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Surgical Techniques
Mesopancreas Triangle Definition

The mesopancreas triangle is a retropancreatic anatomical region critical in pancreatic head cancer surgery. It is defined as a triangular area with the following boundaries:

  • Base: Posterior surface of the superior mesenteric vein (SMV) and portal vein (PV).
  • Apex: Anterior surface of the aorta, between the origins of the celiac axis (CA) and superior mesenteric artery (SMA).
  • Lateral boundaries: Right semi-circumferences of the CA and SMA plexuses.
  • This region contains loose areolar tissue, adipose tissue, nerve plexuses, lymphatics, and capillaries, but lacks a distinct fascial envelope, unlike the mesorectum. It is a primary site for cancer infiltration and local recurrence after pancreaticoduodenectomy (PD) due to its proximity to critical vascular structures and lymph nodes.
 
 First Description of the Mesopancreas Triangle

The term “mesopancreas” was introduced in 2007 by Gockel et al., drawing an analogy to the mesorectum, to describe the retropancreatic perineural and lymphatic tissue dorsal to the pancreas. The specific concept of the mesopancreas triangle was later refined by Adham and Singhirunnusorn in 2012, who provided a detailed anatomical description, characterizing it as an inverted triangle with the boundaries noted above. Their work emphasized its surgical relevance in pancreatic head carcinoma resection, particularly for achieving negative resection margins (R0 resection).

Total Mesopancreas Excision (TMpE)

Purpose: TMpE aims to completely remove the mesopancreas, including its neurovascular and lymphatic tissues, during pancreaticoduodenectomy to achieve R0 resection (no residual tumor). The mesopancreas is a common site for R1 resection (microscopic residual tumor), which is associated with higher local recurrence rates (up to 80% within the first postoperative year).

  • Clinical Impact: Studies have shown TMpE increases R0 resection rates (e.g., 80.7–94.8% vs. 60–81.4% in conventional PD), reduces local recurrence (e.g., 7.8% vs. 23.7% at six months), and extends disease-free survival (e.g., 16.9 vs. 13.4 months). It involves meticulous dissection along the SMA and CA, often using an artery-first approach to control vascular inflow and ensure clearance of the mesopancreatic root.
  • Techniques: TMpE can be performed as a standard (Level I) or extended (Level II) procedure, with Level II involving additional dissection (e.g., full-circle SMA clearance or para-aortic lymph node dissection) for borderline resectable tumors. It may include vascular resection (e.g., SMV/PV) when tumor invasion is present.
  • Safety and Feasibility: TMpE is considered safe in experienced hands, with no significant increase in operative time, blood loss, or complications compared to standard PD. Postoperative complications occur in approximately 39.7–45% of cases, with no perioperative mortality reported in some series.
 

Triangle Operation

Definition: The triangle operation, often associated with TMpE, involves en bloc resection of the mesopancreas within the triangular space defined by the SMA, CA, and PV/SMV, with complete skeletonization of these arteries. It is particularly used for borderline resectable pancreatic cancer (BRPC) or locally advanced pancreatic cancer (LAPC) after neoadjuvant therapy.

  • Relevance: This technique enhances radical clearance of retropancreatic tissues, reducing R1 resection rates in high-risk patients. It is feasible laparoscopically or robotically, with studies reporting no postoperative mortality and manageable complications (e.g., chyle leak, transient diarrhea). The operation is critical for tumors invading the mesopancreas or adjacent vessels, improving local control and potentially survival.
  • Challenges: The procedure requires advanced surgical expertise due to the complex anatomy and proximity to major vessels. It may involve vascular resection and reconstruction, increasing the risk of complications like lymphatic leak, though techniques like total pancreatectomy can mitigate risks such as pancreatic fistula.
 

Controversies and Considerations

The term “mesopancreas” is debated, as it lacks a true fascial boundary, leading some to propose alternative names like “pancreatic head plexus” or “pancreas-major arteries ligament.” However, the term remains widely used for its surgical utility.

  • TMpE and the triangle operation are not universally standardized, with variations in resection extent (e.g., en bloc vs. staged resection) and indications (resectable vs. borderline resectable tumors).
  • While TMpE improves R0 rates, its impact on overall survival remains less clear, with some studies showing no significant difference compared to conventional PD. Further large-scale, multicenter studies are needed to confirm long-term benefits.

📨🏠📝

  • Internal stent 🆚 No stent
    • No difference in POPF (2 studies)
  • External stent 🆚 No stent
    • External drainage reduces POPF (3 studies) & overall morbidity (1 study) 
    • No difference in POPF (1 study)
  • Internal 🆚 External
    • No difference in POPF (1 study)

Meta-analyisis / Systematic review

  • Stenting 🆚 No tenting 
    • No difference (1 study)
    • External stent may be beneficial to reduce POPF (4 studies) & overall morbidity (1 study) & LoS (1 study)
  • Internal stent
    • Not useful & may increase the risk of POPF in soft pancreas (1 study)
  • Internal 🆚 external
    • No difference (1 study)
Pancreatic duct stenting after pancreaticoduodenectomy (Whipple procedure) is a technique used to reduce complications, particularly pancreatic fistula, which is a significant cause of morbidity. Here’s a concise overview based on available evidence:
Purpose
  • Prevent Pancreatic Fistula: Stenting aims to divert pancreatic juice away from the pancreaticojejunal anastomosis, reducing the risk of leakage and fistula formation.
  • Support Anastomotic Healing: Facilitates healing by reducing pressure at the anastomosis site.
Types of Stents
  1. Internal Stents: Placed within the pancreatic duct and connected to the jejunum, allowing pancreatic juice to drain into the digestive tract.
  2. External Stents: Drained externally through a tube, often to a collection bag, allowing monitoring of pancreatic juice output.
Evidence and Outcomes
  • Reduction in Fistula Rates: Studies suggest stenting, particularly external stents, may reduce clinically significant postoperative pancreatic fistula (POPF) rates, especially in high-risk patients (e.g., soft pancreas, small duct size <3 mm). A 2018 meta-analysis found external stenting reduced POPF by 30-40% in such cases.
  • Internal vs. External: External stents may lower fistula rates more effectively but require removal and can cause discomfort. Internal stents avoid external tubes but may migrate or obstruct.
  • Complications: Stent-related issues include occlusion, migration, or infection. External stents may also cause prolonged hospital stays for management.
  • No Consensus: Some trials show no significant benefit, and routine stenting remains controversial. The decision often depends on surgeon preference and patient risk factors.
Considerations
  • Patient Selection: Stenting is more beneficial in high-risk cases (soft pancreas, small duct, high pancreatic juice output).
  • Technique: Placement requires precision to avoid duct injury. Stent size and material vary, with no universal standard.
  • Postoperative Management: External stents typically require monitoring and removal after 4-6 weeks, guided by imaging or amylase levels.
Current Practice
  • Guidelines (e.g., International Study Group on Pancreatic Surgery) suggest selective stenting in high-risk patients rather than routine use.
  • Ongoing research aims to standardize indications and techniques.

📨🏠📝

  • POPF
    • No difference (4 studies) ; Grade B/C no difference (1 study)
    • Favour PG (4 studies)
  • Severity of complication 
    • No difference (2 studies)

  • 👍 PG

    • ↘️ Biliary fistula (2 studies) ↘️ DGE (1 study)
      ↘️ Multiple surgical complications (1 study) ↘️ LoS (1 study)
      ↘️ Gastric reflux, pain & abdominal discomfort (1 study)
      ↘️ Intraabdominal fluide collection (1 study); No difference (2 studies)

  • 👎 PG
    • ↗️ Postoperative bleeding (1 study)
    • ↗️ Calvien-Dindo Grade ≥ 3 morbidity (1 study)
  • Global QoL
    • Equal (1 study)
  • Meta-analysis 
    • Provide equal results (1 meta-analysis)
    • PG ↘️ POPF based on ISGPF criteria (1 meta-analysis)

Pancreatico-gastrostomy (PG) and pancreatico-jejunostomy (PJ) are two surgical techniques used to reconstruct the pancreatic remnant after pancreaticoduodenectomy (Whipple procedure), a surgery for pancreatic head tumors or other periampullary diseases. The choice between PG and PJ remains debated, as each has potential advantages and drawbacks, primarily centered around postoperative complications like pancreatic fistula (POPF), delayed gastric emptying (DGE), and overall morbidity.

 Key Differences

  • Pancreatico-Gastrostomy (PG):
    • The pancreatic stump is anastomosed to the stomach.
    • Advantages:
      • The acidic gastric environment may reduce pancreatic enzyme activation, potentially lowering POPF risk.
      • The stomach’s thick wall and rich blood supply may promote better healing.
      • Easier endoscopic access for postoperative evaluation or intervention.
      • May reduce DGE due to preserved gastric motility in some configurations.
    • Disadvantages:
      • Potential for increased bleeding due to the stomach’s vascularity.
      • Risk of gastritis or ulceration from pancreatic secretions.
      • Less physiological, as pancreatic enzymes mix with gastric contents rather than intestinal contents.
  • Pancreatico-Jejunostomy (PJ):
    • The pancreatic stump is anastomosed to a loop of jejunum (small intestine).
    • Advantages:
      • More physiological, as pancreatic secretions enter the intestine, mimicking natural digestion.
      • Long-established technique with extensive surgeon experience.
      • Potentially lower risk of gastric complications (e.g., gastritis or bleeding).
    • Disadvantages:
      • Higher risk of POPF, especially in soft pancreatic texture or small pancreatic ducts.
      • Thinner jejunal wall may be less forgiving for anastomosis.
      • May contribute to DGE due to intestinal manipulation.

Clinical Evidence

  •  Postoperative Pancreatic Fistula (POPF):
    • Studies are mixed. Some randomized controlled trials (RCTs) and meta-analyses suggest PG reduces POPF rates (e.g., a 2016 meta-analysis showed lower POPF with PG, OR 0.66, p=0.002). Others, like the 2017 RECOPANC trial, found no significant difference in clinically relevant POPF (20% for PG vs. 22% for PJ, p=0.71).
    • POPF risk depends on pancreatic texture, duct size, and surgical technique (e.g., duct-to-mucosa vs. invagination).
  • Delayed Gastric Emptying (DGE):
    • PG may reduce DGE in some studies due to less disruption of gastric motility (e.g., a 2014 study reported DGE in 8% of PG vs. 17% of PJ, p=0.03). However, results vary, and DGE is multifactorial.
  • Morbidity and Mortality:
    • Overall morbidity rates are similar between PG and PJ in most RCTs. A 2020 meta-analysis found no significant difference in overall complications (OR 0.89, p=0.34) or mortality (OR 1.02, p=0.90).
    • PG may have a slight edge in reducing severe complications in high-risk patients (soft pancreas, small duct).
  • Long-Term Outcomes:
    • Both techniques show comparable long-term pancreatic exocrine and endocrine function. PG may have a slight risk of steatorrhea due to altered enzyme activation in the stomach, but data is inconclusive.

 Current Practice

  • Surgeon Preference and Expertise: The choice often depends on surgeon experience and institutional protocols. PJ is more common due to its historical use and familiarity.
  • Patient Factors: PG may be preferred in high-risk cases (e.g., soft pancreas, small duct <3 mm) due to potential lower POPF rates. PJ is favored in patients with hard pancreatic texture or larger ducts.
  • Technique Variations: Outcomes depend heavily on technical details (e.g., single-layer vs. double-layer anastomosis, use of stents, or invagination vs. duct-to-mucosa).

 Conclusion

Neither PG nor PJ is definitively superior; both have comparable outcomes in terms of major complications and mortality. PG may offer advantages in reducing POPF in high-risk patients, while PJ remains the standard due to its physiological alignment and widespread use. The decision should be tailored to patient characteristics, surgeon expertise, and institutional protocols. Ongoing research, including RCTs, continues to refine indications for each technique.

📨🏠📝

Antecolique 🆚 Retrocolic

  • AC ↘️ morbidity, DGE & LoS
  • RC 🚫 DGE advantage
  • No difference in DGE
  • RC ↘️ incidence of DGE
  • AC no incidence on DGE & similar outcome to RC

Meta-analyisis / Systematic review

  • Antecolic ↘️ DGE (2 studies)
  • No difference in DGE (3 studies).

The choice between antecolic and retrocolic reconstruction after pancreaticoduodenectomy (Whipple procedure) primarily concerns the route of the gastrojejunostomy or duodenojejunostomy, where the stomach or duodenum is anastomosed to the jejunum. This decision impacts postoperative outcomes, particularly the incidence of delayed gastric emptying (DGE), a common complication after this surgery. Below is a concise comparison based on available evidence:

 Antecolic Reconstruction

  • Definition: The jejunal loop is brought anterior to the transverse colon to create the anastomosis with the stomach or duodenum.
  • Advantages:
    • Lower DGE rates: Studies suggest antecolic reconstruction may reduce DGE incidence compared to retrocolic, potentially due to less compression or kinking of the jejunal loop by the colon. A meta-analysis (e.g., Zhou et al., 2016) reported a lower DGE rate with antecolic (odds ratio ~0.4).
    • Simpler technique: Avoids the need to create a mesenteric window in the transverse mesocolon, potentially reducing operative time and risk of mesenteric complications.
  • Disadvantages:
    • May be associated with longer jejunal loops, potentially increasing the risk of torsion or obstruction in rare cases.
    • Less anatomical positioning, as the jejunum lies over the colon.
  •  

 Retrocolic Reconstruction

  • Definition: The jejunal loop is passed through a window in the transverse mesocolon to lie posterior to the colon for anastomosis.
  • Advantages:
    • Anatomical positioning: Mimics the natural anatomical course, potentially reducing tension on the anastomosis.
    • May be preferred in cases where the mesocolon is thin or when the surgeon aims to minimize jejunal loop length.
  • Disadvantages:
    • Higher DGE rates: Evidence suggests a higher incidence of DGE, possibly due to compression of the jejunal loop by the transverse colon or mesocolon (e.g., Tani et al., 2006, reported 37% DGE in retrocolic vs. 17% in antecolic).
    • Technical complexity: Requires creating a mesenteric window, which may increase the risk of bleeding or injury to mesenteric vessels.

Clinical Evidence

  • Randomized Controlled Trials (RCTs): Studies like Eshuis et al. (2014) and others have shown a trend favoring antecolic reconstruction for lower DGE rates, though some trials report no significant difference in overall morbidity or mortality.
  • Meta-Analyses: A 2018 meta-analysis (Hanna et al.) found antecolic reconstruction associated with a lower DGE incidence (relative risk 0.61, p<0.05) but no significant differences in other complications like pancreatic fistula or length of hospital stay.
  • Other Outcomes: No consistent evidence suggests differences in postoperative complications like anastomotic leaks, infections, or long-term survival between the two techniques.

Current Practice

  • Preference for Antecolic: Many surgeons prefer antecolic reconstruction due to lower DGE rates and technical simplicity, especially in high-volume centers.
  • Surgeon Discretion: The choice often depends on surgeon experience, patient anatomy (e.g., obesity, mesocolon thickness), and institutional protocols.
  • No Universal Standard: While antecolic is increasingly favored, some surgeons still opt for retrocolic in specific cases, such as when anatomical constraints favor a shorter jejunal loop.

Conclusion

Antecolic reconstruction is generally associated with a lower incidence of delayed gastric emptying compared to retrocolic reconstruction, with similar rates of other complications. However, the choice depends on surgeon preference and patient-specific factors. For the most current insights, consulting recent surgical guidelines or discussing with a surgical team is recommended.

📨🏠📝

  • No relevant difference, PPPD is equal to classic PD in term of operative morbidity & mortality. 
  • Oncologic outcome seems equal.
  • Improved DGE is not relevant between both technique.
  • Some data suggest superiority of PPPD in term of DGE and LoS.

The Pylorus-Preserving Pancreaticoduodenectomy (PPPD) and the Classic Pancreaticoduodenectomy (Whipple procedure) are surgical approaches used primarily to treat pancreatic head tumors, periampullary tumors, or other conditions requiring resection of the pancreatic head, duodenum, and surrounding structures. Below is a concise comparison of the two procedures based on their key differences, advantages, and disadvantages:

 Overview

  • Classic Pancreaticoduodenectomy (Whipple): Involves resection of the pancreatic head, duodenum, distal common bile duct, gallbladder, distal stomach (antrum), and sometimes part of the jejunum, followed by reconstruction with gastrojejunostomy, choledochojejunostomy, and pancreaticojejunostomy.
  • Pylorus-Preserving Pancreaticoduodenectomy (PPPD): Similar to the classic Whipple but preserves the pylorus, proximal duodenum, and a portion of the stomach, with reconstruction involving a duodenojejunostomy instead of a gastrojejunostomy.

Key Differences

  1. Pylorus Preservation:
    • Classic Whipple: Removes the distal stomach and pylorus, leading to a direct connection between the remaining stomach and jejunum.
    • PPPD: Preserves the pylorus and proximal duodenum, maintaining more natural gastric emptying and digestive physiology.
  2. Extent of Resection:
    • Classic Whipple: More extensive resection, including part of the stomach.
    • PPPD: Less extensive, sparing the stomach and pylorus.
  3. Reconstruction:
    • Classic Whipple: Gastrojejunostomy (stomach to jejunum).
    • PPPD: Duodenojejunostomy (duodenum to jejunum).

Advantages

  • Classic Whipple:
    • Potentially better oncologic outcomes for certain cancers (e.g., gastric or duodenal involvement) due to wider resection margins.
    • May reduce the risk of marginal ulceration at the anastomosis.
    • Preferred in cases where the tumor involves the distal stomach or pylorus.
  • PPPD:
    • Preserves gastric function, leading to better postoperative nutritional status and weight maintenance.
    • Reduced incidence of dumping syndrome and bile reflux gastritis.
    • Shorter operative time and potentially less blood loss due to less extensive resection.
    • May improve quality of life due to preserved gastric physiology.

Disadvantages

  • Classic Whipple:
    • Higher risk of postoperative nutritional deficiencies due to partial gastrectomy.
    • Increased incidence of dumping syndrome and delayed gastric emptying.
    • More significant alteration of digestive physiology.
  • PPPD:
    • Risk of delayed gastric emptying (DGE), though evidence is mixed and depends on surgical technique.
    • Potentially inadequate resection margins in cases of tumors near the pylorus or stomach.
    • May not be suitable for tumors involving the proximal duodenum or pylorus.

Clinical Outcomes

  • Oncologic Outcomes: Studies show comparable survival rates for pancreatic and periampullary cancers between PPPD and classic Whipple, provided clear margins are achieved. PPPD is often preferred for benign or low-grade malignancies.
  • Complications: Both procedures carry risks of pancreatic fistula, bile leak, and infection. PPPD may have a slightly higher rate of DGE, while the classic Whipple may have more nutritional complications.
  • Recovery: PPPD patients may recover faster and maintain better long-term nutritional status due to preserved gastric function.

Indications

  • Classic Whipple: Preferred for tumors involving the distal stomach, pylorus, or proximal duodenum, or when wider margins are needed for oncologic clearance.
  • PPPD: Preferred for pancreatic head tumors, periampullary tumors, or benign conditions (e.g., chronic pancreatitis) where the pylorus and stomach are not involved.

Conclusion

The choice between PPPD and classic Whipple depends on tumor characteristics, patient factors, and surgeon expertise. PPPD is generally favored for its preservation of gastric function and improved postoperative quality of life, particularly in benign or low-grade malignancies. However, the classic Whipple may be necessary for more extensive tumors or when oncologic margins are a concern. Both procedures require careful patient selection and skilled surgical execution to optimize outcomes.
Disclaimer

This page is designed only for learning support purposes.
It is not dedicated for any medical use or patient care.
HBPSurG makes no claims of the accuracy of the information contained herein.​

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