Anastomosis Lab
Logistics and Sponsor:
Held in the 12th floor simulation lab.
Sponsor: Ethicon
EPA Addressed:
#15 Evaluate and manage a patient with a small bowel obstruction.
Goals and Objectives
Goals:
Develop an understanding of the evaluation and management of patients presenting with small bowel obstruction (SBO).
Gain proficiency in performing bowel resection and anastomosis using both hand-sewn and stapled techniques.
Objectives:
Operative Management:
Identify indications for surgical intervention in patients with SBO.
Demonstrate preoperative planning and patient optimization.
Perform a bowel resection and anastomosis using hand-sewn and stapled techniques.
Understand the principles and techniques for both hand-sewn and stapled bowel anastomosis.
Technical Skills Development:
Gain familiarity with sponsored staplers and sutures, understanding their indications and usage.
Perform bowel resection and anastomosis on simulation models using hand-sewn and stapled techniques.
Clinical Scenarios
Scenario 1:
Mr. Johnson, a 65-year-old male, presents to the emergency department with a 2-day history of obstipation, abdominal pain, and vomiting. He has a significant medical history of an open sigmoidectomy for perforated diverticulitis performed 5 years ago. His current symptoms began with cramping abdominal pain that progressed to constant pain, accompanied by nausea and vomiting. He reports no flatus or bowel movements in the past 48 hours.
Scenario 2:
Ms. Lee, a 58-year-old female, presents to the clinic with a 3-month history of intermittent abdominal pain, bloating, and weight loss. She also reports occasional episodes of nausea and vomiting. Her past medical history is unremarkable and she has never had surgery.
Scenario 3:
Mr. Davis, a 52-year-old male, presents with a 1-week history of intermittent, cramping abdominal pain, that worsened overnight and now is associated with severe abdominal pain and nausea. He had a Roux-en-Y gastric bypass (RYGB) 3 years ago.
Instructional Resources
Small Bowel Obstruction (SBO) - The Operative Review Of Surgery
Bowel Resection an Anastomosis - The Operative Review Of Surgery
Intestinal Anastomosis: Practice Essentials, Background, Indications (medscape.com)
Zollinger’s Atlas of Surgical Operations, 11e (use access surgery through the UA Library)
Chapters 48-50 and 59
Linear Stapler Use
Stapler Tissue Compression
Mock Orals
Scenarios are made up, and any similarity to real cases is by coincidence only.
Scenario 1:
Examiner:
"Mr. Johnson, a 65-year-old male, presents with a 2-day history of obstipation, abdominal pain, and vomiting. He has a history of an open sigmoidectomy for perforated diverticulitis performed 5 years ago followed by ostomy reversal. He is otherwise healthy and takes no medications. His vitals are: HR 100, Blood pressure 105/85, SpO2 95%, temperature 37.5 C. On examination, he has distension, diffuse tenderness without rebound or guarding, and no bowel sounds. The ER had ordered an abdominal X-ray that shows multiple dilated loops of small bowel with air-fluid levels.
Examinee:
"Based on his surgical history and presentation, I am worried about a small bowel obstruction. Less likely it could be constipation, a large bowel obstruction, or an ileus. As the most common causes of bowel obstruction include adhesions, hernias, and malignancy, I would ensure I took a good personal and family history and checked for hernias on exam. As he doesn't have peritonitis, I would start by working him up with imaging and lab studies. I would get a CBC, BMP, and a lactic acid to assess for and inflammation, mal-perfusion, or electrolyte derangements from his vomiting. Since he is still nauseated and his imaging is suggestive of proximal distension, I would decompress the patient with a nasogastric tube, and I would start a 1 Liter of crystalloid for resuscitation. Additionally, I would want to gain more information about his previous surgeries and review the pathology."
Examiner:
"He doesn't know his family history as he is adopted, but he knows he had a colonoscopy prior to his reversal that showed no cancer and his final pathology form his sigmoidectomy just showed diverticulitis. He has no hernias on exam. After nasogastric decompression, the patient feels a lot better with improving nausea and abdominal pain. The CBC and lactic are within normal limits, and the BMP shows a Potassium of 3.2, a Chloride of 95, and a Creatinine of 1.5. His baseline is 0.7. The surgical records are being requested, but they are from out of state and may take some time to get."
Examinee:
"I'm currently working the patient up for a small bowel obstruction, so I would get a CT scan with IV and PO contrast to assess for transition points, bowel integrity, masses, and for potential pre-operative planning. Though the data is leaning away from IV contrast causing worsening AKI, I would still pre-hydrate the patient with another 1 L of crystalloid prior to the CT scan since he has an AKI. I suspect the AKI is from a pre-renal cause secondary to dehydration, but I would still send urine electrolytes to assess his FeNa."
Examiner:
"A CT scan reveals a transition point in the left lower quadrant consistent with adhesive small bowel obstruction. No masses are seen, and the bowel appears to be enhancing without any free fluid. His FeNA returns as <1%."
Examinee:
"This appears to be adhesive in nature, and I don't have any signs of bowel compromise at this time. I would initially manage him conservatively with continued decompression, serial abdominal exams, and resuscitation to treat his electrolyte abnormalities and pre-renal AKI. I would get timed follow up KUBs to assess for contrast progression. I would counsel the patient that the majority of adhesive small bowel obstructions resolve with conservative management, but if the contrast does not progress, or if he gets clinically worse, that we would need to have a low threshold to proceed with surgery."
Examiner:
"You successfully correct the electrolytes and his Creatinine starts to improve. Though he initially felt better after decompression, a few hours later he starts to have worsening abdominal pain and increased nasogastric tube output. Follow up imaging has shown no progress of the previously administered oral contrast."
Examinee:
"Given the worsening of symptoms and persistent obstruction, I would proceed with surgical intervention. I would review his pre-operative CT to look for areas of safe abdominal entry and take the patient for a diagnostic laparoscopy with Hasson entry and possible exploratory laparotomy."
Examiner:
"You are able to safely gain Hasson access in the upper abdomen. How would you proceed?"
Examinee:
"If I had enough working room, I would place two additional ports under direct vision to run the small bowel from the terminal ileum proximally to identify the transition point. If I was unable to gain adequate visualization or there was significant adhesive disease precluding safe laparoscopy, I would convert to open surgery.
Examiner:
"You find moderate thin adhesions through the abdomen but they are easily separated. There is a dense scar band in the left lower quadrant causing an obstruction in the small bowel to the anterior abdominal wall."
Examinee:
"I would carefully dissect and lyse the dense scar band causing the obstruction. After releasing the adhesions, I would inspect the entire length of the small bowel for any additional points of obstruction or compromised bowel. If the bowel appears viable and there are no other adhesions causing obstruction, I ensure meticulous hemostasis before closing."
Examiner:
"The bowel appears viable, and no resection is needed. What are your postoperative considerations for this patient?"
Examinee:
"Postoperatively, I would closely monitor the patient for signs of infection, such as fever or elevated white blood cell count, and ensure adequate pain control with appropriate analgesics. I would gradually advance his diet starting from clears, as he is at risk for a post operative ileus. I would also encourage early mobilization to prevent complications such as deep vein thrombosis and pulmonary embolism."
Scenario 2:
Examiner:
"Ms. Lee, a 58-year-old female, presents with a 3-month history of intermittent abdominal pain, bloating, and weight loss now progressing over the last two days to nausea and vomiting. She can't keep any food or water down and hasn't had a bowel movement or passed gas in two days. She denies ever having this problem before. She has never had surgery, takes no medications, and has no allergies."
Examinee:
"Her presentation is concerning for a gastrointestinal obstruction. The progressive symptoms and lack of a surgical history are concerning for malignancy, though less likely an intermittent obstruction such as a hernia. I would inquire more about her personal and family cancer history and social history to assess her cancer risk. I would ask if she has ever had a colonoscopy or EGD, and if so, what the reports showed. I would want to get a full set of vitals. I would perform a focused examination including a cardiopulmonary exam and an abdominal exam with care to look for hernias, scars, or masses. If she was still actively throwing up and bloated, I would place an NG tube for decompression. I am worried about dehydration and electrolyte abnormalities, so I would ensure IV access for crystalloid resuscitation and send labs including a CBC, CMP, and lactic acid."
Examiner:
"She had a colonoscopy when she turned 45 years old and one when she was 55 years old, and she was told they were clean and to return in 10 years. She denies ever having cancer or and familial cancers. Her vitals are: Heart rate 125, Blood pressures 100/85, SpO2% of 97%, and a temperature of 37.5 C. Her cardiopulmonary exam is significant for tachycardia, and her abdomen is distended in the epigastrium with tympany and tenderness, but no rebound or guarding. After NG decompression she feels significant relief. Her CBC shows a white blood cell count of 13, a hemoglobin of 15, a potassium of 3.1, a chloride of 91, and a creatinine of 1.7. Her lactic acid is 3.2."
Examinee:
"Though her white count and lactic are up, I am suspicious this is more related to dehydration than it is bowel compromise. I would perform electrolyte replacement and fluid resuscitation with 2 liters of NS due to her chloride losses from emesis. I would order urine electrolytes to calculate a FeNa as well to ensure the AKI is pre-renal in nature. I would trend her abdominal exam and CBC and lactic response to fluid as well. As I do not have a cause for the bowel obstruction at this time, I would order a CT scan with IV contrast and PO contrast if she were able to tolerate it."
Examiner:
"The CT scan was done only with IV contrast due to patient intolerance to the PO contrast. It reveals a 4 cm mass in the mid-jejunum with proximal small bowel dilation and air fluid levels. The mass is smoothly contoured, hypodense, and immediately adjacent to the gut lumen. There is an internal focus of necrosis. There is no surrounding lymphadenopathy, and no other masses or lesions were otherwise noted."
Examinee:
"This is concerning for a jejunal tumor, most likely a GIST or a Leiomyoma and less likely an adenocarcinoma or Leiomyosarcoma. Based on the CT findings and obstruction, I am more concerned for a Leiomyoma, and I would discuss the imaging findings with a radiologist to see if they had further insight into the diagnosis. Ideally, I would want an endoscopic biopsy of a gastrointestinal tumor, but since the patient is obstructed and there are no signs of spread, I would recommend the patient undergo surgical resection of the tumor with the involved bowel segment.
Examiner:
"Your radiologist colleague agrees that it is suspicious for a leiomyoma."
Examinee:
"Given the working diagnosis of a jejunal leiomyoma causing obstruction, I would plan for an urgent small bowel resection after preoperative optimization that would include nutritional support, electrolyte correction, and a thorough discussion with the patient regarding the surgical procedure, risks, and postoperative care."
Examiner:
"Describe your operative approach for this patient."
Examinee:
"Just in case this is a malignancy, I would approach it open. I would perform a midline laparotomy to access the abdomen and run the bowel completely from the terminal ileum proximally to the ligament of Treitz to assess the bowel viability and to identify the transition point and the mass. After identifying the mass I would assess for any lymphadenopathy or liver lesions. Assuming there are none, I would resect the segment of the bowel containing the tumor with 5 cm margins. I would then perform a hand-sewn, two-layer end-to-end anastomosis to restore bowel continuity with care to ensure mucosal inversion. I would close the mesenteric defect. The abdomen would be irrigated and inspected for hemostasis before closing the incision in layers."
Examiner:
"She recovers well and sees in you clinic for a wound check. Her pathology returns and is negative for CD117, positive for CD34, and negative for PKC-theta. She has less than 2 mitoses per high power field and the margins are negative. The patient asks what this means and if she has cancer."
Examinee:
"I would counsel the patient that the markers confirm that she had a benign Leiomyoma and not a malignant Leiomyosarcoma. No further adjuvant treatment is required, but occasionally local recurrence can occur so I would counsel her on remaining aware of the signs and symptoms of local recurrence that would require further evaluation."
Scenario 3:
Examiner:
"Mr. Davis, a 52-year-old male, presents with a 1-week history of intermittent, cramping abdominal pain that worsened overnight and was associated with nausea. He had a Roux-en-Y gastric bypass (RYGB) 3 years ago and his BMI dropped from 45 to 37 since then. On examination, he appears to be in moderate distress. His vital signs are blood pressure 125/80 mmHg, heart rate 90 bpm, respiratory rate 18 breaths per minute, temperature 37.0°C (98.6°F), and oxygen saturation 98% on room air. Abdominal examination reveals mild distension and tenderness in the upper abdomen without rebound tenderness or guarding.
Examinee:
Given the patient's history of gastrib bypass surgery and presentation suggestive of gastrointestinal obstruction, I am highly concerned about an internal hernia. The differential also includes marginal ulceration, afferent limb syndrome, and other post-bariatric syndromes. I would want to get lab studies to include a CBC, CMP, and lactic acid to assess for inflammation, bleeding, electrolyte abnormalities, and ischemia. I would also order a CT scan of the abdomen and pelvis with IV contrast to assess for a transition point, mesenteric swirling, free air, or other pathology.
Examiner:
"Labs are within normal limits. A CT scan reveals swirling of the mesenteric vessels and dilated small bowel loops."
Examinee:
"This confirms my suspicion for an internal hernia either through a mesenteric defect or adhesive band. This constitutes a surgical emergency. I would prepare the patient for an exploratory laparoscopy. I would appropriately secure the patient to the bed with appropriate padding and a foot board, and I would ensure pre-operative administration of Lovenox for DVT prophylaxis as well as pre-operative SCIP antibiotics. After gaining access, I would run the bowel starting from the terminal ileum."
Examiner:
"During the laparoscopy, you find an antecolic roux limb and an internal hernia through pseudo-Petersen's space causing a closed loop obstruction."
Examinee:
"I would reduce the herniated bowel loops carefully and assess their viability. If the bowel is viable, I would proceed to close the hernia defect with non-absorbable sutures to prevent recurrence. If any bowel appeared ischemic or non-viable, I would confirm with ICG administration and fluorescence angiography and perform a resection of the affected segment followed by an anastomosis. I would also inspect other common sites of internal hernia, such as the mesenteric defect at the jejunojejunostomy."
Examiner:
"The herniated bowel has a small segment of necrotic bowel."
Examinee:
"I would perform an intracorporeal resection and side-to-side functional end-to-end anastomosis with endo-GIA staplers. I would place a crotch stich and ensure the anastomosis is healthy, hemostatic, and patent. I would pull the bowel segment out in a bag if possible or through a wound protector if not. I would close the port I removed the specimen from with an endo fascial closure device if it had to be dilated for removal."
Examiner:
"The patient recovers well initially but develops sudden onset shortness of breath, chest pain, and tachycardia on postoperative day 2."
Examinee:
"The differential diagnosis includes pulmonary embolism (PE), myocardial infarction, pneumonia, and atelectasis. Given the sudden onset of symptoms and the patient's recent surgery, pulmonary embolism is highly concerning. I would start with getting new vitals and performing a thorough physical examination, including a cardiopulmonary exam, an abdominal exam, checking for signs of deep vein thrombosis (DVT) in the lower extremities, and using bedside ultrasound to qualitatively assess the heart and lungs. I would obtain an new set of labs to include a CBC, CMP, lactic acid, and troponin. I would get an electrocardiogram (ECG) and order an urgent CT pulmonary angiogram (CTPA) to assess for a PE. In the meantime, I would administer supplemental oxygen and initiate anticoagulation with intravenous heparin if I saw no signs of post operative bleeding."
Examiner:
"The patients vitals are as follows: a heart rate of 130, a blood pressure of 135/85, a SpO2 of 91% on 6L NC, and a temperature of 37.8 C. The EKG shows sinus tachycardia without ST changes. Your bedside POCUS shows tachycardia without any obvious wall motion abnormalities or any significant right ventricular distension. The TAPSE is normal. The CT pulmonary angiogram confirms the presence of a pulmonary embolism."
Examinee:
"With the confirmed diagnosis of PE, I would want a formal ECHO to confirm there is no right heart strain. I would continue the patient on anticoagulation therapy, starting with a weight-based heparin infusion and transitioning to a long-term anticoagulant, such as warfarin or a direct oral anticoagulant (DOAC), once the patient is stable. I would monitor the patient closely for signs of bleeding, given the recent surgery."
Checklists
Identification of Indications for Surgical Intervention:
Discuss the rationale for surgical intervention based on the simulated patient scenario.
Hand-Sewn Bowel Anastomosis:
Perform a bowel resection on the simulation model.
Create a hand-sewn, two-layer end-to-end anastomosis using appropriate sutures.
Ensure a tension-free and hemostatic anastomosis.
Confirm patency of the anastomosis by checking for leaks and ensuring proper alignment.
Stapled Bowel Anastomosis:
Gain familiarity with the sponsored staplers and sutures, including their indications and usage.
Perform a bowel resection on the simulation model.
Create a stapled end-to-end anastomosis using the sponsored staplers.
Ensure a tension-free and hemostatic anastomosis.
Confirm patency of the anastomosis by checking for leaks and ensuring proper alignment.