26/07/2026
π¬ RETROPERITONEAL SARCOMA β SURGICAL TECHNIQUE, TIPS & TRICKS
The single most important sentence in this disease: the best chance of cure is at the FIRST operation. There is no second first chance.
π THE GOVERNING PRINCIPLE
The modern standard is frontline extended (liberal multivisceral) resection β removal of the tumour en bloc with adherent organs and structures even when they are not overtly infiltrated, as a single specimen.
Why: microscopic infiltration of adjacent organs (parenchymal or pericapsular/perivisceral) has been documented in up to 60% of resected organs. What looks "free" at surgery frequently is not.
In experienced centres this policy delivers complete gross resection in ~95%, with 5- and 10-year overall survival of 67% and 46% (TARPSWG, 1007 patients).
β οΈ A grossly incomplete (R2) resection is of questionable benefit and potentially harmful. If you cannot deliver a complete resection, do not start β refer.
π§ 1. BEFORE THE KNIFE β PREOPERATIVE ESSENTIALS
1. CT chest / abdomen / pelvis with IV contrast is the standard staging study.
2. Image-guided percutaneous coaxial core needle biopsy (14β16 G) is strongly recommended. Needle-track seeding risk is minimal and is not a reason to skip biopsy.
3. Never do a laparotomy or open biopsy for a suspected RPS.
4. Assess the contralateral kidney functionally (contrast CT or differential renal scan) β you are planning to take one kidney in roughly half of these cases.
5. Read the CT like a surgeon, not a radiologist: define the asymmetry of retroperitoneal fat, the relation to great vessels, degree of IVC luminal obstruction, and the presence of venous collaterals. These change the operation.
6. Plan in a multidisciplinary sarcoma board. Histology drives the extent of surgery.
π‘ Tip: In low-grade liposarcoma, intraoperative frozen section is useless β the tumour looks exactly like normal fat. Your resection map must come from the preoperative CT.
πΊοΈ 2. THINK IN BARRIERS, NOT IN ORGANS
The retroperitoneum is not a true compartment, but four structures behave as natural barriers to tumour spread:
Posteriorly β muscle sheaths (psoas fascia, quadratus lumborum)
Medially β adventitia of the great vessels
Anteriorly β the peritoneum itself
Where no barrier exists β an organ becomes the margin (colon, mesocolon, distal pancreas)
Dissect OVER the barrier, leaving it on the specimen. This reproduces the logic of compartmental resection in the extremity.
πͺ 3. STANDARD OPERATIVE STEPS
Access: midline laparotomy; extend transversely, obliquely, or thoraco-abdominally for exposure β vascular control is critical and a cramped field is the commonest cause of disaster.
First step: colo-epiploic separation, then division of the transverse colon.
# # # π΅ Right-sided RPS
1. Divide the distal ileum; divide right colic and ileocolic vessels close to the SMA/SMV.
2. Generous Kocher manoeuvre for full access to the IVC.
3. Separate duodenum / pancreatic head from the supero-medial aspect of the tumour, staying very close to the duodenal wall. If a strip of the lateral duodenal wall must go, repair primarily or with a jejunal patch.
4. The right lobe of the liver is usually just elevated. Liver resection is never indicated unless directly invaded; a sub-capsular dissection of the inferior/posterior surface is more often what is needed β with vascular control ready.
# # # π΄ Left-sided RPS
1. Ligate the inferior mesenteric vein at the lower border of the pancreas.
2. Ligate the IMA; divide the sigmoid at the recto-sigmoid junction.
3. Detach the mesocolon from the great vessels.
4. Tumour below the transverse mesocolon β sweep distal pancreas and spleen off the top of the tumour.
5. Tumour extending into the upper left retroperitoneum β divide the distal pancreas, ligate splenic artery and vein, mobilise the spleen en bloc with the upper pole of the tumour.
# # # βοΈ Common to both sides
6. Sub-adventitial dissection of the great vessels from the iliac vessels up to the diaphragmatic hiatus. Ligate and divide aortic/caval collaterals β renal, gonadal, adrenal.
7. Keep the ipsilateral adrenal on the specimen to clear the upper retroperitoneal space.
8. Laterally: incise the parietal wall and leave the peritoneum (Β± the inner layer of the abdominal side wall) on the tumour.
9. Posteriorly: carry the dissection to the psoas. Identify the femoral nerve just above the inguinal ligament after opening the psoas fascia; detach the fascia from the vertebrae and leave it on the back of the tumour.
10. Superiorly: peel the diaphragmatic peritoneum and leave it on top of the tumour.
Final specimen: tumour + kidney + adrenal + ipsilateral colon and mesocolon anteriorly; psoas aponeurosis (or whole psoas) posteriorly; abdominal wall peritoneum laterally/inferiorly; diaphragmatic peritoneum superiorly.
π Typical organ yield in modern series: ipsilateral kidney 55%, colon 25β33%, psoas 27%, spleen 16%, distal pancreas 12%, diaphragm 13%, abdominal wall 12%, iliac vein/IVC 10%. Pancreaticoduodenectomy is required in only 4β5% of right-sided tumours.
𦡠4. PSOAS AND THE RETROPERITONEAL NERVES
Partial or complete psoas resection is needed in ~30% of cases. Know what lies behind it.
Behind the psoas fibres: lumbar arteries and veins, and the L2βL4 roots of the femoral and obturator nerves.
Femoral nerve β the main motor nerve of the retroperitoneum; found postero-laterally on the psoas, just proximal to the inguinal ligament. Long-term functional loss after femoral nerve sacrifice is the one truly disabling morbidity of this operation.
Genitofemoral nerve β on the anterior surface of the psoas; usually has to be divided even for partial psoas/fascial resection β numbness of the anterior thigh. Warn the patient before surgery.
Iliohypogastric nerve β carries motor fibres to the lateral abdominal wall; division produces a permanent bulge (relaxatio) of the abdominal wall.
Lateral femoral cutaneous and ilio-inguinal nerves are purely sensory.
β οΈ Sensory disturbance of thigh, groin or ge***al region is reported long-term by 76% of patients. Consent for it explicitly.
π©Έ 5. MAJOR VASCULAR INVOLVEMENT β WHEN TO RESECT, WHEN TO PEEL
Vascular resection is required in 10β14% of primary RPS β mostly leiomyosarcomas arising from veins.
Decision rule:
Attempt sub-adventitial dissection of the tumour off every major vessel β unless the vessel is widely encased or overtly infiltrated.
The adventitia, left on the tumour side, is a genuine oncological barrier and a safe dissection plane. Systematic vascular resection has never been shown to improve local control or survival, and it roughly doubles the risk of severe postoperative adverse events.
β οΈ Trap: peri-tumoural inflammation and desmoplastic reaction are frequently indistinguishable from true wall invasion. Also, a vessel that is merely pushed and thinned may need resection simply to avoid or control a catastrophic tear.
# # # Arterial reconstruction
Primary anastomosis is rarely possible after an oncological resection β orthotopic prosthetic graft (ring-reinforced PTFE, or Dacron) is standard; patency >90%.
Reversed great saphenous vein is an option for visceral/iliac arteries.
If colon or bowel is resected in the same operation: consider an extra-anatomic route (cross-femoral or axillo-bifemoral bypass), silver- or antibiotic-impregnated grafts, and always interpose omentum between graft and viscera.
SMA encasement is generally a marker of unresectability; segmental SMA resection is exceptional.
# # # Venous / IVC reconstruction
Partial wall defect,