Overview
Definition:
Anatomical hepatic segmentectomy of segment 6 involves the surgical removal of liver segment VI, respecting its distinct vascular pedicles and biliary drainage, based on the Couinaud segmental anatomy
This precise resection aims to achieve oncologic clearance or manage benign lesions while preserving maximum functional liver parenchyma.
Epidemiology:
The incidence of primary liver tumors amenable to segmentectomy is increasing
Segment VI is the most posterior segment, making it prone to specific pathologies like metastatic disease or hepatocellular carcinoma arising in the posterior liver
Precise anatomical knowledge is crucial for all liver resections.
Clinical Significance:
Accurate anatomical segmentectomy of segment VI is vital for achieving negative margins in oncologic resections, minimizing blood loss by controlled vascular inflow and outflow, and reducing postoperative liver failure
It is a cornerstone of modern hepatobiliary surgery for managing localized liver disease and optimizing patient outcomes.
Indications
Tumor Resection:
Resection of primary or metastatic tumors located exclusively within segment VI with clear margins
Commonly indicated for hepatocellular carcinoma (HCC), colorectal liver metastases, and neuroendocrine tumors.
Benign Lesions:
Treatment of symptomatic benign liver lesions such as adenomas, hemangiomas, or focal nodular hyperplasia that are causing pain or are at risk of rupture, located in segment VI.
Inflammatory Conditions:
Management of focal abscesses or cysts within segment VI unresponsive to conservative management, where a segmentectomy offers definitive treatment.
Preoperative Assessment:
Thorough evaluation of liver function (Child-Pugh score, MELD score), tumor staging, and assessment of vascular involvement
Importance of cross-sectional imaging (CT, MRI) for precise anatomical mapping.
Preoperative Preparation
Patient Evaluation:
Comprehensive assessment of patient comorbidities, nutritional status, and pulmonary function
Risk stratification for major abdominal surgery.
Imaging Studies:
Contrast-enhanced CT and/or MRI with 3D reconstructions are essential for defining tumor location, vascular anatomy (portal veins, hepatic veins), and biliary tree anatomy relevant to segment VI
Angiography may be used for complex vascular cases.
Anesthesia Considerations:
General anesthesia with endotracheal intubation and controlled ventilation
Considerations for fluid management, blood transfusion availability, and intraoperative monitoring (e.g., central venous pressure, arterial line).
Surgeon Planning:
Detailed preoperative planning by the surgeon, including visualization of the surgical field, identification of key vascular and biliary structures, and strategy for parenchymal transection
Familiarity with Pringle maneuver or intermittent pedicle clamping.
Procedure Steps
Approach:
Laparoscopic or open approach, typically through a subcostal or midline laparotomy
Robotic-assisted surgery is also an option for enhanced visualization and precision.
Parenchymal Dissection:
Identification of the Glissonean pedicle supplying segment VI and the corresponding venous outflow into the hepatic vein
Using instruments like CUSA, harmonic scalpel, or monopolar cautery for controlled parenchymal transection along the defined intersegmental plane.
Vascular Control:
Dissection and ligation of the Glissonean pedicle for segment VI
Identification and preservation or division of the relevant hepatic vein draining segment VI
Emphasis on meticulous hemostasis and bile duct control.
Biliary Management:
Careful identification and sealing or ligation of any small biliary radicals originating from segment VI
Intraoperative cholangiography may be performed if biliary anatomy is unclear or significant biliary structures are involved.
Postoperative Care
Monitoring:
Close monitoring of vital signs, urine output, and abdominal drain output
Serial assessment for signs of bleeding, bile leak, or hepatic insufficiency.
Pain Management:
Adequate analgesia, typically using patient-controlled analgesia (PCA) or epidural anesthesia, to ensure patient comfort and facilitate early mobilization.
Nutritional Support:
Early enteral feeding is encouraged
Nutritional assessment and supplementation may be required for patients with impaired nutritional status or significant liver resection.
Complication Surveillance:
Vigilant surveillance for postoperative complications such as intra-abdominal collections (hematoma, biloma), pneumonia, venous thromboembolism, and hepatic decompensation
Regular laboratory monitoring of liver function tests and coagulation profile.
Complications
Early Complications:
Hemorrhage from transected vessels or cut surfaces
Bile leak (biloma formation, biliary peritonitis)
Post-hepatectomy liver failure (PHLF), manifesting as jaundice, ascites, and coagulopathy
Wound infection and intra-abdominal abscess.
Late Complications:
Biliary strictures or cholangitis
Adhesions and bowel obstruction
Incisional hernia
Long-term hepatic dysfunction in cases of extensive resection or underlying liver disease.
Prevention Strategies:
Meticulous surgical technique with precise vascular and biliary control
Use of intraoperative imaging and intraoperative ultrasound
Adequate hemostasis
Judicious use of Pringle maneuver
Prophylactic antibiotics
Early mobilization and respiratory physiotherapy.
Prognosis
Factors Affecting Prognosis:
Type and stage of the underlying liver disease (e.g., benign vs
malignant)
Extent of liver resection
Pre-existing liver function
Presence of complications
Surgical expertise and facility resources.
Outcomes:
For benign lesions, prognosis is excellent with complete resolution of symptoms and no long-term sequelae
For malignant tumors, prognosis depends on oncologic factors, including tumor grade, stage, and margin status
Survival rates vary significantly based on histology.
Follow Up:
Regular follow-up with clinical examination and imaging (CT/MRI) is crucial, especially for patients with malignant disease, to monitor for recurrence
Frequency of follow-up depends on the underlying pathology and oncologic guidelines.
Key Points
Exam Focus:
Understanding of hepatic segmental anatomy (Couinaud classification) is paramount
Differentiating anatomical vs
non-anatomical resection
Identifying key vascular and biliary structures of segment VI
Recognizing potential complications and their management.
Clinical Pearls:
Always confirm segment VI location with pre-operative imaging
Trace the Glissonean pedicle and draining hepatic vein meticulously
Use intraoperative ultrasound to confirm segmental boundaries and vascular structures
Be prepared for potential bleeding or bile leak.
Common Mistakes:
Inadequate margin in oncologic resections
Uncontrolled bleeding due to insufficient vascular control
Inadvertent injury to adjacent segments or major vessels/bile ducts
Failure to recognize and manage postoperative liver failure or bile leaks promptly.