Bleeding

Abdominal pain

Diarrhea

Fever


Diagnosis: C/S of stool

Biopsy

Treatment: a. Medical – Broad spectrum antibiotics

b. Surgical – Bowel resection

(bleeding and perforation)


Meckel’s Diverticulum

Reyes, Maria Laura Bielle G.


• Most prevalent congenital anomaly of the GI tract

• Designated as true diverticula

• Location varies but usually found in the ileum within 100cm of ileocecal valve



• occurs on the antimesenteric border of the ileum, usually 40-60 cm proximal to the ileocecal valve

• 3 cm long and 2 cm wide

• Slightly more than one half contain ectopic mucosa

• Meckel diverticulum is typically lined by ileal mucosa, but other tissue types are also found with varying frequency.



• Mnemonics for describing Meckel’s Diverticula (the “rule of twos”):

– 2% prevalence

– 2:1 female predominance

– Location of 2 ft proximal to the ileocecal valve in adult

– ½ of those who are symptomatic under 2 yrs of age


Pathophysiology

• Failure or incomplete vitelline duct obliteration results in a spectrum of abnormalities, most common is Meckel’s diverticum

• Remnant of left vitelline artery can persist to form mesodiverticular band tethering a meckel’s diverticulum to the ileal mesentery



• Asymptomatic unless associated complications arise

• Symptomatic Meckel’s diverticula presents:

– Bleeding: most common presentation in children

– Intestinal obstruction: most common in adults

– diverticulitis



• Bleeding is usually result of ileal mucosal ulceration

• Intestinal obstruction can result from several mechanisms: – Volvulus of intestine around

fibrous band attaching the diverticulum to umbilicus

– Entrapment of intestine by a mesodiverticular band

– Intussusception with diverticulum acting as lead point

– Stricture secondary to chronic diverticulitis


Diagnosis

• Routine laboratory findings, including CBC count, electrolyte levels, glucose test results, BUN levels, creatinine levels, and coagulation screen results

• Aymptomatic

– radiographic imaging

– Endoscopy

– At the time of surgery

• Symptomatic

– Radionuclide scans (99mTc-pertechnetate) can be helpful in the diagnosis of Meckel's diverticulum; however, positive only when the diverticulum contains associated ectopic gastric mucosa that is capable of uptake of the tracer

– Enteroclysis - associated with an accuracy of 75%, but usually is not applicable during acute presentations of complications related to Meckel's diverticula

– Angiography - can localize the site of bleeding during acute hemorrhage related to Meckel's diverticula


Diagnosis

• Technetium-99m pertechnetate scintiscan (0.2mCi/kg in children and 10-20mCi in adults) – The pertechnetate is taken up by gastric mucosa and

after intravenous injection of the isotope, the gamma camera is used to scan the abdomen. Gastric mucosa secretes the radioactive isotope; thus, if the diverticulum contains this ectopic tissue, it is recognized as a hot spot. • The Meckel scan is the preferred procedure because it is

noninvasive, involves less radiation exposure, and is more accurate than an upper GI and small-bowel follow-through study.


Treatment

• Symptomatic Meckel’s Diverticula

– Diverticulectomy with removal of associated bands connecting the diverticulum to abdominal wall or mesentery

– Segmental ileal resection


Treatment

• Asymptomatic Meckel’s Diverticula

– Prophylactic removal of asymptomatic Meckel’s Divertivula

– Prophylactic diverticulectomy


Small bowel Neoplasms

Reyes, Nicole Marie O.

Incidence

• Adenocarcinomas – 35-50%

• Carcinoid tumors – 20-40%

• Lymphomas – 10-15%

• Adenomas are the most common benign neoplasms of the small intestine

• 50- 60 years of age • Consumption of red meat, smoked or cured foods,

crohn’s disease, celiac sprue, FAP

Schwartz’s principle on surgery 9th Ed


Clinical manifestation

• Mostly asymptomatic

• Physical Exam- unrevealing

– Palpable abdominal mass- 25%

• Partial small bowel obstruction, abdominal pain and distention, nausea and vomiting

• Hemorrhage

• Adenocarcinoma-> duodenum

– Diagnosed earlier



• Carcinoid tumors

– Diarrhea, flushing, hypotension and tachycardia

• Lymphoma

– Located in the ileum

– Partial small bowel obstruction

• GIST

– hemorrhage



Diagnosis

• Enteroclysis – 90% sensitivity – Test of choice

• CT scanning – Low sensitivity for detecting mucosal or intramural

lesion – Useful in staging

• EGD – Tumors in the duodenum – Visualize and biopsy

• Intraoperative enteroscopy

Schwartz’s principles on surgery 9th Ed


Therapy

• Duodenal tumors <1 cm

– endoscopic polypectomy

• Duodenal tumors >2 cm

– Transduodenal Polypectomy and segmental duodenal resection

– 2nd portion of duodenum- pancreaticoduodenectomy

• Jejunal and ileal malignancies

– Wide local resection

– Excision of the corresponding mesentery



• Carcinoid tumors – Segmental intestinal resection and regional

lymphadenectomy

• small Intestinal lymphoma – Localized: Segmental intestinal resection adjacent

mesentery

– Diffusely affected: chemotherapy

• GIST – Segmental resection

– Resistant to chemotherapy



Outcomes

• Complete resection of duodenal adenocarcinoma – Post operative 5 year survival rate= 50-60%

• Complete resection of adenocarcinoma in jejunum or ileum – 5 year survival rate of 5-30%

• Resection of localized carcinoid tumors – 75-95% 5 year survival rate

• Diagnosed with Intestinal lympoma – 20-40%

• GIST following resection – 35-60% 5 year survival



Intestinal Problems

Documents

duodenum reyes

christopher brian

distal duodenum

distal small intestine

anatomy jejunum

small bowel

anatomy intestinal trauma

proximal intestine