Access to Abdomen
This briefing document synthesizes clinical protocols and technical insights regarding abdominal access and the creation of pneumoperitoneum, based on established laparoscopic surgical standards.
Executive Summary
Effective laparoscopic surgery relies on safe abdominal access and the maintenance of a stable pneumoperitoneum. Surgeons primarily utilize two methods: the "closed" technique involving a Veress needle and the "open" technique utilizing a Hasson cannula. Critical takeaways include:
Rigorous Equipment Testing: Before use, insufflators and Veress needles must undergo specific pressure and flow tests to ensure safety mechanisms are functional.
Sequential Confirmation: For the closed technique, five distinct clinical tests must be performed in sequence to confirm the Veress needle is intraperitoneal before insufflation begins.
Technique Selection: While the closed technique is common, the open (Hasson) technique is the safest approach, particularly for patients with prior abdominal surgery and suspected adhesions.
Complication Vigilance: Immediate recognition of vascular or visceral injury is paramount. Major vascular injuries require immediate conversion to laparotomy, while abdominal wall bleeding can often be managed through tamponade or laparoscopic suturing.
I. Equipment Preparation and Verification
1. The Insufflator
The insufflator regulates the flow of Carbon Dioxide (CO2) to create the operative space. Before the procedure:
Gas Supply: Verify sufficient CO2 levels in the primary cylinder and ensure a spare tank is immediately available.
Internal Safety Check: Connect sterile tubing with an in-line filter. At high flow (>6 L/min), the intra-abdominal pressure should register 0 mmHg.
Pressure/Flow Shut-off Test: Set the flow to 1 L/min and kink the tubing. The pressure should rapidly rise to 30 mmHg while the flow indicator drops to zero. This confirms the safety shut-off mechanism is operational.
Flow Regulation: Test the Veress needle flow. Low flow should be 1 L/min; high flow should be 2–2.5 L/min. Pressure readings higher than 3 mmHg indicate a blockage in the needle or tubing.
2. The Veress Needle
Available in disposable (plastic, 14-gauge) or reusable (metal) formats, the needle features a spring-loaded blunt stylet that retracts upon resistance and springs forward once the peritoneum is breached.
Patency: Flush with saline to ensure no blockages.
Leak Check: Occlude the tip and push fluid under pressure.
Mechanical Function: Test the blunt tip against a hard surface to ensure it retracts easily and springs forward rapidly.
II. The "Closed" Technique (Veress Needle)
Umbilical Puncture and Insertion
The patient is placed in a 10–20° head-down position. The preferred site is the superior or inferior border of the umbilical ring, where the peritoneum is closest to the skin.
Insertion Angle: 45° caudal for asthenic patients; perpendicular for markedly obese patients.
Tactile Feedback: The surgeon should feel two "gives" as the needle traverses the fascia (linea alba) and then the peritoneum.
Confirmation of Intraperitoneal Placement
A 10-mL syringe with 5 mL of saline is used for a five-step confirmation sequence:
Insufflation Monitoring
Initial insufflation should begin at 1 L/min. The pressure must remain below 10 mmHg.
Signs of Success: Loss of liver dullness to percussion and symmetrical abdominal expansion.
Vagal Reaction: Monitor pulse and blood pressure; if the pulse falls, release CO2 and administer atropine.
Final Pressure: Once 1 L of CO2 is instilled, flow can be increased to maximum. A full pneumoperitoneum (12–15 mmHg) usually requires 3–6 L of CO2, resulting in an abdomen that sounds like a "ripe watermelon" upon percussion.
III. The "Open" Technique (Hasson Cannula)
The open technique is the safest method for patients with prior abdominal surgery, as it avoids blind needle or trocar insertion near potential adhesions.
Components and Mechanism
The Hasson cannula consists of a blunt-tipped obturator, a metal or plastic sheath, and a cone-shaped sleeve. The sleeve is secured into a formal fasciotomy and peritoneotomy using fascial sutures tied to struts on the cannula, creating an airtight seal.
Procedure Highlights
Incision: A 2–3-cm transverse incision is made at the entry site.
Dissection: Subcutaneous tissue is cleared, and the fascia and peritoneum are incised under direct vision.
Digital Palpation: The surgeon inserts a finger to confirm entry and sweep away any local adhesions.
Securing: Two #0 absorbable sutures are placed on the fascial edges and wound around the cannula struts to fix the device in place.
IV. Alternate Sites and Trocar Placement
Site Selection in the Operated Abdomen
Prior scars mandate alternate entry points lateral to the rectus muscles to avoid the inferior epigastric vessels.
Lower Midline Scars: Use the right or left upper quadrants.
Upper Midline Scars: Use the right lower quadrant (near McBurney's point).
Organ Avoidance: Percuss for the liver and spleen; decompress the stomach and bladder before insertion.
Trocar Insertion
Trocars (sharp, shielded, or optical) are inserted after the pneumoperitoneum is established.
Blind Entry: Provide resistance by lifting the abdominal wall. Aim toward the pelvis in slender patients.
Optical Trocars: Allow visual advancement through tissue layers using a 0° laparoscope.
Confirmation: Egress of CO2 upon opening the stopcock confirms entry.
V. Management of Complications
1. Abdominal Wall Bleeding
Usually involving the inferior epigastric artery, this manifests as blood dripping from a port or hematoma formation.
Management: Use the trocar to cantilever into each quadrant to identify where pressure stops the flow. Control via laparoscopic suture ligation or tamponade with a Foley catheter.
2. Visceral Injury
Veress Needle Puncture: Small-caliber needle injuries to the bowel are often managed by simple removal and repuncture.
Trocar Laceration: Requires active intervention, such as laparoscopic repair, formal laparotomy, or minilaparotomy to exteriorize and repair the segment.
3. Major Vascular Injury
Injury to the aorta, vena cava, or iliac vessels is a surgical emergency.
Recognition: Bloody fluid in the Veress needle or a "rush of blood" through a trocar accompanied by hypotension.
Management: If a trocar is involved, leave it in place to act as a tamponade and mark the site. Immediate laparotomy is mandatory to repair the vessel.
