Small Bowel Diseases PDF

SMALL BOWEL DISEASES Doctor Faculty Member Ergün Eskioğlu Istanbul Aydin University Faculty of Medicine Department of General Surgery THIN GIPS -It is the part of the digestive tract lying between the stomach and large intestine. - They consist of three...

SMALL BOWEL DISEASES Doctor Faculty Member Ergün Eskioğlu Istanbul Aydin University Faculty of Medicine Department of General Surgery THIN GIPS -It is the part of the digestive tract lying between the stomach and large intestine. - They consist of three parts. Duodenum, Jejunum, İleum Average lengths: Duodenum 20-25 cm Jejenum 100 – 110 cm İleum 150 – 160 cm - If the mesosoma (mesentery) of the small intestine is removed from the edge of the small intestine and the small intestine is extended to the table, its length is 5-6 meters (actual length)  DUODENUM THE AVERAGE IS 25 CM NO MESENTER Y. RETROPERİTONEALDİR.  DUODENUM 1- Süperior duodenum (Bulbus) : cm dir. It starts from the pylorus and ends at the neck of the gallbladder. Its anterior surface is covered with peritoneum. 2- Descending duodenum : 8-10 cm. It extends from the neck of the gallbladder along the right edge of the vertebral column to the lower edge of the 3rd lumbar vertebra. 3- İnferior transvers duodenum (Pars horizantalis): 10 cm. 3. It starts from the lower edge of the lumbar vertebrae and ends in front of the abdominal aorta. 4- Ascending duodenum : 2-5 cm. It forms the duodenojejunal junction. This part is fixed to the diaphragm by a fibromuscular band called duodenojejunal flexure suspensory ligament (Trietz ligament). WALL FLOOR S: Serosa Muscular layer Submucosa Mucosa -The mucosa contains circular plicae (Kerckring plicae), villi, lymph follicles and glands. -Except for the proximal duodenum, the small intestine receives blood supply from the SMA. -Especially ileum is very rich in lymphatic network. NERVOUS TRANSMISSION Parasympathetic innervation of the small intestine nerve comes from vagus. Sympathetic innervation is mediated by SPLANIC NERVES. It contains two important nerve plexuses : 1-Myanteric plexus (Auerbach plexus): It is located between the longitudinal muscle layer and the circular muscle layer below it. It provides the transmission of GIS contents through the lumen (peristalsis). 2-Meissner's Plexus: It is located in the submucosa between the circular muscles and the muscularis mucosa. This plexus is responsible for secretion control. SMALL INTESTINAL DIVERTIQUES :  SMALL INTESTINAL DIVERTIQUES : They can be congenital or acquired. Congenital diverticula are true diverticula. Acquired diverticula of the small intestine are most commonly seen in the duodenum (2nd in the digestive system after the colon) Meckel's diverticulum is the most common true-congenital diverticulum of the small intestine MECKEL'S DIVERTICULUM  It is the most common congenital anomaly of the digestive tract (2%).  It develops as a result of non-closure of the omphalomezenteric duct which connects the middle intestine with the yolk sac in the intrauterine period.  As a result of this channel not closing  ompholomesenteric cyst, residual fibrous band containing enterocytoma, umbilical sinus or polyp, omphalomezenteric fistula may also occur. Meckel's diverticulum is the most common. MECKEL'S DIVERTICULUM MAY BE ASSOCIATED WITH OTHER CONGENITAL MALFORMATIONS. ÖZOPHAGUS ATREZİSİ, ANORECTAL ATRESIA, SSS VE KVS MALFORMATIONS RULE OF TWOS : -Found in 2 per cent of the population -Average distance of 2 feet (60 cm) from the ileocecal valve -2 inches (5 cm) long -2 times more common in men -Contains 2 types of ectopic tissue (stomach, pancreas) COMPLİCATİONS OF MECKEL'S DİVERTİCULUM BLOODING, INTESTINAL OBSTRUCTION INFLAMMATION (DIVERTICULITIS), PER FORATION , FIBRE HERNIA AND IS THE DEVELOPMENT OF A NEOPLASM.  COMPLICATIONS: The most common symptom in children is rectal bleeding Intestinal obstruction, haemorrhage and inflammation in adults. Most symptoms occur in children under 2 years of age.  BLOODING In children under 2 years of age, Meckel's diverticulum is the most common cause of severe lower GI bleeding. The cause of bleeding is ectopic mucosa in the diverticulum. 80-85 per cent gastric mucosa. The mucosa of the pancreas, duodenum and colon may also be involved.  OBSTRUCTION It is the most common complication of Meckel's diverticulum in adult patients. Causes: 1- Vitelloumbilical band or volvulus around the sinus 2- Intussusception 3- Incarceration of the hernia sac (Littre hernia) 4- Structure formation 5- Ectopic tissue in the diverticulum 6- Internal herniation in the mesodiverticular band 7- Adhesions due to previous inflammation  INFLAMMATION : The clinical picture is very similar to acute appendicitis. Localised abscess or generalised peritonitis may develop. Meckel's diverticulum should be searched if the appendix is found normal in patients operated with the diagnosis of acute appendicitis. If diverticulitis is detected, appendectomy is also appropriate. Diverticulectomy is not necessary if Meckel's diverticulum is found incidental in a patient operated with a diagnosis of acute appendicitis and diverticulitis is not present. PER FORATION : DEEPENING OF PEPTIC ULCER, PROGRESSION OF INFLAMMATION OR EROSION BY A FOREIGN BODY MAY PER FORATE THE DIVERTIUM.  NEOPLASM : It is rare, but small bowel tumours are more likely to occur in Meckel's diverticulum. Carcinoid tumours, leimoyosarcoma and adenocarcinoma are most common. Benign tumours include leiomyoma, fibroma, haemangioendothelioma, neurinoma and lipoma.  BLIND LOOP SYNDROME The basic mechanism is excessive colonisation of bacteria in the intestine due to slow passage. It may cause diarrhoea, steatorrhoea, anaemia, weight loss, abdominal pain and neurological findings, Vitamin B12 deficiency is evident. After the diagnosis is made, the condition that slows the passage is surgically corrected. RADIATION ENTERITIS Mucosa and submucosal vessels are acutely affected. Symptoms (diarrhoea, pain, malabsorption) are transient in this period. In the late period, vascular sclerosis and involvement lead to stricture and obstruction. Radiotherapy may also cause fistula formation with enteritis and these fistulas tend not to close spontaneously. Surgery is performed if necessary. SMALL BOWEL NEOPLASMS  SMALL BOWEL NEOPLASMS Small bowel tumours are extremely rare. 3-6% of all GI tumours, Only 1% of malignant tumours of the small intestine is localised. SYMPTOMS : Macroscopic occult haemorrhage or anaemia Pain Nausea Vomiting Weight loss Constipation SMALL INTESTINE TUMOUR S BENİGN MALİGN Leiomyoma Adenocarcinoma Fibroleiomyoma Carcinoid Tumour Adenoma Leiomyosarcoma Lipoma Lymphoma  Among benign lesions, polyps are more common in the small intestine. Malignant tumours are most commonly located in the ileum. USG and CT do not provide enough informative information. Enteroclysis is the most effective method (90%). BENIGN TUMOUR S While the small ones do not give symptoms, THE BIG ONES Obstruction (partial or intermittent)Haemorrhage and Intussusception or It can lead to volvulus. BENIGN STROMAL CELL TUMOUR S LEIOMYOMA, NEUROFIBROMA LIKE SCHWANNOMA They are tumours originating from stromal cells. LEIOMYOMA is the most common and causes the most symptoms. They are usually located in jejunum and multiple. They are removed if symptomatic. BENIGN EPITHELIAL TUMOUR S ADENOMA: TRUE ADENOM, VILLOUS ADENOMA AND It may appear as BRUNNER'S Gland ADENOMES.  Brunner's gland adenomas, are the result of proliferation of the glands with ducts and stromal elements. It is most commonly seen at the junction of the 1st and 2nd parts of the duodenum. Malignant transformation is not seen. True adenomas are seen in the ileum 50% of the time. Since they are premalignant lesions, they must be removed. HAMARTOMATOUS POLYPS They usually present as a component of Peutz-Jeghers syndrome. Although it is generally accepted that they are not premalignant, carcinomatous changes have been reported rarely. OTHER BENIGN TUMOUR S Lipomas are more common in the ileum. Lipomas do not require excision unless they are symptomatic. GIS involvement is also seen in 25% of patients with neurofibromatosis. The most common sites are jejunum and stomach. Malignant transformation can be detected in 15% of the lesions. HEMANGIOM: They may occur sporadically or as a component of Osler-Weber-Rendau syndrome. They are most commonly localised in the jejunum. Angiography is the most reliable method in diagnosis.  MALIGNANT TUMOUR S OF THE SMALL INTESTINE PAİN ,  TUMOUR S OF THE PERIAMPULLAR Y REGION OBSTRUCTION , MAY CAUSE INTERMITTENT JAUNDICE OR OCCULT BLOOD PALPABL MASS, IN THE GESTA. BLEEDING AND  TREATMENT INVOLVES WIDE DIARRHOEA WITH MUCUS RESECTION INCLUDING THE WITH TENESMUS LYMPH NODES. ARE THE MOST COMMON SYMPTOMS. ADENOCARCINOMA Common between the ages of 50-60. E/k: 2/1 They are usually caught at an advanced stage Prognosis depends on lymph node involvement. Radiotherapy and chemoterapy are not effective. It can also be seen in Peutz-jeghers syndrome or Crohn's disease. The prognosis of adenocarcinomas developing in the back ground of Crohn's disease is worse. SARCOMS LEIOMYASARCOMA IS MOST COMMON THE INCIDENCE IN MEN AND WOMEN IS EQUAL. THEY ARE EQUALLY SEEN IN JEJUNUM AND ILEUM. NEUROENDOCRİNE CARCİNOMA  Gastric neuroendocrine neoplasms  Duodenal neuroendocrine neoplasms  Pancreatic neuroendocrine neoplasms  Small intestinal neuroendocrine neoplasms (carcinoids)  Neuroendocrine neoplasms of the appendix  Colorectal neuroendocrine neoplasms  Neuroendocrine carcinomas  Mixed adenocarcinomas and neuroendocrine carcinomas  Neuroendocrine KC metastases CARCINOID TUMOUR S Description: All low grade tumours originating from all endocrine cell systems except C cells of the pancreas and thyroid are called carcinoid tumours.  REGIONS WITH THE HIGHEST DENSITY OF CARCINOID TUMOUR S DUODENUM, TERMINAL ILEUM AND APPENDIX. 60-70% OF CARCINOIDS ARE LOCALISED IN THE APPENDIX AND ILEUM. TUMOUR S ORIGINATING FROM THE MIDDLE INTESTINE (APPENDIX AND ILEUM) SECRETE SEROTONIN.  CARCINOID TUMOUR S AVERAGE AGE AT APPENDIX LOCALISATION 20-40 THE AVERAGE AGE OF OCCURRENCE IN THE SMALL INTESTINE IS 60 YEAR S. CLİNİC Primary Tumour Metastasis Hormonal Sekresyon Clinical symptoms CLİNİC Mesenteric Abdominal Pain Bowel Obstruction Ischaemia Cramp-like Intermittent Tumour or Paroxysmal Due to tumour or desmoplastic desmoplastic reaction reaction in the mesentery CARCINOID TUMOUR S ARE POTENTIALLY MALIGNANT TUMOUR S. LOCATION , LOCAL INTRAMURAL PENETRATION DEPTH AND ACCORDING TO TUMOUR DIAMETER PROGNOSIS VARIES. CARCİNOİD TUMOUR S MOST FREQUENTLY  MESENTERIC LYMPH NODES,  LIVER  LUNG AND  METASTASISE TO THE PERIOSTEUM.  TUMOUR MARKER S IDENTIFIED IN CARCINOID TUMOUR S CYTOKERATIN S-100 PROTEIN PREALBUMIN  CARCINOID TUMOUR S 75% are smaller than 1 cm and 2% of those smaller than 1 cm metastasise. 20% are between 1-2 cm and 50% of these metastasise. 5% are larger than 2 cm and 80-90% metastasise. CARCINOID TUMOUR S LOCATED IN THE COLON METASTASISE MOST FREQUENTLY (60 %) ILEAL CARCINOMAS 35% AND METASTASIS IS SEEN IN 3% OF CARCINOIDS LOCATED IN THE APPENDIX. METASTASES TO REGIONAL LYMPH NODES AND LIVER. Treatment depends on the localisation and diameter of the tumour and the presence or absence of metastases. Segmental resection for tumours smaller than 2 cm with negative regional lymph nodes, Tumours larger than 2 cm, multiple tumours and tumours with metastasis to regional lymph nodes require wide excision of the mesentery including the bowel segment and lymph nodes. CARCİNOİD SYNDROME  1954→ Thorson "Small bowel metastatic carcinoid tumour and unexpected symptoms and signs«  Serotonin  Carcinoid syndrome occurs with the release of serotonin into the systemic circulation instead of the portal circulation, such as in the case of a liver metastasis. CARCİNOİD SYNDROME Other vasoactive substances that are elevated; Biogenic amines (Histamine, Dopamine, Hydroxytryptophan etc.) Prostoglandins Carcinoid syndrome is associated with metastatic neuroendocrine tumours of the distal ileum in almost all cases. 95% due to KC metastasis 5% Primary tumour (retroperitoneal - ovarian) in localisation bypassing the portal circulation  Due to serotonin and other hormonal effects; Increased peristalsis Increased intraluminal fluid and electrolyte secretion Diarrhoea 73%  Due to the prolonged  Typically action of in the face, Carcinoid serotonin in neck and the circulatory Heart Disease (Hedinger Carcinoid Flushing upper chest system 65% areaIt can  The right syndrome) 10% Syndrome be triggered heart is mostly by exercise, affected stress,  Occurs in 25- alcohol and 50% of various patients with foods. carcinoid Bronchospasm 8% syndrome CARCINOID SYNDROME Hepatomegaly, Profuse Watery Diarrhoea, (Three of them are seen in 80% of patients) Paroxysmal Flushing Asthma-like Wheezing Attacks (25%), Right Heart Valve Disease (50%) , Abdominal pain, oedema, Pellegra-like lesions on skin and mucous membranes, It is characterised by malabsorption.  SEROTONIN 5 HT HISTAMIN KALLIKREIN BRADICIN INCREASED OSCILLATIONS HAVE BEEN SHOWN. BUT THE MAIN HORMONE THAT CAUSES THE SYNDROME IS SEROTONIN. THE MOST RELIABLE METHOD IN DIAGNOSIS IS THE DETERMINATION OF 5-HYDROXY INDOLE ACETIC ACID (5 HYPA), THE PRIMAR Y METABOLITE OF SEROTONIN IN URINE.. IN IMAGING OF CARCINOID TUMOUR S BT BARIUM PASSAGE RADIOGRAPHS AND MESENTERIC ANGIOGRAPHY IS USED. LIVER METASTASES ANGIOGRAPHY IS THE MOST SENSITIVE METHOD FOR VISUALISATION. For carcinoid tumours to cause carcinoid syndrome, the tumour must reach the systemic venous circulation. THIS IS ALSO POSSIBLE IN ADVANCED CASES. RETROPERTONEAL PARAVERTEBRAL VEIN INVASION , HEPATIC METASTASES OR THEY SUCCEED IF THE TUMOUR IS OUTSIDE THE INTESTINE. SHORT BOWEL SYNDROME 55  SHORT BOWEL SYNDROME It is a clinical picture that develops with the removal of a large part of the small intestine and there is not enough intestinal length for nutrition. Since the main function of the small intestine is digestion and absorption, these functions are lost in cases of extensive resection. Electrolytes, carbohydrates, AAs they are absorbed by active transport throughout the small intestine. Absorption of most nutrients is completed in the proximal small intestine. Iron, folate and Ca+2 are absorbed especially from the proximal small intestine, whereas bile salts and vitamin B12 are absorbed from the terminal ileum. THERE ARE 3 MAIN FACTOR S THAT AFFECT THE CHANCE AND QUALITY OF LIFE AFTER SMALL BOWEL RESECTION: 1- Length of the resected segment 2- Segment location 3- General condition of the patient before surgery  CAUSES OF WIDE SMALL BOWEL RESECTION LEADING TO SHORT BOWEL SYNDROME: RESECTION OF MORE THAN 80 PER CENT OF THE SMALL INTESTINE IS INCOMPATIBLE WITH LIFE. MESENTERIC VASCULAR OCCLUSION (MOST COMMON) CROHN'S DISEASES STRANGULATED HERNIAS MESENTERIC VESSEL INJURIES SMALL BOWEL VOLVULUS SMALL INTESTINE TUMOUR S RADIATION ENTERITIS Intestinal contents are kept isotonic in the jejunum and become more concentrated in the ileum. In the colon, especially water and salt absorption occurs. After jejunum resection, ileum and colon try to minimise the development of diarrhoea by absorbing increased fluid and electrolytes. However, after ileal resection, isotonic content of the jejunum and unabsorbed bile salts pass into the colon and cause severe diarrhoea. The reason for this diarrhoea is that bile salts destroy the membrane structure of colonic mucosa cells and prevent active Na transport.  Removal of more than 1 m of the ileum impairs the absorption of bile salts.  Absorption of fats is also impaired and steatorrhoea develops.  Gastric acid hypersecretion occurs with small bowel resection.  This is probably due to inhibition or elimination of a factor secreted from the small intestine that inhibits gastric acid secretion.  Gastric hypersecretion is transient.  Increased gastric secretions exacerbate diarrhoea by increasing the fluid-electrolyte load of the intestine.  In short bowel syndrome, gallstone formation increases 3-fold due to impaired enterohepatic circulation of bile salts. CLINICAL STAGES Phase 1 This is the period immediately after the operation. Fluid losses are at the highest level. Fluid electrolyte balance disorders are the most important cause of mortality in patients. It lasts an average of 3 weeks. Phase 2 Diarrhoea regresses. The patient is comfortable as long as there is no oral fluid and food intake. Diarrhoea occurs with meals. Intestinal adaptation occurs in this phase and lasts 3-6 months on average. Phase 3 Numerous nutritional and metabolic disorders occur in direct proportion to the length of intestine removed. Anaemia is common. Osteomalacia is present in 30% of patients. Hyperoxaluria, hypomagnesaemia, gallbladder and urinary system stones may be seen.