What is a proximal splenorenal (PSRS) shunt and how is it performed?

Proximal Splenorenal Shunt: Definition and Surgical Technique

A proximal splenorenal shunt (PSRS) is a surgical portosystemic shunt that connects the splenic vein to the left renal vein after splenectomy, creating complete portal decompression to treat portal hypertension and prevent variceal bleeding. 1

Definition and Purpose

The proximal splenorenal shunt, first introduced by Robert Linton in 1947, remains an important surgical option for managing portal hypertension, particularly in:

• Patients with non-cirrhotic portal hypertension (NCPH)
• Cases with refractory variceal bleeding
• Patients with hypersplenism
• Situations where endoscopic or radiologic interventions have failed

Unlike the distal splenorenal shunt (Warren procedure), which preserves the spleen and maintains selective portal decompression, the proximal splenorenal shunt involves complete splenectomy and creates total portal decompression.

Surgical Technique

Standard Procedure (Linton's Technique):

1. Patient positioning and incision:

   • Patient placed in supine position
   • Left subcostal or midline incision

2. Splenectomy:

   • Mobilization of the spleen
   • Ligation of splenic artery and vein at the hilum
   • Complete removal of the spleen

3. Vascular dissection:

   • Careful isolation of the splenic vein stump
   • Identification and mobilization of the left renal vein
   • Creation of adequate length for both vessels to allow tension-free anastomosis

4. Anastomosis:

   • End-to-side anastomosis between the splenic vein and left renal vein
   • Use of fine non-absorbable sutures (typically 5-0 or 6-0)
   • Ensuring patency and adequate flow through the anastomosis

Modified Technique (Omar's Technique):

A simplified approach described by Omar involves dissection of the fusion fascia of Toldt, which offers several advantages 2:

• Better vascular control
• Easier dissection of the splenic vein
• Reduced intraoperative blood loss
• Shorter operative time
• Technically less demanding

Efficacy and Outcomes

The proximal splenorenal shunt has demonstrated excellent outcomes:

• Long-term control of hemorrhage achieved in 97-100% of patients 1
• Significant reduction in portal pressure
• Effective reversal of hypersplenism
• Low operative mortality rates (0.7% for elective procedures) 3
• Excellent long-term survival (15-year survival rate of 95% in children with extrahepatic portal venous obstruction) 3

Complications and Considerations

Important considerations for PSRS include:

• Hepatic encephalopathy: Higher risk due to complete portal diversion 1
• Loss of hepatopetal portal flow: Occurs in most patients 1
• Technical challenges: May require alternative approaches when anatomical variations exist 4, 5
• Post-splenectomy infection risk: Requires appropriate vaccination
• Shunt thrombosis: Requires monitoring for patency

Alternative Approaches

When standard PSRS is not feasible due to anatomical variations or technical difficulties, alternative unconventional shunts may be considered 4:

• Splenoadrenal shunt (SAS)
• Interposition mesocaval shunt (iMCS)
• Interposition PSRS (iPSRS)
• Jejunal vein-cava shunt (JCS)
• Left gastroepiploic-renal shunt (LGERS)

Modern Context

While PSRS remains effective, it should be noted that current management of portal hypertension has evolved to include:

• Transjugular intrahepatic portosystemic shunt (TIPS)
• Balloon-occluded retrograde transvenous obliteration (BRTO)
• Endoscopic management

PSRS should be performed at centers with substantial experience operating in the setting of pressurized varices, such as liver transplant centers 1.

In recent years, laparoscopic approaches to PSRS have been developed, offering minimally invasive alternatives in selected cases 6.