Lieno renal shunt anesthesia

1. ANAESTHESIA FOR EHPVO AND LIENO-RENAL SHUNT
-Dr. Ravikiran H M
Indira Gandhi Institute of Child Health
Introduction:
 Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO)
are non-cirrhotic vascular causes of portal hypertension (PHT).
 Extrahepatic portal venous obstruction (EHPVO) is the commonest cause of portal
hypertension and variceal bleeding in children.
 In contrast to cirrhosis, both the conditions are associated with normal or mildly elevated
hepatic venous pressure gradient (HVPG) with high portal venous pressure gradient between
portal vein (PV) and inferior vena cava.
 These are dominantly vasculopathies, with the involvement of PV (portal vein) or its
tributaries with minimal parenchymal injuries.
 The site of resistance to blood flow is presinusoidal and perisinusoidal in IPH, while it is
prehepatic in EHPVO.
The similarities and differences of IPH and EHPVO are highlighted in Table:
IPH EHPVO
Similarities  Incidence higher in third world countries
 Gastrointestinal infections postulated as etiological link
 Prothrombotic predisposition
 Liver acinar architecture maintained on histology
 Manifest clinically as portal hypertension (variceal bleed,
splenomegaly)
 Normal liver enzymes and synthetic functions
 Esophageal, gastric, and colorectal varices are frequently present
 Portal biliopathy commoner than in cirrhotics
 Natural course is benign except from variceal bleed episodes
 Excellent long-term prognosis
 Late decompensation due to parenchymal extinction
Age of onset 3-5th
decade 1-2nd
decade
First variceal
bleed (mean age)
30y 5y
Etiological factors  Infections
 Prothrombotic states
 Drugs and toxins
 Immunological
 Genetic
 Infections
 Prothrombotic states
 Congenital anomalies

2. Pathology  Obliterative portal venopathy
 Portal angiomatosis
 Periportal and perisinusoidal
fibrosis
 Cavernomatous transformation
of PV
 None or Portal fibrosis
Clinical and laboratory features
Liver size Normal in 2/3, Shrunken in 1/3 Normal
Jaundice 9-31% rare
Ascites 10–34% 10% (after variceal bleed)
Hypersplenism 27-87% 22-70%
Liver stiffness
(FibroScan)
7.8–10.2 kPa 5.9 kPa
Hyperdynamic
circulation
+ ++
Autonomic
dysfunction
25% 67%
Radiological
features (on
Doppler)
Prominent SPA, dilated PV with
thick walls, cutoff of intrahepatic
second- and third-degree PV
branches (withered tree
appearance)
Cavernoma formation (PV replaced
by a bunch of collaterals)
Portal biliopathy
Hemodynamics
WHVP (wedge
hepatic venous
pressure)
Normal or mildly elevated Normal
FHVP (free
hepatic venous
pressure)
Normal Normal
HVPG (hepatic
venous pressure
gradient)
Normal or up to 10 mmHg Normal (< 5 mmHg)
Natural history
Parenchymal
extinction
9–19% 21%
Portal biliopathy 9–40% 80-100%
Minimal hepatic
encephalopathy
Not known 32–35%
Growth
retardation
Not studied 31–57%
Quality of life Not studied Impaired
Note: CAVERNOMA: Multiple tortuous hepatopetal collaterals, which develop around and inside
the thrombus within the PV.

3. Pathogenetic theories and etiological factors in IPH and EHPVO:
1. Unifying hypothesis, a major thrombotic event occurring at a young age involves main
PV resulting in EHPVO, whereas repeated microthrombotic events later in life involve
small or medium branches of PV leading to IPH.
2. Dual theory explains development of IPH secondary to increased splenic blood flow
secondary to high inducible nitric oxide synthase (iNOS) and intrahepatic obstruction .
3. Endothelial–mesenchymal transition (EndMT) theory says that vascular endothelial
cells of portal venules acquire myofibroblastic features leading to collagen synthesis and
subsequent occlusion of small PV branches.
Etiological factors for IPH Etiological factors for EHPVO
1. Infections: HIV, Bacterial, protozoal,
schistosomiasis
2. Drugs & Toxins: Arsenic, vinyl chloride,
CuSO4, Mtx, 6-MP, azathioprine,
didanosine, irradiation, vitamin-A
3. Prothrombotic states: MPD (+ JAK2
mutation), MTHFR deficiency, protein-C
& S deficiency, ACLA, prothrombin gene
mutation, ADAMTS13 deficiency
4. Immunological: SLE, Scleroderma,
autoimmune thyroiditis, celiac disease,
rheumatoid arthritis, multiple sclerosis,
POEMS syndrome, Celiac disease, primary
hypogammaglobulinemia
5. Genetic:HLADR3, Turne r’s,Noonan
&Adams - Oliver syndromes, KCNN3
mutation
1. Congenital anomalies: Portal vein atresia,
associated cardiovascular, urinary, limb
anomalies, cleft lip & palate
2. Systemic prothrombotic states:
 Genetic: MTHFR deficiency, prothrombin
gene mutation, factor-V Leiden, protein-C,
S, antithrombin-III deficiency,
 Acquired: Diarrhea, Nephrotic syndrome,
oral contraceptives, ACLA or APLA
3. Local conditions:
 Infections: Omphalitis, liver abscess,
pyelephlebitis, pancreatitis, cholangitis,
neonatal sepsis, necrotizing enterocolitis
 Surgery: Billroth-II, splenectomy,
cholecystectomy, surgery of duodenum,
pancreas or bile ducts
 Trauma: Umbilical vein catheterization

5. Natural history of IPH and EHPVO:
1. Splenomegaly
2. Variceal bleed
3. Hypersplenism
4. Growth failure
5. Portal biliopathy
6. Minimal hepatic encephalopathy
7. Parenchymal extinction (Decompensation)
Portal biliopathy:
It refers to the biliary ductal (extraheaptic and intrahepatic) and gall bladder wall abnormalities
in patients with cirrhotic or noncirrhotic PHT, taking the form of intrahepatic biliary radicles
dilatation, indentations, caliber irregularities, displacements, angulations, ectasias, strictures,
stones, filling defects, compressions, gall bladder, and pericholedochal varices or a mass
(pseudo-cholangiocarcinoma sign).
The definition needs exclusion of other biliary diseases.
Pathogenesis is related to two mechanisms:
1. Compression of the pliable common bile duct (CBD) by dilated collaterals.
2. Neovascularisation secondary to long-standing PVT(portal vein thrombosis), and bile
duct ischemia either due to prolonged compression by collaterals, thrombosis of smaller
veins draining the duct, or excessive deposition of connective tissue forming a ‘‘tumor-
like’’ cavernoma .
Compression of paracholedochal venous plexus leads to varicoid type of PB involving entire
biliary system giving a wavy or undulating contour, and may show favourable response
following shunt surgery.
Contrastingly, chronic inflammation and ischemia lead to scarring of bile duct wall causing
fibrotic type of PB producing single or multiple segmental strictures with upstream dilatation, the
changes which are possibly non-reversible
Management:
Key management issues are varices, splenomegaly, hypersplenism, growth failure, portal
biliopathy, MHE, and poor quality of life.

7. Role of surgery:
Most of the IPH are easily manageable with successive endotherapies; hence, there are very few
indications for surgery—uncontrolled or recurrent variceal bleed, or bleeding from ectopic sites.
Moreover, there are long-term risks of MHE, glomerulonephritis, pulmonary arteriovenous
fistula, and ascites following shunt procedure in IPH.
On the other hand in EHPVO, with advancement in technical expertise, surgery is gradually
becoming the first line treatment.
Meso-Rex shunt or Mesenterico-left portal vein bypass (MLPVB), decompresses superior
mesenteric vein into left branch of PV (LPV) (left portal vein) via anautologous graft (eg. IJV),
is the surgical shunt of choice in EHPVO.
This shunt restores hepatic portal blood flow in the closest possible physiological manner, and in
a long run protects liver from parenchymal extinction.
In the absence of a patent Rex vein (LPV), the indications for shunt should be carefully looked
for.
Non-physiological portosystemic shunts are still worldwide the commonest surgeries performed
for EHPVO.
From the South-east Asian region, there is vast literature on feasibility, patency, and long-term
outcomes of these shunt surgerie. However, in a recent report, the long-term patency has been
questioned.
While non-selective shunts like proximal splenorenal shunt (PSRS) decompress whole system
taking care of PB as well, the distal splenorenal shunt (DSRS) takes care of the left-sided
(sinistral) PHT.
In younger children, there are issues related to technical feasibility and shunt thrombosis, but
these have been largely overcome with improvement in surgical expertise.
With Rex shunt, the patency rates are slightly lower than traditional shunts. However, in addition
to causing improvements in spleen size, hypersplenism, varices, growth, and portal biliopathy,
Rex shunt, in contrast to non-physiological shunts, also leads to improvement in liver volume,
MHE and neuro-cognitive outcome in the long term, and, hence, is now the surgery of choice in
applicable settings.
Surgical ablative procedures, like esophageal devascularization and transection or
splenectomy, were used in the past for uncontrolled torrential or recurrent bleeds, or with failed

8. shunts or absent shuntable veins. These have become obsolete now with advances in endoscopic
and radiological techniques
Liver transplantation: Around 6% of patients with IPH may need.
Note:
SURGICAL OPTION
Shunt surgery Non-Shunt surgery
Physiologic shunts
(restoring blood flow
back to liver)
Nonphysiologic
shunts (diverting
blood away from
liver)
meso-Rex shunt
(bypass)
i. Selective shunts
ii. Nonselective
shunts
1. Partial shunting of
portal blood
2. Complete shunting
of portal blood
a. Surgical ligation of varices
b. Sugiura procedure and others (Esophageal
Transaction and Reanastomosis)

10. Meso-Rex shunt or Mesenterico-left portal vein bypass (MLPVB):
Pre-requisite: patent Rex vein
Venous conduit: IJV, saphenous vein, coronary vein, IMV or synthetic grafts
Proximal splenorenal shunt (PSRS):
Indication: EHPVO, IPH
Preop prep:
Doppler size of splenic vein, left renal vein
Vaccination
Arrange adequate blood
Incision: Left subcostal or left thoraco-abdominal
Mitra shunt: spleen preserving, side to side lieno-renal shunt: suitable for infants
Role of interventional radiology techniques:
1. Transjugular intrahepatic portosystemic shunt (TIPSS) is now considered feasible in a
non-cirrhotic PVT, the indications being PHT complications (recurrent bleed, refractory
ascites) getting difficult to manage medically, or need of anti-coagulation in the presence
of large varices.
2. Partial splenic artery embolization (PSE) is sometimes offered as a relative safe
alternative to splenectomy for hypersplenism.
3. Percutaneous transhepatic biliary drainage (PTBD) is done in settings of cholangitis or
choledocholithiasis secondary to portal biliopathy when endoscopic techniques have
failed.
4. Shunt reduction or closure can be done using coils or balloon occluded trans-venous
obliteration.
Role of anti-coagulation:
In IPH with PVT, anti-coagulation usage has been shown to recanalize thrombus in half of the
patients.
Presence of underlying prothrombotic state in IPH or EHPVO, anti-coagulation can be started
taking into consideration the risk of bleeding from the varices..
Management of portal biliopathy:

11. Biliary diversion procedures are rarely needed in case the symptoms of biliary obstruction persist
after shunt.
Anaesthesia consideration:
 EHPVO is common in pediatric age group
 Growth retardation, decrease lean body mass and loss of muscle that may lead to
postoperative respiratory failure
 Upper abdominal surgery with severe pain may compound the problem of pulmonary
atelectasis.
 Poor preoperative nutritional status and anemia may lead to delayed wound healing, delayed
ambulation, and respiratory complications.
 To avoid postoperative respiratory complications insert epidural catheter weighing the
possibility of epidural space bleed due to low platelet counts, anticoagulant therapy.
 Degree of hepatic dysfunction : drug dosing, type of shunt (no Rex shunt if cirrhosis)
 Hypersplenism: thrombocytopenia, need for spleenectomy
 Variceal bleed: Patient will be on propranolol, repeated endoscopy for sclerotherpy/banding,
careful when inserting Ryle’s tube, TEE
 Growth retardation: malnutrition, anemia, prone to infection
 Ascitis: need RSI, Paracentasis induced cardiac dysfunction (PICD)
 Pleural effusion: need tapping just prior surgery
 Porto-pulmonary HTN
 Hepatopulmonary syndrome
 Hepato renal syndrome
 Encephalopathy: careful when premedicating
 Cardiomyopathy
 Two large bore peripheral IV cannula preferably upper limb
 Central line: decide location based on IJV graft requirement(if planning IJV CVP), IVC
anastamosis or injury during surgery so clamping may be required (of planning femoral
CVP)

12.  As it’s a vascular surgery plan for Massive transfusion & cell salvage. Fluid warming device-
Hot line.
 Splanchnic vasoconstriction and thrombosis leading to intestinal ischemia must be avoided
with adequate cardiac output, oxygen delivery and decreasing release of stress hormones. It
is recommended that thrombophilia be ruled out in cases of EHPVO and anticoagulation
therapy should be started early in the prothrombotic state especially to maintain the patency
of shunt.
Monitoring:
 Routine ASA
 IBP: vascular surgery, major fluid shift
 Blood glucose: patient already malnourished, hepatic dysfunction
 ABG, Hemoglobin, serum electrolyte: prolonged surgery, bleeding, fluid shift
 ACT/ coagulation profile: for heparin, liver dysfunction, massive transfusion
 Temperature: patients are typically thin with little or no body fat and active heat support
should be provided as soon as possible
 Urine output: adequate perfusion
Postoperative issues:
 Shunt thrombosis: need anticoagulation
 Post shunt/Portosystemic encephalopathy
 Post spleenectomy sepsis
 Increased cardiac output
 Significant abdominal bleeding necessitates emergent reoperation
 Chylous ascites : because of disruption of retroperitoneal lymphatic channels.
 Esophageal strictures after devascularization procedures and esophageal transection are
common.

13. CVS consequences of portocaval shunt:
PORTOCAVAL SHUNT
↓ ↓ ↓
Redistribution of flow to
surgical shunt
↓ resistance to portal flow ↓portal flow to the liver
(↑hepatic arterial blood flow)
↓
↓ ↓
↓ arterial resistance in the gut
& spleen
↓total hepatic blood flow
↓ ↓
↑ blood flow to the gut &
spleen
↑ Vasoactive intestinal
polypeptide, Glucagon
↓ ↓
↑ flow to inferior venacava ↓ Total peripheral vascular
resistance
↓ ↓
↑venous return ↑ ejection fraction
↓ ↓
↑ cardiac output
References:
1. Barasch 5th
ed
2. Idiopathic portal hypertension and extrahepatic portal venous Obstruction. Hepatology
International (2018) 12 (Suppl 1):S148–S167
3. ANAESTHETIC MANAGEMENT OF EXTRAHEPATIC PORTAL VENOUS
OBSTRUCTION. Bali Journal of Anesthesiology (BJOA) 2018, Volume 2, Number 3:
102-104
4. Surgery for Portal Hypertension in Children. Curr Gastroenterol Rep (2011) 13:279–285