Overview
Definition:
Right posterior sectionectomy is a surgical procedure involving the removal of hepatic segments 6 and 7 of the liver
These segments constitute the right posterior sector of the liver, situated inferiorly and posteriorly on the right lobe
This resection is typically performed for localized hepatic malignancies or benign lesions within these specific segments.
Epidemiology:
The incidence of indications for right posterior sectionectomy is tied to the prevalence of liver tumors
Hepatocellular carcinoma (HCC) and colorectal liver metastases are common indications
The occurrence varies geographically and is influenced by risk factors for primary liver cancers
Benign lesions requiring resection are less common but may include large hemangiomas or adenomas.
Clinical Significance:
This procedure is critical for achieving complete oncologic resection of tumors confined to segments 6 and 7, offering the potential for cure or prolonged survival
Precise execution is paramount to minimize operative morbidity and preserve adequate future liver remnant (FLR)
Understanding the segmental anatomy and vascular supply is vital for safe and effective resection.
Indications
Oncologic Indications:
Primary liver tumors (e.g., hepatocellular carcinoma, cholangiocarcinoma) limited to segments 6 and 7
Isolated metastases from other primaries (e.g., colorectal, neuroendocrine tumors) located within these segments
Circumscribed benign tumors (e.g., large hemangioma, hepatocellular adenoma) causing symptoms or posing a risk of rupture/malignancy transformation.
Non Oncologic Indications:
Segmental hepatic dysfunction or trauma requiring isolation and removal of the affected sector
Certain parasitic infections or inflammatory conditions localized to the posterior sector
Recurrent disease in segments 6-7 after prior treatment where wider resection is not feasible.
Selection Criteria:
Tumor or lesion confined to segments 6 and 7 with no involvement of major vascular structures (hepatic veins, portal vein)
Adequate FLR to sustain postoperative liver function (typically >30% in standard resections, higher in cirrhotic livers)
Absence of extrahepatic disease or extensive intrahepatic spread
Patient must be medically fit for major surgery.
Preoperative Preparation
Patient Assessment:
Thorough medical evaluation including cardiopulmonary assessment
Detailed nutritional status assessment
Assessment of liver function using Child-Pugh score and MELD score, especially in patients with underlying liver disease.
Imaging Studies:
Contrast-enhanced computed tomography (CT) scan for detailed tumor mapping, vascular anatomy, and FLR estimation
Magnetic resonance imaging (MRI) for better soft tissue characterization and detection of small lesions
Doppler ultrasound to assess portal vein patency and hepatic venous flow.
Surgical Planning:
Multidisciplinary team discussion (hepatologist, radiologist, oncologist, surgeon)
Preoperative embolization of feeding vessels if necessary for large tumors
Consultation with anesthesiology regarding fluid management and hemodynamic monitoring
Planning for potential intraoperative blood transfusion.
Procedure Steps
Approach And Exposure:
Transabdominal approach, typically through a right subcostal or Mercedes incision
Adequate exposure of the liver and porta hepatis
Mobilization of the right liver lobe and gallbladder
Identification of the relevant hepatic pedicles and vessels.
Vascular Control:
Identification and control of the right hepatic artery, right portal vein branches supplying segments 6 and 7
Ligation of the corresponding hepatic venous drainage into the inferior vena cava (IVC)
Careful dissection to avoid injury to major vessels or remaining liver parenchyma.
Parenchymal Dissection:
Dividing the liver parenchyma along the defined resection plane using techniques like ultrasonic dissector, harmonic scalpel, or Pringle maneuver if necessary
Careful hemostasis and bile duct ligation
Anatomical landmarks, including the hepatic veins and portal vein bifurcation, guide the resection plane.
Closure And Drainage:
Inspection for bleeding and bile leaks
Placement of drainage catheters in the resection bed
Layered closure of the abdominal incision
Use of fibrin glue or hemostatic agents as needed.
Postoperative Care
Monitoring:
Close monitoring of vital signs, urine output, and fluid balance
Frequent assessment for signs of bleeding (hemorrhage) or bile leak (choleperitoneum)
Monitoring of liver function tests (LFTs), coagulation profile, and electrolytes.
Pain Management:
Adequate analgesia, often using patient-controlled analgesia (PCA) or epidural analgesia
Early ambulation to prevent pulmonary complications and deep vein thrombosis (DVT).
Nutritional Support:
Initiation of oral feeding as tolerated, often starting with clear liquids
If ileus or significant nausea/vomiting, parenteral nutrition may be required
Monitoring for signs of hepatic decompensation.
Complication Surveillance:
Vigilant monitoring for signs of post-hepatectomy liver failure (PHLF), sepsis, wound infection, pleural effusion, and ascites
Prophylaxis against DVT and stress ulceration.
Complications
Early Complications:
Hemorrhage from the resection surface or injured vessels
Bile leak from the cut surface or ligated ducts (biloma, biliary peritonitis)
Postoperative hepatic failure (PHLF) leading to encephalopathy, coagulopathy, and jaundice
Sepsis originating from intra-abdominal infection or cholangitis.
Late Complications:
Biliary strictures or leaks developing days to weeks postoperatively
Incisional hernia
Adhesions and bowel obstruction
Recurrence of malignancy
Chronic liver dysfunction in patients with pre-existing liver disease.
Prevention Strategies:
Meticulous surgical technique with precise vascular control and hemostasis
Accurate identification and ligation of bile ducts
Adequate FLR calculation and optimization
Prophylactic antibiotics
Early mobilization and chest physiotherapy
Careful fluid management and electrolyte balance.
Prognosis
Factors Affecting Prognosis:
Stage of the malignancy
Underlying liver function (presence and severity of cirrhosis)
Extent of resection and margin status (R0 resection is crucial)
Development of postoperative complications
Patient's overall health status.
Outcomes:
For oncologic indications, a successful R0 resection offers the best chance for long-term survival
Prognosis is generally favorable for benign lesions
The risk of complications is significant, with PHLF being the most serious
Survival rates for HCC vary widely based on tumor stage and liver function.
Follow Up:
Regular follow-up with imaging (CT/MRI) every 3-6 months for oncologic surveillance
Monitoring of liver function tests and general well-being
Long-term follow-up for potential recurrence or development of new primary tumors, especially in patients with chronic liver disease.
Key Points
Exam Focus:
Understanding the anatomical boundaries of segments 6 and 7
Key vascular supply and drainage (right portal vein branches, right hepatic vein tributaries)
Indications for resection and contraindications
Management of postoperative complications, particularly PHLF and bile leaks.
Clinical Pearls:
Preoperative imaging is paramount for precise surgical planning and risk stratification
Achieving negative resection margins (R0) is the goal for oncologic resections
Preserving adequate FLR is critical to avoid postoperative liver failure
Liberal use of intraoperative ultrasound can aid in anatomical orientation.
Common Mistakes:
Inadequate visualization of vascular structures leading to bleeding or accidental resection of non-target segments
Failure to achieve R0 resection margin
Insufficient FLR leading to liver failure
Underestimation of the severity of underlying liver disease
Delayed recognition and management of postoperative complications.