Overview
Definition:
The purse-string device is a surgical tool used to create a pursed opening in the bowel or other hollow viscus, facilitating precise circular stapler anastomosis
It acts as a guide and tensioning mechanism, ensuring proper apposition of staple line and mucosal edges.
Epidemiology:
The application of purse-string techniques for stapled anastomosis is widespread in various surgical specialties, particularly gastrointestinal and colorectal surgery, with an estimated 70-90% of bowel resections utilizing some form of stapled anastomosis
Incidence of complications like leaks varies, influencing technique selection.
Clinical Significance:
Accurate and secure anastomosis is paramount to prevent leaks and ensure successful patient outcomes post-resection
The purse-string device aids in achieving this by simplifying the precise placement of the circular stapler, reducing tension, and minimizing the risk of mucosal prolapse or uneven staple line formation
Its efficient use is crucial for resident competency and patient safety.
Indications
Primary Indications:
Construction of colorectal anastomosis following low anterior resections
Esophago-gastric anastomosis
Intestinal side-to-side or end-to-end anastomosis
Pancreaticoduodenectomy with pancreaticojejunostomy
Biliary enteric anastomosis.
Specific Scenarios:
Tight or friable bowel requiring careful handling
Situations where accurate mucosal apposition is critical for leak prevention
When using specific stapler models that benefit from a pursed annular opening
Minimizing intra-abdominal contamination during the anastomosis.
Contraindications:
Severe inflammatory bowel disease with active transmural inflammation affecting tissue integrity
Extensive tumor infiltration near the proposed anastomosis site compromising tissue strength
Significant disparity in lumen size that cannot be adequately managed by purse-string technique or stapler selection.
Preoperative Preparation
Patient Assessment:
Evaluation of nutritional status, comorbidities, and anticoagulation
Optimization of fluid and electrolyte balance
Review of imaging for tumor extent and proximity to viable bowel margins.
Surgical Planning:
Selection of appropriate stapler size based on bowel diameter
Choice of purse-string material (e.g., monofilament suture)
Planning of bowel mobilization and preparation of the anastomotic site
Ensuring availability of necessary instruments, including the purse-string device and stapler.
Anesthesia And Prophylaxis:
General anesthesia with appropriate monitoring
Prophylactic antibiotics, typically broad-spectrum covering gram-negative and anaerobic organisms
Deep vein thrombosis prophylaxis as per institutional protocol.
Procedure Steps
Bowel Mobilization And Preparation:
Adequate mobilization of the bowel segments to be anastomosed
Creation of appropriate openings (enterotomies) in each segment for stapler insertion
Removal of any diseased or avascular tissue.
Purse String Insertion:
Using a monofilament suture (e.g., 3-0 or 4-0 Prolene), the purse-string suture is meticulously placed in a continuous or interrupted fashion around the circumference of the enterotomy, about 2-5 mm from the cut edge
The ends are left long for later traction.
Stapler Placement And Firing:
The anvil of the circular stapler is introduced into one lumen, and the cartridge containing the staples is introduced into the other
The purse-string suture is then tied firmly around the shaft of the anvil, creating the pursed opening and drawing the mucosa over the anvil head
Gentle traction on the purse-string sutures secures the bowel to the stapler
The stapler is then fired, creating a circular anastomosis and dividing excess tissue.
Confirmation And Reinforcement:
Inspection of the staple line for hemostasis and integrity
Checking for any mucosal gaps or tissue compromise
In some cases, the purse-string suture may be used to further reinforce the anastomosis or to close the enterotomy sites used for stapler insertion
A leak test (e.g., air insufflation or saline submersion) may be performed.
Postoperative Care
Monitoring:
Close monitoring of vital signs, urine output, and abdominal examination for distension or tenderness
Pain management
Assessment for signs of ileus or infection.
Fluid And Nutrition:
Intravenous fluid resuscitation
Early initiation of enteral feeding (often within 24-48 hours postoperatively, depending on anastomotic site and surgeon preference) to promote gut healing
Nasogastric tube decompression may be required if significant ileus develops.
Ambulation And Discharge:
Encouraging early ambulation to prevent complications such as pneumonia and deep vein thrombosis
Gradual progression of diet
Discharge planning focusing on wound care, activity restrictions, and follow-up appointments
Education on warning signs of complications.
Complications
Early Complications:
Anastomotic leak: The most feared complication, leading to peritonitis, sepsis, and potential reoperation
Stapler malfunction: Failure to fire, incomplete staple formation, or tissue entrapment
Bleeding: From the staple line or surrounding tissues
Ileus: Delayed return of bowel function.
Late Complications:
Anastomotic stricture: Narrowing of the anastomosis leading to obstructive symptoms
Internal hernia formation at the site of an unrepaired mesenteric defect
Fecal fistula formation
Adhesions and small bowel obstruction.
Prevention Strategies:
Meticulous surgical technique and proper stapler selection and use
Careful bowel preparation and handling
Ensuring adequate blood supply to the anastomotic edges
Performing leak tests when indicated
Close postoperative monitoring and early intervention for any suspected complication
Adequate mobilization to avoid tension on the anastomosis.
Key Points
Exam Focus:
Understanding the principle of purse-string closure for accurate stapler seating
Differentiating indications for purse-string versus other anastomosis techniques
Knowing the common complications and their management
Stapler sizes and their relation to lumen diameter.
Clinical Pearls:
Always use monofilament suture for purse-string to avoid tissue drag
Ensure even placement of the suture 2-5 mm from the cut edge
Gentle but firm traction on the purse-string is key for correct anvil capture
Perform a functional leak test if any doubt about anastomosis integrity.
Common Mistakes:
Suture placed too close to the edge, leading to tissue avulsion
Inadequate pursing of the lumen, causing stapler malalignment
Over-tightening the purse-string, potentially strangulating tissue
Not performing a leak test when indicated, leading to delayed diagnosis of a leak
Improper stapler size selection.