Hyperthermic Intraperitoneal Chemotherapy

HIPEC: The Basics - Scalpel & Suds

• Definition: Heated (41-43°C) chemotherapy delivered directly into the peritoneal cavity during surgery.
• Synergy: Used as an adjunct immediately after Cytoreductive Surgery (CRS) for peritoneal malignancies.
• Objective: Eradicate microscopic residual disease (MRD) not visible to the surgeon, aiming to improve survival.
• Distinction: Differs from EPIC (Early Postoperative Intraperitoneal Chemotherapy), which is typically normothermic and administered in the early postoperative period.

⭐ HIPEC targets microscopic disease not visible to the surgeon after CRS.

HIPEC Indications - Targeting Tumors

Prerequisite: Complete Cytoreduction (CC-0/CC-1). Peritoneal Carcinomatosis Index (PCI) guides selection.

• 📌 P-A-C-O-M Indications & typical PCI cut-offs:
  • Pseudomyxoma peritonei (PMP): Favorable, higher PCI may be accepted.
  • Appendiceal cancer (peritoneal mets): PCI < 20.
  • Colorectal cancer (peritoneal mets, selected): PCI < 12-15 (up to 20).
  • Ovarian cancer (recurrent/selected primary): PCI < 10-15.
  • Mesothelioma (peritoneal): PCI < 30.

⭐ Pseudomyxoma peritonei: classic, highly favorable for CRS + HIPEC.

HIPEC Mechanics - Hot Chemo Action

• Hyperthermia Rationale (Target: 41‑43°C intra-abdominally):
  • ↑ Drug penetration into tumors
  • Direct cytotoxicity from heat
  • Inhibits DNA repair mechanisms
  • Synergistic action with chemotherapy
• Pharmacological Advantages:
  • High local drug concentration (peritoneal)
  • ↓ Systemic absorption & toxicity
  • Helps overcome drug resistance
• Common Chemotherapy Agents:
  • Mitomycin C, Cisplatin, Oxaliplatin, Doxorubicin
  • Selection factors: Tumor type, drug heat stability, molecular weight.

⭐ Hyperthermia at 41-43°C significantly enhances the cytotoxic effect of drugs like Mitomycin C and Cisplatin on peritoneal tumor cells.

HIPEC Procedure - The Surgical Dance

• Prerequisite: Maximal Cytoreductive Surgery (CRS) achieving CC-0 (no visible disease) or CC-1 (nodules < 2.5mm).
• Techniques:
  • Open (e.g., Coliseum, Sugarbaker technique) or Closed abdomen methods.
  • Heated chemotherapy (e.g., Mitomycin C, Cisplatin) perfused for 60-90 minutes.
• Key Steps:
  • Strategic placement of inflow/outflow catheters.
  • Establishment of perfusion circuit; continuous multi-site temperature monitoring.
• Safety: Intraoperative measures to minimize staff exposure to cytotoxic agents.

⭐ The completeness of cytoreduction (CC score) before HIPEC is the single most important prognostic factor for long-term survival.

HIPEC: Candidates & Caveats - Risk vs Reward

• Candidates: ECOG 0-1; resectable disease (low PCI, CC 0/1 achievable); adequate organ function; limited extra-abdominal disease.
• Contraindications: ECOG ≥2-3; unresectable (high PCI, extensive small bowel); significant comorbidities; active infection.
• Risks: Morbidity 20-40% (Grade III/IV: hematologic, GI, renal); Mortality <5% (experienced centers).

⭐ Major postoperative morbidity after CRS/HIPEC can be 30-40%, demanding careful selection & experienced teams.

High‑Yield Points - ⚡ Biggest Takeaways

• HIPEC is cytoreductive surgery (CRS) plus heated (41‑43°C) intraperitoneal chemotherapy for locoregional control.
• Main uses: Pseudomyxoma peritonei, peritoneal mesothelioma, ovarian/colorectal peritoneal metastases (PM).
• Hyperthermia enhances drug penetration and cytotoxicity.
• Common agents: Mitomycin C, Cisplatin, Doxorubicin.
• Targets microscopic residual disease after optimal CRS.
• Offers improved progression‑free and overall survival in selected patients.
• Key complications: Anastomotic leak, ileus, myelosuppression, renal toxicity.