Overview
Definition:
Port placement refers to the strategic positioning of trocars or ports within the body cavity to facilitate the introduction of surgical instruments and a camera during minimally invasive procedures
Optimal placement is crucial for achieving adequate triangulation, ergonomic instrument manipulation, and a clear surgical field, thereby minimizing tissue trauma and enabling complex maneuvers.
Epidemiology:
Minimally invasive surgery (MIS) has become the standard of care for a vast array of surgical procedures globally
The incidence of MIS varies by procedure, with laparoscopic cholecystectomy being one of the most common, performed in millions annually
Growth in robotic-assisted surgery further increases the importance of understanding port placement principles.
Clinical Significance:
Proper port placement is paramount for successful MIS outcomes
Poor placement can lead to reduced dexterity, instrument collisions, inadequate visualization, increased operative time, and a higher risk of complications such as iatrogenic injuries
It directly impacts surgical efficiency, patient safety, and the ability to complete complex dissections and reconstructions.
General Principles
Triangulation:
The principle of triangulation involves placing three ports in a geometric arrangement that allows instruments to form a functional triangle with the target anatomy
This enables precise manipulation and dissection by allowing instruments to act as a fulcrum.
Ergonomics:
Instrument handles should ideally be aligned with the surgeon's line of sight and the surgeon's dominant hand should be positioned to facilitate natural movements and reduce fatigue
Ports should be spaced appropriately to avoid "windmilling" or "grasshopper" effect.
Access And Visualization:
Ports should provide unobstructed access to the operative field and allow the camera to provide a clear, wide view of the anatomy
Consideration must be given to the working length of instruments and the need for retraction.
Avoidance Of Injury:
Strategic placement minimizes the risk of injuring underlying organs, major blood vessels, and nerves
Critical structures should be visualized before port insertion whenever possible.
Procedure Specific Considerations:
The specific anatomy being operated on, the instruments used, and the surgeon's preferred approach dictate optimal port positioning for each operation.
Laparoscopic Abdominal Surgery
Cholecystectomy:
Typically, a four-port technique is used: a supraumbilical or infraumbilical umbilical port for the camera, a port at the right subcostal margin for retraction of the gallbladder, a port in the right upper quadrant (e.g., anterior axillary line) for dissection, and a port in the epigastrium for retraction of the liver or dissection
Modifications exist, including single-incision techniques.
Appendectomy:
Commonly employs three or four ports: umbilical port for the camera, a suprapubic or suprapubic midline port for grasping the appendix, and lateral ports (e.g., left iliac fossa, right flank) for dissection and ligation.
Hernia Repair Tapp:
Requires a port within the optical trocar at the umbilicus for the camera and instruments
Additional ports are placed for dissection of the peritoneum and placement of the mesh, typically in the lower abdomen, laterally and medially to the hernia.
Colorectal Surgery:
Varies greatly by procedure
For low anterior resection, ports are often placed in the umbilical, suprapubic midline, left iliac fossa, and right flank
Strategic placement ensures access to the mesorectum and pelvic dissection planes.
Gastric Bypass:
Typically utilizes a five-port technique: umbilical camera port, epigastric port for retraction, left upper quadrant port for jejunal dissection, and two other ports in the mid-abdomen for manipulation and anastomosis.
Laparoscopic Gynecological Surgery
Hysterectomy:
A standard approach involves a primary umbilical port for the camera and additional ports in the lower abdomen (suprapubic, bilateral lower quadrants) for manipulation, dissection, and ligation of vascular pedicles.
Oophorectomy Cystectomy:
Often utilizes a similar port configuration to hysterectomy, with ports placed to provide adequate access to the adnexa for safe removal of ovarian masses or the entire ovary.
Tubal Ligation:
Can be performed with as few as two ports, with one for the camera and one for instrument manipulation, typically placed in the lower abdomen.
Laparoscopic Urological Surgery
Nephrectomy:
Standard port placement includes an umbilical camera port, with working ports placed in the flanks, anterior axillary lines, and suprapubic region to allow dissection of the kidney and vascular pedicles.
Prostatectomy:
Robotic prostatectomy typically uses a supra-pubic port for the camera and five accessory robotic ports placed in a specific pattern around the pelvis to allow for precise dissection and suturing of the prostatic fossa and bladder neck.
Robotic Surgery Considerations
Docking And Reach:
The robotic system requires specific docking angles and sufficient reach from the robotic arms
Port placement must account for the robot's geometry and instrument articulation, often requiring wider port spacing than laparoscopic surgery.
Instrument Collision:
With multiple robotic arms, the risk of instrument collision is higher
Ports are strategically placed to maintain separate working envelopes for each instrument and the camera.
Patient Positioning:
Patient positioning and table articulation can influence access and port placement in robotic procedures, especially in complex cases like thoracic surgery.
Complications
Early Complications:
Port site bleeding, injury to intra-abdominal organs (bowel, bladder, vessels), trocar herniation, gas embolism, wound infection.
Late Complications:
Port site metastasis (in oncologic surgery), chronic pain at port sites, incisional hernias.
Prevention Strategies:
Careful visualization of abdominal wall layers before trocar insertion, use of blunt-tip trocars or open technique for initial access, proper instrument handling, and adequate port spacing to avoid collisions.
Key Points
Exam Focus:
Understand the standard port placement for common laparoscopic procedures (cholecystectomy, appendectomy, TAPP, hysterectomy) and the underlying principles of triangulation and ergonomics
Be aware of robotic surgery port placement differences.
Clinical Pearls:
Always visualize the abdominal wall before inserting the primary trocar to avoid injury
Consider the specific anatomy and the planned dissection when placing secondary ports
Adapt placement based on patient body habitus and previous surgery
Never hesitate to add or reposition a port if visualization or manipulation is compromised.
Common Mistakes:
Placing ports too close together, leading to instrument collisions and restricted movement
Insufficient visualization of the abdominal wall during insertion
Failing to consider the operative table's position and surgeon's ergonomic needs
Not adapting port placement for obese or previously operated patients.