Principles of hepatic, pancreatic and biliary surgery: resection, reconstruction, palliation

Definition / Overview

Hepatic, pancreatic, and biliary (HPB) surgery encompasses some of the most technically demanding procedures in general surgery. Mastery of the underlying anatomical relationships, oncological staging principles, reconstructive options, and palliation strategies is essential for the FRACS candidate. This note addresses the key principles that underpin decision-making in HPB surgery from a consultant-surgeon perspective.

Anatomy and Surgical Exposure

Hepatic Anatomy

• The liver is divided into 8 functional segments (Couinaud), each with an independent portal pedicle and hepatic venous drainage, the foundation of anatomical resection.
• The Brisbane 2000 terminology standardises nomenclature: right/left hemiliver separated by the middle hepatic vein (Cantlie's line); further subdivided into sections and segments.
• The hepatoduodenal ligament (portal triad: portal vein, hepatic artery, common bile duct) forms the free edge of the lesser omentum and is the site of the Pringle manoeuvre (inflow occlusion).
• The caudate lobe (segment I) has direct hepatic venous drainage to the IVC and receives dual portal and arterial supply, relevant in hilar cholangiocarcinoma resection.

Pancreatic Anatomy

• The pancreas lies retroperitoneally; the head is intimately related to the duodenum, common bile duct (intrapancreatic portion), and the superior mesenteric vessels.
• The uncinate process wraps behind the superior mesenteric vein (SMV) and artery (SMA), a critical plane in pancreaticoduodenectomy.
• The main pancreatic duct (of Wirsung) joins the common bile duct at the ampulla of Vater; an accessory duct (of Santorini) may drain to the minor papilla.
• Arterial supply: head via gastroduodenal artery (GDA) and inferior pancreaticoduodenal artery; body/tail via splenic artery branches.

Biliary Anatomy

• The common hepatic duct is formed by union of right and left hepatic ducts; it becomes the common bile duct (CBD) after the cystic duct joins.
• Anatomical variants are common: right posterior sectoral duct draining into the left hepatic duct or directly into the cystic duct occurs in up to 20% of patients, injury risks are highest at cholecystectomy.
• The critical view of safety must be established in every cholecystectomy to avoid inadvertent CBD injury.

Pathophysiology and Oncological Staging

Hepatocellular Carcinoma (HCC)

• Develops predominantly on a background of cirrhosis; Barcelona Clinic Liver Cancer (BCLC) staging guides therapy.
• Child-Pugh and MELD scores assess hepatic reserve; the future liver remnant (FLR) must be adequate (≥20% of total liver volume in a normal liver; ≥40% in a cirrhotic liver).
• Portal hypertension is a relative contraindication to resection.

Cholangiocarcinoma

• Hilar (Klatskin) tumours classified by Bismuth-Corlette (Types I-IV) based on ductal involvement.
• Distal cholangiocarcinoma staged by AJCC TNM (8th edition) using depth of invasion, lymph node number, and metastases; at least 12 lymph nodes should be harvested.
• Resectability criteria for hilar disease: absence of bilateral secondary biliary radical involvement, absence of bilateral vascular involvement, absence of distant metastases, and adequate FLR.

Pancreatic Ductal Adenocarcinoma (PDAC)

• Staged by AJCC TNM; operationally classified as resectable, borderline resectable, locally advanced (unresectable), or metastatic.
• Approximately 80% of patients are not candidates for curative resection at diagnosis; 30% present with non-metastatic locally advanced disease.
• Resectability hinges on relationship to SMV/portal vein, SMA, hepatic artery, and celiac axis; involvement of the SMV/portal vein with $\leq 180°$ abutment may still be resectable with vascular reconstruction.

Operative Principles: Resection

Hepatic Resection

Key operative principles:

• Pringle manoeuvre (up to 60 minutes intermittent) controls inflow haemorrhage during parenchymal transection.
• Parenchymal transection methods: CUSA, bipolar diathermy, LigaSure, water-jet dissection, or stapler-based techniques, choice based on surgeon preference and tissue characteristics.
• Hepatic vein control before or after parenchymal transection; the IVC may require isolation for tumours with caval involvement.
• Portal vein embolisation (PVE) of the tumour-bearing lobe 4-6 weeks preoperatively increases FLR volume when FLR is marginal.
• Two-stage hepatectomy and ALPPS (Associating Liver Partition and Portal vein ligation for Staged hepatectomy) are strategies for patients requiring extensive resection with insufficient FLR.

Pancreatic Resection

Pancreaticoduodenectomy (Whipple Procedure):

1. Assess resectability, explore for hepatic/peritoneal metastases before committing.
2. Kocherise the duodenum; assess the SMA/SMV plane (the "mesenteric triangle" is the critical margin).
3. Divide: common hepatic duct, gastric antrum or duodenum (pylorus-preserving variant), jejunum 10-15 cm distal to Treitz, and neck of pancreas over the SMV.
4. Dissect the uncinate process off the SMA, this defines the retroperitoneal (R1) margin, the most frequent site of positive margins.
5. Reconstruction: pancreatojejunostomy or pancreatogastrostomy, hepaticojejunostomy, and gastrojejunostomy (or duodenojejunostomy) in Roux-en-Y fashion.
6. Venous reconstruction (segmental resection with primary repair, patch, or interposition graft) is performed when SMV/portal vein involvement prevents margin-free dissection.

Distal Pancreatectomy:

• Standard resection for body/tail lesions; splenectomy is performed for malignancy.
• Splenic vessel dissection from the pancreatic parenchyma allows spleen-preserving distal pancreatectomy for benign or borderline lesions.
• Laparoscopic distal pancreatectomy is the preferred approach for suitable lesions, equivalent oncological outcomes with shorter hospital stay.

Total Pancreatectomy:

• Reserved for multi-focal disease, IPMN with diffuse involvement, or positive neck margin intraoperatively.
• Results in brittle diabetes and exocrine insufficiency, demanding long-term management.

Biliary Resection

• Cholecystectomy: laparoscopic is standard; conversion criteria include failure to achieve critical view, bleeding, or suspicion of injury.
• Bile duct excision for distal cholangiocarcinoma is performed as part of a Whipple procedure (pancreaticoduodenectomy).
• Hilar resection for Klatskin tumours requires en-bloc hepatectomy (typically right or left with caudate lobectomy) to achieve R0 margins; isolated bile duct excision is rarely adequate.
• Preoperative biliary drainage via ERCP or PTC is indicated when FLR bilirubin function is impaired, especially before major hepatectomy; routine stenting for distal cholangiocarcinoma is discouraged due to infectious risk.

Operative Principles: Reconstruction

Biliary Reconstruction

• Roux-en-Y hepaticojejunostomy is the gold standard for biliary-enteric anastomosis, used after bile duct injury, biliary resection, and palliation of obstruction.
• A 60 cm Roux limb is standard; the bowel is brought through the transverse mesocolon (retrocolic) or anterior to it (antecolic) depending on anatomy.
• End-to-side configuration is used for hepaticojejunostomy; the anastomosis is fashioned before the jejunojejunostomy to reduce tension.
• Anastomotic stents (transanastomotic or T-tube) may be used when the duct is small ($< 5\,\text{mm}$) or the anastomosis is under any tension.
• For cholecystojejunostomy (palliative): simpler than hepaticojejunostomy, but requires a patent cystic duct and is inappropriate when tumour may obstruct the cystic duct-CBD junction.

Pancreatic Reconstruction

• Pancreatojejunostomy (duct-to-mucosa or invagination technique) vs. pancreatogastrostomy, no definitive evidence of superiority of one approach; surgeon familiarity and pancreatic texture/duct size inform choice.
• A soft pancreas with a small duct carries the highest risk of post-operative pancreatic fistula (POPF); external stenting of the main pancreatic duct may reduce POPF rate in high-risk glands.
• Octreotide prophylaxis remains debated, some evidence of benefit in soft pancreas/small duct settings.

Palliation

Biliary Palliation

• Metal self-expanding stents (SEMS) are preferred over plastic stents for patients with life expectancy $> 3$ months, longer patency.
• For hilar cholangiocarcinoma, bilateral stenting (right and left systems) achieves better palliation but is technically demanding.

Gastric Outlet Obstruction Palliation

• Approximately 3-20% of unresectable pancreatic head cancer patients will develop gastric outlet obstruction.
• Antecolic loop gastrojejunostomy is the standard surgical approach, allows the patient to eat with minimal morbidity.
• Endoscopic duodenal stenting is an alternative for patients with very limited life expectancy or high operative risk.
• Prophylactic gastrojejunostomy at the time of biliary bypass remains controversial; surgeons must weigh operative morbidity against the risk of future obstruction.

Pain Palliation: Chemical Splanchnicectomy

• Performed at open exploration when unresectability is confirmed.
• Technique: 20 mL of 50% ethanol injected on each side of the aorta at the level of the celiac plexus using a spinal needle, destroys the celiac ganglion afferent fibres.
• Evidence from prospective randomised trials supports improved pain control and reduced opioid requirements; survival benefit is not established.
• EUS-guided celiac plexus neurolysis is the equivalent non-operative approach.

Complications and Special Considerations

Post-Hepatectomy Liver Failure (PHLF)

• Defined by the International Study Group of Liver Surgery (ISGLS) criteria: elevated bilirubin and/or INR on day 5 post-operatively not explained by other causes.
• Risk factors: small FLR, cirrhosis, steatosis, preoperative chemotherapy-induced injury (sinusoidal obstruction syndrome after oxaliplatin).
• Management: supportive (enteral nutrition, avoid nephrotoxins, treat infection), consider MARS or liver support systems in severe cases.

Post-Operative Pancreatic Fistula (POPF)

• Classified Grade A (biochemical leak), B (clinical impact, drain management change), C (re-operation or organ failure).
• Grade B/C POPF: drain amylase $> 3\times$ upper limit of normal on or after day 3 with clinical sequelae.
• Management: keep drains in situ, CT to assess for collection, IR-guided drainage of undrained collections, nutritional support; re-operation for haemorrhage from a sentinel bleed (pseudoaneurysm formation, typically from the GDA stump or hepatic artery).

Post-Operative Haemorrhage

• Early ($< 24$ h): surgical bleeding, return to theatre.
• Late ($> 5$ days): sentinel bleed from pseudoaneurysm in context of POPF, CT angiography and interventional radiology embolisation are first-line; surgical ligation if IR fails.

Anastomotic Leak (Hepaticojejunostomy)

• Presents with bile in drains, fever, rising bilirubin.
• Management: ensure adequate drainage, ERCP/PTC if drain inadequate, re-operation for peritonitis.

Bile Duct Injury (Cholecystectomy)

• Immediate recognition at operation: repair over T-tube (simple transection) or Roux-en-Y hepaticojejunostomy.
• Delayed recognition: control sepsis, percutaneous drainage of biloma, PTC for cholangiography and external drainage, definitive repair deferred 6-8 weeks until inflammation resolves; Roux-en-Y hepaticojejunostomy is the standard definitive repair.

Perioperative and MDT Management

Neoadjuvant and Adjuvant Therapy in HPB Oncology

• MDT decisions should include HPB surgeon, oncologist, radiologist, pathologist, and gastroenterologist/hepatologist.
• Staging laparoscopy is recommended before planned Whipple procedure for PDAC to exclude occult peritoneal or hepatic disease ($\sim 10\%$ upstaged), avoiding non-therapeutic laparotomy.

Perioperative Essentials

• DVT prophylaxis: LMWH commenced within 12-24 hours post-operatively (once haemostasis confirmed), combined with pneumatic compression devices intraoperatively and post-operatively; extended prophylaxis (28 days) for major oncological HPB resections.
• Enhanced Recovery After Surgery (ERAS): multimodal analgesia (epidural or TAP blocks), early enteral feeding, restricted IV fluids, early mobilisation, reduces hospital stay and complication rates after hepatectomy and pancreatectomy.
• Nutritional optimisation: Pre-operative nutritional assessment; enteral supplementation for malnourished patients; post-Whipple patients require pancreatic enzyme replacement therapy (PERT), typically pancrelipase (Creon) 25,000-50,000 lipase units with each meal.
• Glycaemic control: Target blood glucose $4-10\,\text{mmol/L}$ in the perioperative period; insulin infusion for patients with pancreatic resection and new-onset or worsening diabetes.

Key Viva Points

• R0 resection is the only chance of cure in HPB malignancy, intraoperative frozen sections of bile duct margins are mandatory in cholangiocarcinoma resection.
• The retroperitoneal (SMA) margin is the critical margin in pancreaticoduodenectomy and the most common site of R1 disease.
• Operative palliation is preferred over endoscopic stenting in patients found unresectable at laparotomy with a reasonable performance status and life expectancy, hepaticojejunostomy is more durable.
• Chemical splanchnicectomy at time of open exploration for unresectable PDAC provides superior pain control and should be routinely offered.
• A soft, small-duct pancreas after Whipple carries the highest POPF risk; recognise the sentinel bleed from pseudoaneurysm as a life-threatening complication requiring urgent IR angiography.
• Adequate FLR volume and function are the prerequisites for safe major hepatectomy, PVE is a key strategy when FLR is marginal.

Sources

• RACS position statements & curriculum (Royal Australasian College of Surgeons)
• ANZGOSA (Australia & NZ Gastric & Oesophageal Surgery Association)