Portal hypertension: A critical appraisal of shunt procedures with emphasis on distal splenorenal shunt in children

Use of caudal pancreatectomy as a novel adjunct procedure to proximal splenorenal shunt in patients with noncirrhotic portal hypertension: A retrospective cohort study

Backgrounds/Aims

Proximal splenorenal shunt (PSRS) is considered a one-time treatment for noncirrhotic portal hypertension (NCPH) to prevent recurrent upper gastrointestinal (UGI) hemorrhage and long-term complications. Long-term shunt patency is necessary to achieve these. The lie of the shunt is a contributing factor to early shunt thrombosis. We investigated the role of resection of the distal tail of pancreas (caudal pancreatectomy [CP]) in improving the lie of shunt and decreasing shunt thrombosis.

Methods

This was a retrospective cohort study of patients with NCPH who underwent PSRS between 2014-2020 in JIPMER, Puducherry, India. CP was performed in patients with a long tail of pancreas, with the tip of pancreatic tail extending up to splenic hilum on preoperative CT. Perioperative parameters and shunt patency rate of patients who underwent PSRS with CP (Group A) were compared with patients undergoing conventional PSRS (Group B). Statistical analysis was performed using the Mann-Whitney U test and χ² test.

Results

Eighty four patients with NCPH underwent PSRS (extrahepatic portal vein obstruction = 39; noncirrhotic portal fibrosis = 45). Blood loss was lower (p = 0.002) and post-shunt fall in portal pressure higher (p = 0.002) in Group A. Shunt thrombosis rate was lower (p = 0.04) while rate of complete variceal regression (p = 0.03) and biochemical pancreatic leak (p = 0.01) were higher in Group A.There was no clinically relevant pancreatic fistula in either group.

Conclusions

CP is a safe and useful technique for reducing shunt thrombosis after PSRS in patients with NCPH by improving the lie of shunt.

Unconventional Shunts in Extrahepatic Portal Venous Obstruction-A Retrospective Review

Background

Proximal splenorenal shunt (PSRS) is one of the most commonly performed portosystemic shunt (PSS) in extrahepatic portal venous obstruction (EHPVO) for portal decompression. Sometimes various anatomical and surgical factors related to the splenic vein and/or left renal vein may make the construction of a PSRS difficult or impossible. Unconventional shunts are required to tide over such conditions.

Methods

From January 2008 to December 2018, 189 patients with EHPVO underwent PSS, of which, the 10 patients who underwent unconventional shunts form the study group of this paper.

Results

The ten unconventional shunts included 8 proximal splenoadrenal shunts, one collateral-renal shunt, and one inferior mesenteric vein to inferior vena cava (IMV-Caval) shunt. The mean percentage drop in omental pressure was 34.2% post-shunt with a mean anastomotic diameter of 13.7 ± 3.1 mm. Three patients experienced some form of postoperative complication. With a mean follow-up period of 32.3 months (maximum of 111 months) all patients had patent shunts on follow-up Doppler. None of the patients had variceal bleed, or features of biliopathy and hepatic encephalopathy in follow-up.

Conclusion

Unconventional shunts can be used safely and effectively with good postoperative outcomes in EHPVO.

H-shaped partial splenorenal shunting with the use of a reinforced graft made of porous polytetrafluoroethylene

AIM

The study was aimed at improving the immediate and remote results of splenorenal bypass grafting.

PATIENTS AND METHODS

A total of 57 patients presenting with hepatic cirrhosis, portal hypertension, and recurrent haemorrhage from oesophageal varices underwent an H-shaped partial splenorenal shunt procedure using an externally reinforced 1.5-2.0-cm-long synthetic graft with a diameter equalling half of that of the splenic vein in an end-to-side fashion. Assessment of efficacy of shunting was based on intraoperative measurement of venous pressure in the portal system before and after shunting, the findings of Doppler ultrasonography of the linear velocity of blood flow in the portal, splenic, and left renal veins in the early postoperative period, as well as computed tomography, esophagogastroscopy, and assessment of the degree of hepatic encephalopathy in the remote postoperative period.

RESULTS

The findings of intraoperative measurement of venous pressure in the portal vein system before and after shunting demonstrated a statistically significant decrease in (normalization of) portal pressure in all patients after bypass grafting (p≤0.05). There were no severe postoperative complications, in-hospital mortality, nor events of decompensation of hepatic insufficiency. According to the findings of Doppler ultrasonography of the linear velocity of blood flow and control computed tomography after surgery, the splenic vein, left renal vein and the conduit between them remained patent at all terms of postoperative follow up. The findings of control esophagogastroscopy revealed a statistically significant decrease in the degree of oesophageal varices at 3, 6, and 9 months after shunting (p≤0.05). There was no statistically significant difference in the change of the degree of hepatic encephalopathy at 3, 6, and 9 months after shunting (p=0.853, p=0.712, and p=0.581, respectively). At various terms after surgery, nine patients underwent deceased donor liver transplantation, with the splenorenal shunt ligated intraoperatively.

CONCLUSION

This method of splenorenal shunting makes it possible to decrease the risk of bleeding from oesophageal varices and venous thromboses in vascular anastomoses, as well as complications resulting from using autovenous conduits, to decrease the risk of decomposition of hepatic insufficiency and the frequency of the development of encephalopathy in the postoperative period. Besides, this method makes it possible to easily dismantle the previously created artificial portocaval shunt in the process of liver transplantation.

Noncirrhotic Portal Hypertension: Current and Emerging Perspectives

Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are prototype noncirrhotic causes of portal hypertension (PHT), characterized by normal hepatic venous pressure gradient, variceal bleeds, and moderate to massive splenomegaly with preserved liver synthetic functions. Infections, toxins, and immunologic, prothrombotic and genetic disorders are possible causes in IPH, whereas prothrombotic and local factors around the portal vein lead to EHPVO. Growth failure, portal biliopathy, and minimal hepatic encephalopathy are long-term concerns in EHPVO. Surgical shunts and transjugular intrahepatic portosystemic shunt resolve the complications secondary to PHT. Meso-Rex shunt is now the standard-of-care surgery in children with EHPVO.

Clinical and Imaging Predictors of Surgical Splenorenal Shunt Dysfunction in Pediatric Patients

PURPOSE

Few established criteria exist to prompt angiographic evaluation and intervention for surgically created splenorenal shunts (SRS). Clinical and Doppler ultrasound (DUS) imaging predictors of shunt dysfunction were evaluated in this retrospective study.

MATERIALS AND METHODS

Consecutive patients undergoing SRS angiography over a 10-year period were retrospectively identified. Preangiography platelet count and DUS measurements of spleen diameter, maximum splenic vein velocity, and maximum shunt velocity were assessed and compared to findings at subsequent catheter angiography.

RESULTS

Twenty-six SRS angiograms were performed in 16 patients. Two of the 26 procedures were excluded from analysis due to insufficient baseline preangiography clinical and DUS data. In the remaining 24 cases, significant stenosis/occlusion was confirmed at angiography in 20, whereas wide patency was seen in 4. For the 20 cases of angiographically confirmed significant stenosis/occlusion, when compared to baseline post-SRS creation to immediate preangiography evaluation there was a greater decrease in platelet count (-51.8% vs -19.4%), a greater increase in spleen diameter (+13.4% vs +3.7%), a greater increase in maximum shunt velocity (+74.7% vs +59.7%), and a greater decrease in splenic vein velocity (-25.0% vs -18.5%).

CONCLUSION

Clinical evidence of splenic sequestration and DUS finding of increased maximum shunt velocity correlate with angiographic findings of SRS dysfunction and could be used to help predict the need for shunt intervention.

Idiopathic portal hypertension and extrahepatic portal venous obstruction

BACKGROUND

Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are non-cirrhotic vascular causes of portal hypertension (PHT). Variceal bleed and splenomegaly are the commonest presentations.

AIM

The present review is intended to provide the existing literature on etiopathogenesis, clinical profile, diagnosis, natural history and management of IPH and EHPVO.

RESULTS

IPH and EHPVO are both characterized by normal hepatic venous pressure gradient, moderate to massive splenomegaly with preserved liver synthetic functions. While the level of block in IPH is presinusoidal, in EHPVO it is at prehepatic level. Infections, autoimmunity, drugs, immunodeficiency and prothrombotic states are possible etiological agents in IPH. Contrastingly in EHPVO, prothrombotic disorders and local factors around the portal vein are the incriminating factors. Diagnosis is often clinical, supported by simple radiological tools. Natural history is defined by episodes of variceal bleed and symptoms related to enlarged spleen. Growth failure, portal biliopathy and minimal hepatic encephalopathy are additional concerns in EHPVO. Long-term survival is reasonably good with endoscopic surveillance; however, parenchymal extinction leading to decompensation is seen in a minority of patients in both the disorders. Surgical shunts revert the complications secondary to PHT. Meso-Rex shunt has become the standard surgery in children with EHPVO.

CONCLUSION

This review gives a detailed summary of these two vascular conditions of liver-IPH and EHPVO. Further research is needed to understand the pathogenesis and natural history of these disorders.

High patency of proximal splenorenal shunt: A myth or reality ? - A prospective cohort study

BACKGROUND

Proximal splenorenal shunt (PSRS) is a well-accepted surgical procedure for non-cirrhotic portal hypertension (NCPH). Though a patent shunt is important for good long term outcome, there are very few studies on patency of these shunts. We analysed shunt patency using dynamic computed tomographic (CT) portography and compared it with other modalities.

METHODS

From 2004 to 2014, 50 patients with PSRS were evaluated prospectively for shunt patency using dynamic CT portography, clinical parameters and ultrasound Doppler.

RESULTS

The causes of NCPH were extrahepatic portal vein obstruction (EHPVO) in 38 patients and non-cirrhotic portal fibrosis (NCPF) in 12 patients. The shunt patency rate using clinical parameters, ultrasound Doppler and dynamic CT portography were 70%, 40% and 60% respectively. Clinical parameters overestimated while ultrasound Doppler underestimated the shunt patency rate. Dynamic portography had 100% correlation with conventional angiography in the five patients when this was done. The site of shunt could be demonstrated convincingly by dynamic CT portography. The shunt patency rate decreased over time. It was 64%, 60% and 43% in <1 year, 1-5 years and >5 years respectively. Our NCPF patients had a greater shunt patency rate compared to EHPVO patients (9/12 vs. 21/38) though the difference was not significant. Only size of the splenic vein had a significant impact on the shunt patency rate on statistical analysis.

CONCLUSIONS

Dynamic CT portography is useful for evaluation of shunt patency. Proximal splenorenal shunts have a high blockage rate which has hitherto not been reported.