Perioperative management for hepatic resection surgery
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Tags: Hepatic resection
Abstract
Notes
Annotations
(7/20/2022, 11:28:00 PM)
“The liver parenchyma has the unique ability to regenerate via hyperplasia of the hepatocytes. This process commences within 24 h of resection with the liver typically reaching its original size by 6 months. However, complete functional recovery may occur within 2e3 weeks” Go to annotation (Patel et al., 2022, p. 2)
“eTurcotteePugh (CTP) system divides cirrhosis into three classes; A e least severe; B e moderate; C e most severe. It correlates strongly with mortality after hepatectomy. Class C is considered an absolute contraindication to surgery whereas patients of Class A are generally considered good candidates for hepatic resection. Although some Class B patients may undergo resection, the risks are significantly increased, and a limitation of the CTP system is in discriminating within this group.10 The model of end-stage liver disease (MELD) score is also used to predict perioperative risk in patients with CLD or endstage liver disease. Whilst there is no clear cut-off level for elective surgery, a score between 10 and 15 is associated with increased risk.” Go to annotation (Patel et al., 2022, p. 2)
“Future liver remnant of 20% is considered the minimum safe volume for patients with normal liver function, whereas 30-40% is required for patients who have severe steatohepatitis or have received hepatotoxic chemotherapy. At least 50% is necessary for patients with cirrhosis.” Go to annotation (Patel et al., 2022, p. 2)
“Several strategies have been developed to generate compensatory hypertrophy of the FLR and reduce the risk of PHLF. Techniques used currently include portal vein embolisation (PVE); portal vein ligation and associating liver partition and portal vein ligation for staged hepatectomy (ALPPS); and liver venous deprivation (LVD).” Go to annotation (Patel et al., 2022, p. 3)
“The main tenet of anaesthesia for hepatic resection surgery is to optimise the patient’s haemodynamic status using judicious fluids and vasoactive agents in order to create conditions that minimise hepatic venous blood loss whilst maintaining end-organ perfusion.” Go to annotation (Patel et al., 2022, p. 3)
“The requirement for invasive monitoring depends upon the patient’s characteristics, size of resection, surgical approach (minimally invasive or open) and duration of the procedure. Blood loss can be sudden and catastrophic, and blood products should be readily available. Hypothermia should be avoided.” Go to annotation (Patel et al., 2022, p. 3)
“Thoracic epidural analgesia (TEA)dtraditionally the gold standard in open liver resectiondis no longer recommended in ERAS guidelines after the emergence of evidence suggesting alternative techniques are equally effective. A balanced, multimodal, opioid-sparing approach comprising regional techniques and analgesic adjuncts is currently favoured. Considerations include:
“Paracetamol: despite fears of hepatotoxicity, paracetamol appears to be safe in all but the most extensive resections. Risk factors for hepatotoxicity include liver disease, age, malnutrition and intraoperative liver ischaemia.” Go to annotation (Patel et al., 2022, p. 3)
“NSAID: these are effective and opioid-sparing. They should be used if not contraindicated.” Go to annotation (Patel et al., 2022, p. 3)
“IV opioid - reducing the use of opioids decreases the incidence of their adverse effects (e.g. PONV, respiratory depression) and promotes postoperative recovery. Despite this they remain in common use both during and after surgery.” Go to annotation (Patel et al., 2022, p. 3)
“thoracic epidural analgesia - whilst a well-working epidural offers excellent analgesia, the risks of postoperative hypotension, fluid overload and impaired mobility alongside reportedly high failure rates and risk of complications (such as nerve injury and epidural haematoma) has seen a move towards the use of alternative techniques.” Go to annotation (Patel et al., 2022, p. 3)
“intrathecal morphine - spinal anaesthesia has a lower failure rate compared with TEA, and is often simpler and quicker to perform.15 A systematic review of 11 trials comparing ITM with other modes of analgesia in patients undergoing open hepatic surgery demonstrated equivalent or lower pain scores with ITM. Compared with TEA, ITM reduced requirements for fluids and hospital stay. There was no difference in the rate of major complications.” Go to annotation (Patel et al., 2022, p. 3)
“continuous wound infusion - CWI catheters are an opioid-sparing alternative to TEA and may be used in conjunction with other techniques (e.g. ITM). They may be sited subcutaneously, subfascially or preperitoneally and there is debate over the optimal placement. A recent meta-analysis showed preperitoneal catheters provided superior pain relief compared with subcutaneous catheters. Evidence comparing CWI catheters with TEA in open hepatic resection is conflicting, although current guidelines state that when all aspects of postoperative care are optimised, CWI catheters in conjunction with a multimodal analgesic regimen offers a clinically acceptable alternative to TEA.” Go to annotation (Patel et al., 2022, p. 3)
“trunk blocks - there is growing interest in the use of transversus abdominal plane (TAP) blocks and erector spinae blocks as alternatives to TEA, although more clinical evidence is needed. In living donor liver resection, TAP blocks are associated with less opioid consumption, lower pain scores and shorter length of stay (LOS).” Go to annotation (Patel et al., 2022, p. 3)
“During parenchymal resection with hepatic inflow occlusion, the main source of bleeding is backflow from the valveless hepatic veins. Control of central and thus hepatic venous pressure is crucial to reduce blood loss, with the aim of achieving a near ‘bloodless’ field. Various strategies aimed at decreasing central venous pressure (CVP) have been used including diuretics (furosemidedalso a venodilator); vasodilator infusions (glyceryl trinitrate); opioid infusions (remifentanil); placing the patient in the Trendelenburg position; avoidance of PEEP (positive end-expiratory pressure); and fluid restriction until the parenchymal resection is complete.” (Patel et al., 2022, p. 4)
“Previous studies have demonstrated that CVP >5 cmH2O significantly increases bleeding and although maintenance of low CVP (<5cmH2O) intraoperatively is a well-practiced technique, its effectiveness and safety remain under scrutiny.18 A low CVP may lead to cardiovascular instability, intraoperative hypovolaemia and reduced renal and hepatosplanchnic blood flow. Supplementary vasoconstrictor drugs are often required to maintain systemic perfusion pressure of other organs. Despite concerns over vasoconstrictor-associated splanchnic hypoperfusion causing secondary hepatic ischaemia, there is no evidence to support this, nor is there definitive evidence demonstrating a link between low CVP anaesthesia and renal insufficiency. A meta-analysis of low CVP anaesthesia in hepatic resection demonstrated a reduction in blood loss and transfusion requirements but no improvement in clinical outcomes.19 Conversely a retrospective analysis of 135 hepatic resections found the use of CVP monitoring had no effect on intraoperative blood loss.20 In minimally invasive surgery monitoring CVP is complicated by transmitted pressure from the pneumoperitoneum making targeted low CVP anaesthesia less applicable.” Go to annotation (Patel et al., 2022, p. 4)
“significant blood loss can go unnoticed during CUSA usage as the suction is at the point of resection, and accumulates in separate canisters from the standard suction devices, often hidden under drapes.” Go to annotation (Patel et al., 2022, p. 4)
“Various hepatic vascular occlusion techniques have been used to reduce blood loss during surgical dissection. These include temporary hepatic inflow occlusion (Pringle manoeuvre) or inflow and outflow occlusion such as total vascular exclusion (TVE). These techniques are designed to isolate hepatic circulation (inflow, outflow, or both) from the systemic circulation, thereby reducing blood loss during dissection and transection of the hepatic parenchyma.” Go to annotation (Patel et al., 2022, p. 4)
“The Pringle manoeuvre is an example of an inflow occlusion method that involves clamping the hepatoduodenal ligament to interrupt blood flow in both the hepatic artery and portal vein. The subsequent decrease in venous return and increase in ../../Knowledge/Medicine/systemic vascular resistance may result in significant haemodynamic instability, and good communication between the surgeon and anaesthetist is essential during cases where it is being used. Prolonged continuous interruption of hepatic inflow (>1 h in normal liver or >30 min in pathological liver) may cause an ischaemia/reperfusion injury meaning occlusion is usually performed intermittently, allowing for 10-20 min of interrupted liver blood flow followed by a 5-min period of reperfusion. This protects the liver by limiting the total ischaemic time and inducing ischaemic preconditioning.” Go to annotation (Patel et al., 2022, p. 4)