Impact of abdominal drainage systems on postoperative complication rates following liver transplantation

Consensus document from the Spanish Society for Liver Transplantation: Enhanced recovery after liver transplantation

The goal of the Spanish Society for Liver Transplantation (Sociedad Española de Trasplante Hepático) is to promote and create consensus documents about current topics in liver transplantation with a multidisciplinary approach. To this end, in November 2022, the 10th Consensus Document Meeting was held, with the participation of experts from the 26 authorized Spanish liver transplantation programs. This edition discusses enhanced recovery after liver transplantation, dividing needed actions into 3periods: preoperative, intraoperative and postoperative. The evaluated evidence and the consensus conclusions for each of these topics are described.

Consensus document from the Spanish Society for Liver Transplantation: enhanced recovery after liver transplantation

The goal of the Spanish Society for Liver Transplantation (La Sociedad Española de Trasplante Hepático) is to promote and create consensus documents about current topics in liver transplantation with a multidisciplinary approach. To this end, in November 2022, the 10th Consensus Document Meeting was held, with the participation of experts from the 26 authorized Spanish liver transplantation programs. This edition discusses Enhanced Recovery After Liver Transplantation, dividing needed actions into three periods: preoperative, intraoperative and postoperative. The evaluated evidence and the consensus conclusions for each of these topics are described.

Active Intra-Abdominal Drainage Following Abdominal Digestive System Surgery: A Meta-Analysis and Systematic Review

BACKGROUND

Our objective is to compare the early outcomes associated with passive (gravity) drainage (PG) and active drainage (AD) after surgery.

METHODS

Studies published until April 28, 2022 were retrieved from the PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, Web of Science databases.

RESULTS

Nine studies with 14,169 patients were identified. Two groups had the same intra-abdominal infection rate (RR: 0.55; P = 0.13); In subgroup analysis of pancreaticoduodenectomy, active drainage had no significant effect on postoperative pancreatic fistula (POPF) rate (RR: 1.21; P = 0.26) and clinically relevant POPF (CR-POPF) (RR: 1.05; P = 0.72); Active drainage was not associated with lower percutaneous drainage rate (RR: 1.00; P = 0.96), incidence of sepsis (RR: 1.00; P = 0.99) and overall morbidity (RR: 1.02; P = 0.73). Both groups had the same POPF rate (RR: 1.20; P = 0.18) and CR-POPF rate (RR: 1.20; P = 0.18) after distal pancreatectomy. There was no difference between two groups on the day of drain removal after pancreaticoduodenectomy (Mean difference: -0.16; P = 0.81) and liver surgery (Mean difference: 0.03; P = 0.99).

CONCLUSIONS

Active drainage is not superior to passive drainage and both drainage methods can be considered.

Ultrastructural Analysis of Volumetric Histotripsy Bio-effects in Large Human Hematomas

Large-volume soft tissue hematomas are a serious clinical problem, which, if untreated, can have severe consequences. Current treatments are associated with significant pain and discomfort. It has been reported that in an in vitro bovine hematoma model, pulsed high-intensity focused ultrasound (HIFU) ablation, termed histotripsy, can be used to rapidly and non-invasively liquefy the hematoma through localized bubble activity, enabling fine-needle aspiration. The goals of this study were to evaluate the efficiency and speed of volumetric histotripsy liquefaction using a large in vitro human hematoma model. Large human hematoma phantoms (85 cc) were formed by recalcifying blood anticoagulated with citrate phosphate dextrose/saline-adenine-glucose-mannitol solution. Typical boiling histotripsy pulses (10 or 2 ms) or hybrid histotripsy pulses using higher-amplitude and shorter pulses (0.4 ms) were delivered at 1% duty cycle while continuously translating the HIFU focus location. Histotripsy exposures were performed under ultrasound guidance with a 1.5-MHz transducer (8-cm aperture, F# = 0.75). The volume of liquefied lesions was determined by ultrasound imaging and gross inspection. Untreated hematoma samples and samples of the liquefied lesions aspirated using a fine needle were analyzed cytologically and ultrastructurally with scanning electron microscopy. All exposures resulted in uniform liquid-filled voids with sharp edges; liquefaction speed was higher for exposures with shorter pulses and higher shock amplitudes at the focus (up to 0.32, 0.68 and 2.62 mL/min for 10-, 2- and 0.4-ms pulses, respectively). Cytological and ultrastructural observations revealed completely homogenized blood cells and fibrin fragments in the lysate. Most of the fibrin fragments were less than 20 μm in length, but a number of fragments were up to 150 μm. The lysate with residual debris of that size would potentially be amenable to fine-needle aspiration without risk for needle clogging in clinical implementation.

Practical model to identify liver transplant recipients at low risk of postoperative haemorrhage, bile leakage and ascites

Background

This study aimed to identify a subgroup of recipients at low risk of haemorrhage, bile leakage and ascites following liver transplantation (LT).

Methods

Factors associated with significant postoperative ascites (more than 10 ml/kg on postoperative day 5), bile leakage and haemorrhage after LT were identified using three separate multivariable analyses in patients who had LT in 2010–2019. A model predicting the absence of all three outcomes was created and validated internally using bootstrap procedure.

Results

Overall, 944 recipients underwent LT. Rates of ascites, bile leakage and haemorrhage were 34.9, 7.7 and 6.0 per cent respectively. The 90-day mortality rate was 7.0 per cent. Partial liver graft (relative risk (RR) 1.31; P = 0.021), intraoperative ascites (more than 10 ml/kg suctioned after laparotomy) (RR 2.05; P = 0.001), malnutrition (RR 1.27; P = 0.006), portal vein thrombosis (RR 1.56; P = 0.024) and intraoperative blood loss greater than 1000 ml (RR 1.39; P = 0.003) were independently associated with postoperative ascites and/or bile leak and/or haemorrhage, and were introduced in the model. The model was well calibrated and predicted the absence of all three outcomes with an area under the curve of 0.76 (P = 0.001). Of the 944 patients, 218 (23.1 per cent) fulfilled the five criteria of the model, and 9.6 per cent experienced postoperative ascites (RR 0.22; P = 0.001), 1.8 per cent haemorrhage (RR 0.21; P = 0.033), 4.1 per cent bile leak (RR 0.54; P = 0.048), 40.4 per cent severe complications (RR 0.70; P = 0.001) and 1.4 per cent 90-day mortality (RR 0.13; P = 0.004).

Conclusion

A practical model has been provided to identify patients at low risk of ascites, bile leakage and haemorrhage after LT; these patients could potentially qualify for inclusion in non-abdominal drainage protocols.

Cytokine Expression Pattern and Protein-Protein interaction network analysis of Leucocyte Rich Platelet Rich Fibrin and Injectable Form of Platelet Rich Fibrin

PURPOSE

Platelet-rich fibrin (PRF) such as leucocyte-rich PRF (L-PRF) and injectable form of PRF (i-PRF) are widely used in various surgical applications. L-PRF- and i-PRF-derived cytokine variations and functional pathways are still unexplored. The aim of the study was to evaluate the expression pattern of Th1-, Th2-, and Th17-related cytokines by L-PRF and i-PRF under in vitro.

METHODS

Cytokine levels were evaluated using multi-analyte ELISArray kit. Using elevated level of cytokines, the protein-protein interaction and pathway were predicted by computational method.

RESULTS

The expressed cytokine levels were higher in L-PRF than in i-PRF. Specifically in L-PRF, IL8, IL2, IL6, and IL1A were expressed abundantly, whereas IL4, IL10, and IL6 were significantly high in i-PRF. Furthermore, protein-protein interaction (PPI) networks (cytokine-cytokine interactions) and pathway analyses were predicted using higher-order cytokines. PPI networks and gene ontology enrichment analysis showed functional variations between L-PRF and i-PRF. Kyoto Encyclopedia of Gene and Genome pathway analysis found that L-PRF mediates NF-k B signaling, Toll-like receptor signaling (TLR), and MAPK signaling via T-cell receptor signaling pathway. i-PRF is significantly involved in JAK-STAT signaling pathway through upregulation of STAT1.

CONCLUSION

Our study concludes that L-PRF and i-PRF act via different pathways that confirm functional variations between them. Therefore, we speculate that L-PRF may be effective in acute phase of chronic wounds such as in diabetes mellitus and immunocompromised patients whereas i-PRF may have a better outcome in acute wounds.

Effect of Stiffness of Large Extravascular Hematomas on Their Susceptibility to Boiling Histotripsy Liquefaction in Vitro

Large intra-abdominal, retroperitoneal and intramuscular hematomas are common consequences of sharp and blunt trauma and post-surgical bleeds, and often threaten organ failure, compartment syndrome or spontaneous infection. Current therapy options include surgical evacuation and placement of indwelling drains that are not effective because of the viscosity of the organized hematoma. We have previously reported the feasibility of using boiling histotripsy (BH)-a pulsed high-intensity focused ultrasound method-for liquefaction of large volumes of freshly coagulated blood and subsequent fine-needle aspiration. The goal of this work was to evaluate the changes in stiffness of large coagulated blood volumes with aging and retraction in vitro, and to correlate these changes with the size of the BH void and, therefore, the susceptibility of the material to BH liquefaction. Large-volume (55-200 mL) whole-blood clots were fabricated in plastic molds from human and bovine blood, either by natural clotting or by recalcification of anticoagulated blood, with or without addition of thrombin. Retraction of the clots was achieved by incubation for 3 h, 3 d or 8 d. The shear modulus of the samples was measured with a custom-built indentometer and shear wave elasticity (SWE) imaging. Sizes of single liquefied lesions produced with a 1.5-MHz high-intensity focused ultrasound transducer within a 30-s standard BH exposure served as the metric for susceptibility of clot material to this treatment. Neither the shear moduli of naturally clotted human samples (0.52 ± 0.08 kPa), nor their degree of retraction (ratio of expelled fluid to original volume 50%-58%) depended on the length of incubation within 0-8 d, and were significantly lower than those of bovine samples (2.85 ± 0.17 kPa, retraction 5%-38%). In clots made from anticoagulated bovine blood, the variation of calcium chloride concentration within 5-40 mmol/L did not change the stiffness, whereas lower concentrations and the addition of thrombin resulted in significantly softer clots, similar to naturally clotted human samples. Within the achievable shear modulus range (0.4-1.6 kPa), the width of the BH-liquefied lesion was more affected by the changes in stiffness than the length of the lesion. In all cases, however, the lesions were larger compared with any soft tissue liquefied with the same BH parameters, indicating higher susceptibility of hematomas to BH damage. These results suggest that clotted bovine blood with added thrombin is an acceptable in vitro model of both acute and chronic human hematomas for assessing the efficiency of BH liquefaction strategies.

Technical Aspects of Orthotopic Liver Transplantation-a Survey-Based Study Within the Eurotransplant, Swisstransplant, Scandiatransplant, and British Transplantation Society Networks

BACKGROUND

Orthotopic liver transplantation (OLT) has emerged as the mainstay of treatment for end-stage liver disease. However, technical aspects of OLT are still subject of ongoing debate and are widely based on personal experience and local institutional protocols.

METHODS

An international online survey was sent out to all liver transplant centers (n = 52) within the Eurotransplant, Swisstransplant, Scandiatransplant, and British Transplant Society networks. The survey sought information on center-specific OLT caseload, vascular and biliary reconstruction, graft reperfusion, intraoperative control of hemodynamics, and drain policies.

RESULTS

Forty-two centers gave a valid response (81%). Out of these, 50% reported piggy-back and 40.5% total caval replacement as their standard technique. While 48% of all centers generally do not apply veno-venous bypass (vvBP) or temporary portocaval shunt (PCS) during OLT, vvBP/PCS are routinely used in six centers (14%). Portal vein first reperfusion is used in 64%, followed by simultaneous (17%), and retrograde reperfusion (12%). End-to-end duct-to-duct anastomosis without biliary drain (67%) is the most frequently performed method of biliary reconstruction. No significant associations were found between the center caseload and the surgical approach used. The predominant part of the centers (88%) stated that techniques of OLT are not evidence-based and 98% would participate in multicenter clinical trials on these topics.

CONCLUSION

Technical aspects of OLT vary widely among European centers. The extent to which center-specific variation of techniques affect transplant outcomes in Europe should be elucidated further in prospective multicenter trials.