Establishment Of Pneumoperitoneum And The Closed Veress Needle Technique: A Standardized Step-by-Step Guide

https://en.wikipedia.org/wiki/Veress_needle

Overview

Although the indications for gasless laparoscopy have expanded in recent years, the vast majority of laparoscopic procedures still rely on artificial pneumoperitoneum to achieve adequate surgical exposure.​ In gas laparoscopy, the establishment of pneumoperitoneum is the first and foundational step​ that determines the success of the entire operation.

Before initiating pneumoperitoneum, the surgeon must complete two indispensable preparatory steps:

Instrument check: Routinely verify that all lumens of the Veress needle are patent and that the spring-loaded mechanism functions properly.

Individualized assessment: Inspect the lower abdominal wall-particularly the periumbilical region-for surgical scars and abnormally coursing superficial vessels. Integrate preoperative ultrasound findings regarding abdominal wall thickness and supra-pubic distance​ to comprehensively determine the Veress needle's insertion site, direction, and estimated depth.

I. Selection of the Puncture Site

1.1 Why Is the Umbilicus the Preferred Site?

The puncture site for pneumoperitoneum typically coincides with the location of the primary trocar. The umbilicus, as a natural scar of the abdominal wall, is the thinnest area with the fewest blood vessels. It contains virtually no subcutaneous fat or muscle tissue, and its anatomical vascular network is sparse. As a result, the risk of both intraoperative and postoperative bleeding is minimal. Furthermore, an umbilical incision heals with little to no visible scarring, offering excellent cosmetic outcomes.

In the vast majority of laparoscopic procedures, a 10 mm incision​ is made at the umbilical center or slightly above/below it.​ A thorough understanding of the layered anatomy at this level is essential for the safe placement of the primary trocar.

1.2 Adjusting the Insertion Angle According to BMI

The thickness of the umbilical tissue varies significantly across patients of different weights. The Veress needle insertion angle must be adjusted accordingly:

1.3 Site Adjustments for Special Circumstances

Infected umbilicus or deep previous scarring: The puncture should be made at the inferior umbilical edge.

Large pelvic mass: If the pelvis is occupied by a large tumor, the puncture site should be shifted above the umbilicus.

Additional accessory ports: Bilateral subcostal regions, bilateral iliac fossae, or McBurney's point - selected flexibly based on the specific surgical procedure.

History of prior abdominal surgery: As a general principle, the puncture site should be ≥ 3 cm away from the original scar​ to avoid potentially adherent bowel.

II. Design Principles and Puncture Technique of the Veress Needle

2.1 The Veress Needle: A Classic Design Spanning Over Eight Decades

Since its invention in 1938 by Hungarian surgeon János Veress, the closed Veress needle technique has become one of the most frequently employed methods for establishing pneumoperitoneum.​ Its ingenious safety design includes:

Blunt-tipped, hollow stylet with lateral side-ports: Allows insufflation, irrigation, and aspiration through the needle hub; the side-ports also enable multi-directional operation.

Spring-loaded safety mechanism at the base: When resistance is encountered during abdominal wall penetration, the stylet retracts into the sharp outer cannula. Once the cannula tip breaches the peritoneum and enters the abdominal cavity, resistance disappears and the spring deploys the blunt stylet forward. This mechanism effectively prevents the sharp cannula tip from inadvertently injuring intra-abdominal viscera.

2.2 Mandatory Pre-Puncture Checks

Before each use, the following checks must be performed - make them an indispensable part of your routine:

2.3 Standardized Puncture Procedure

Step 1: Umbilical Cleaning and Disinfection

Thoroughly clean the umbilical fossa with antiseptic gauze to remove accumulated debris and sebum. This often-overlooked step is critical for preventing postoperative wound infection.

Step 2: Skin Incision

Use skin forceps to grasp both sides of the umbilical edge, and make a ~1 cm midline incision​ at the umbilicus using a scalpel.

Step 3: Elevating the Abdominal Wall

Remove the skin forceps and replace them with towel clamps (Backhaus clamps)​ applied to both sides of the umbilical skin, pulling cephalad. This increases the distance between the anterior abdominal wall and the underlying omentum and bowel, significantly reducing the risk of puncture injury.

Step 4: Veress Needle Insertion

The surgeon holds the Veress needle in the right hand and advances it slowly with a rotational motion, perpendicular to the abdominal wall (or at the angle specified above). When the needle passes through the anterior rectus sheath and peritoneum, a distinct "loss of resistance" or "pop"​ is felt. Stop advancing immediately at this point.

Alternative common technique: Some surgeons prefer to grasp the abdominal wall with the left hand and directly insert the Veress needle with the right hand using a twisting motion. Both methods are valid; beginners may choose the one that provides better tactile feedback.

III. Objective Indicators for Confirming Veress Needle Entry into the Peritoneal Cavity

This is the most critical verification step​ of the entire procedure. Even when a loss of resistance is felt, confirmation through the following methods is mandatory.

3.1 Basic Confirmation Methods

3.2 Advanced Verification Methods (When Loss of Resistance Is Unclear)

❶ Aspiration Test

Connect a syringe filled with normal saline to the Veress needle.

First, aspirate: If no blood or bowel contents are returned, inject 5–10 ml of saline.

Interpretation:

✅ Smooth injection with inability to aspirate → Needle tip is correctly in the peritoneal cavity.

❌ Aspiration returns blood or bowel contents → Injury to bowel or major vessel; immediate assessment for conversion to open surgery is required.

❌ Heavy or pulsatile bleeding → Immediate conversion to open laparotomy is mandatory.

❷ Drop Test

Attach a syringe barrel without a plunger to the needle hub, or place a few drops of saline directly onto the hub. If the fluid is rapidly drawn into the abdomen​ by negative pressure, the needle tip is correctly positioned.

❸ Early Insufflation Test - The Gold Standard Every Beginner Must Master

The above tests only confirm entry into a "cavity," but cannot definitively confirm that this cavity is the peritoneal cavity​ (it could be an intermuscular or preperitoneal space). The early insufflation test provides the final confirmation:

Connect the insufflation tubing and set the safety pressure limit.

Begin insufflation at a low flow rate of 1 L/min.

Closely observe the combination of pressure and flow readings:

IV. Insufflation Parameter Settings and Intra-Insufflation Monitoring

4.1 Parameter Settings on the Insufflator

Before insufflation, the following key parameters must be preset on the insufflator:

Physiological protection note: The initial slow-insufflation phase is critical. If CO₂ floods the abdominal cavity too rapidly, causing an abrupt increase in intra-abdominal pressure, it may compress the inferior vena cava, reduce venous return, and adversely affect cardiopulmonary function.

4.2 Recognizing Abnormalities During Insufflation

During insufflation, if the insufflator reading shows that intra-abdominal pressure persistently exceeds 13 mmHg, this indicates the following possibilities:

The Veress needle's side-ports are obstructed by tissue;

The needle tip has shifted position (e.g., pressed against the abdominal wall or embedded in the omentum);

There is an obstruction in the insufflation tubing system.

Insufflation must be stopped immediately, and the needle position should be adjusted or re-punctured.

V. Conclusion

The Veress needle closed technique offers the advantages of simplicity and time efficiency, making it the most widely used method for establishing pneumoperitoneum in laparoscopic surgery. However, its inherent drawback is the potential for blind puncture-related injuries to blood vessels or viscera.​ Therefore, beginners must develop a thorough familiarity with the entire process - from pre-puncture instrument checks and individualized site selection, to standardized insertion technique, multi-dimensional position verification, and precise insufflation parameter control - in order to perform safe and confident operations in clinical practice.