Distal Pancreatectomy

 

Executive Summary

Distal pancreatectomy, the surgical resection of the pancreatic body and tail, remains a critical intervention for localized chronic pancreatitis, malignancies, and cystic neoplasms. While diffuse chronic pancreatitis is increasingly managed through other means, anatomic distal pancreatectomy is indicated when disease is confined to the left side of the gland. This document outlines the two primary surgical approaches: the traditional open technique and the increasingly common laparoscopic approach.

Key takeaways include:

• Patient Selection: Success depends on identifying localized disease via CT, MRI, or EUS and addressing comorbid factors like narcotic or alcohol dependency.

• Procedural Precision: Critical steps involve the early identification of the superior mesenteric vein (SMV) and the careful management of the splenic vessels to prevent hemorrhage.

• Surgical Choice: Laparoscopy is favored for most distal resections but is contraindicated in cases of severe adhesions or resections requiring extended vascular involvement.

• Splenic Preservation: This remains a goal for benign disease to avoid the risk of postsplenectomy sepsis, though it is technically challenging in the presence of inflammation.

• Postoperative Care: Standardized protocols focusing on early mobilization, monitoring for pancreatic fistulas via drain amylase, and managing potential endocrine insufficiency (diabetes) are essential for recovery.

Indications and Contraindications

General Indications

Distal pancreatectomy is indicated for conditions predominantly confined to the body or tail of the pancreas, including:

• Chronic Pancreatitis: Specifically when pain is due to posttraumatic or postnecrotic strictures of the main pancreatic duct in the distal region.

• Malignancy: Adenocarcinoma arising from the tail of the pancreas or functioning/nonfunctioning neuroendocrine neoplasms.

• Complications: Pancreatic ascites resulting from ductal disruption or pseudocysts in the distal body/tail.

• Cystic Neoplasms: Symptomatic or suspicious cystic lesions.

Contraindications

The procedure may be contraindicated or yield variable results under the following conditions:

• Diffuse Disease: Changes throughout the entire gland (though predominance in the left gland may occasionally justify the procedure).

• Laparoscopic Constraints: Left-sided sinistral portal hypertension or extensive prior abdominal surgery with severe adhesions.

• Systemic Factors: Untreated autoimmune pancreatitis or genetic abnormalities involving the entire gland.

Preoperative Investigation and Preparation

Clinical and Laboratory Evaluation

A thorough history must be taken, focusing on trauma, alcohol abuse, steatorrhea, diabetes, and family history of pancreatic disease. For patients with active dependency, commitment to a controlled detoxification program is encouraged postoperatively.

• Labs: CBC, glucose, serum calcium, triglycerides, liver function tests, and albumin.

• Tumor Markers: CA 19-9, gastrin, chromogranin A, pancreatic polypeptide, and insulin (for suspected neuroendocrine tumors).

Imaging and Considerations

• Imaging Modalities: CT, MRI, or Endoscopic Ultrasound (EUS) are used to assess parenchymal disease and metastatic spread. ERCP is utilized to evaluate ductal and biliary strictures.

• Splenectomy Prophylaxis: If a splenectomy is anticipated, patients must be immunized with pneumococcal, Haemophilus influenzae type b, and meningococcal vaccines at least two weeks prior to surgery.

• Pain and DVT Management: Consider epidural catheters for postoperative pain (noting that narcotic dependence is a relative contraindication). DVT prophylaxis includes sequential compression devices and/or subcutaneous heparin.

Surgical Techniques: Open Distal Pancreatectomy

The classic "prograde" resection (left to right) involves the following steps:

Step	Description
1. Initial Exposure	Bilateral subcostal or midline incision; the lesser sac is entered by dissecting the greater omentum off the transverse colon.
2. SMV Identification	The middle colic vein is followed to localize the SMV. A tunnel is developed behind the pancreatic neck.
3. Spleen Mobilization	Lateral peritoneal attachments and the splenocolic ligament are divided. Short gastric vessels are ligated.
4. Pancreas Mobilization	The gland is elevated, staying between the kidney and the pancreatic tail to leave Gerota’s fascia undisturbed.
5. Splenic Artery Ligation	The artery is isolated near the celiac axis, suture-ligated or stapled, and divided.
6. Splenic Vein Ligation	The vein is ligated close to its junction with the SMV/portal vein. A Satinsky clamp may be used before oversewing the proximal end.
7. Gland Transection	The neck is divided over the SMV. The pancreatic duct is ligated with 3-0 polypropylene, and the cut edge is closed with a running suture or linear stapler.

Surgical Techniques: Laparoscopic Distal Pancreatectomy

This approach requires advanced skills, including two-handed dexterity and familiarity with laparoscopic energy devices.

1. Access: A 5-mm optical trocar is placed in the left upper quadrant, followed by four additional trocars (two 5-mm and two 10/12-mm).

2. Lesser Sac Entry: The gastrocolic omentum is divided with ultrasonic shears, sparing the gastroepiploic vessels.

3. SMV Tunneling: The junction of the right gastroepiploic vein and the SMV is identified to develop a space behind the pancreatic neck.

4. Lateral Mobilization: The dissection proceeds laterally along the inferior border. The inferior mesenteric vein (IMV) is typically divided between clips.

5. Neck Division: An Endo-GI stapler is used. A maximum staple height of 4.3 mm (typically using Seamguard) is recommended to avoid fracturing the gland.

6. Splenic Vessel Division: The splenic artery is divided first to avoid splenic congestion and bleeding from short gastric vessels.

7. Specimen Extraction: The pancreas is placed in a 10-mm endocatch bag, while the spleen is morcellated in a 15-mm bag.

Splenic Preservation Considerations

Preservation is justified for benign disease when the splenic vein is patent. However, inflammation often makes this "tedious and often impossible."

• Technique: The operation proceeds from right to left. The pancreatic neck is divided first, and the body/tail is dissected toward the spleen.

• Vascular Control: Numerous small branches from the splenic artery and vein entering the pancreas must be individually ligated or controlled with fine staples or silk ties.

• Medial Approach: In the presence of a posterior pseudocyst or severe inflammation, it is often more prudent to enter the retropancreatic space medially near the SMV rather than attempting lateral mobilization.

Postoperative Management and Complications

Recovery Protocol

• Day 1: Removal of Foley catheter and initiation of oral diet.

• Day 3: Checking of drain amylase. The drain is removed if no fistula is present.

• Day 3-4: Typical discharge window for uncomplicated cases.

Potential Complications

• Short-term: Intra-abdominal bleeding, pancreatic fistula, injury to the splenic flexure of the colon, and thrombocytosis.

• Long-term: Diabetes mellitus, pancreatic pseudocyst, disease recurrence, exocrine insufficiency, and the specific risk of postsplenectomy sepsis.

Expert Surgical Insights ("Tricks of the Senior Surgeon")

• Vascular Preparedness: Major intraoperative problems often stem from injuries to major veins due to excessive traction. An assortment of vascular clamps should always be ready on the back table.

• The "Handle" Concept: During open surgery, even if the spleen is injured, it can serve as a useful "handle" for the distal pancreas during the remainder of the dissection.

• Anatomic Identification: In laparoscopic procedures, the surgeon must avoid mistaking the hepatic artery for the splenic artery. This is managed by dividing the neck first to expose the origin of the splenic artery and test-clamping to visualize flow.

• Gravity and Exposure: In laparoscopy, completely mobilizing the splenic flexure of the colon and using reverse Trendelenburg positioning optimizes exposure of the pancreatic tail and splenic hilum.