Risk factors and prediction of acute kidney injury after liver transplantation: Logistic regression and artificial neural network approaches

BACKGROUND

Acute kidney injury (AKI) has serious consequences on the prognosis of patients undergoing liver transplantation. Recently, artificial neural network (ANN) was reported to have better predictive ability than the classical logistic regression (LR) for this postoperative outcome.

AIM

To identify the risk factors of AKI after deceased-donor liver transplantation (DDLT) and compare the prediction performance of ANN with that of LR for this complication.

METHODS

Adult patients with no evidence of end-stage kidney dysfunction (KD) who underwent the first DDLT according to model for end-stage liver disease (MELD) score allocation system was evaluated. AKI was defined according to the International Club of Ascites criteria, and potential predictors of postoperative AKI were identified by LR. The prediction performance of both ANN and LR was tested.

RESULTS

The incidence of AKI was 60.6% (n = 88/145) and the following predictors were identified by LR: MELD score > 25 (odds ratio [OR] = 1.999), preoperative kidney dysfunction (OR = 1.279), extended criteria donors (OR = 1.191), intraoperative arterial hypotension (OR = 1.935), intraoperative massive blood transfusion (MBT) (OR = 1.830), and postoperative serum lactate (SL) (OR = 2.001). The area under the receiver-operating characteristic curve was best for ANN (0.81, 95% confidence interval [CI]: 0.75-0.83) than for LR (0.71, 95%CI: 0.67-0.76). The root-mean-square error and mean absolute error in the ANN model were 0.47 and 0.38, respectively.

CONCLUSION

The severity of liver disease, pre-existing kidney dysfunction, marginal grafts, hemodynamic instability, MBT, and SL are predictors of postoperative AKI, and ANN has better prediction performance than LR in this scenario.

Liver transplantation: survival and indexes of donor-recipient matching

OBJECTIVE

The aim of this study was to determine the prospective capacity and impact of donor risk index, preallocation survival outcomes following liver transplant, donor model for end-stage liver disease, and balance of risk on patients' 30-day survival after liver transplantation.

METHODS

We prospectively analyzed patient survival in a multicentric observational cohort of adult liver transplantation through the year of 2019 at the state of Paraná, Brazil. The receiver operating characteristic curve, the area under the curve, and the best cutoff point (i.e., the Youden's index) were estimated to analyze the prognostic value of each index.

RESULTS

In total, 252 liver transplants were included with an average model for end-stage liver disease score of 21.17 and a 30-day survival of 79.76%. The donor risk index was the only prognostic variable with no relation to patients' 30-day mortality model for end-stage liver disease and donor model for end-stage liver disease have no prognostic value on receiver operating characteristic curve, but preallocation survival outcomes following liver transplant, survival outcomes following liver transplant, and balance of risk presented good relationship with this observation. The cutoff value was estimated in 11-12 points for balance of risk and 9-12 for preallocation survival outcomes following liver transplant and survival outcomes following liver transplant. The 30-day survival for the group of transplants with scores up to 12 points (n=172) in all the three indexes was 87.79%, and for those transplants with scores higher than 12 it was 36.36%.

CONCLUSIONS

The 30-day survival is 79.76%, and balance of risk, survival outcomes following liver transplant, and preallocation survival outcomes following liver transplant are the good prognostic indexes. The cutoff value of 12 points has clinical usefulness to predict the post-liver transplantation results.

Risk factors for acute kidney injury after partial hepatectomy

AIM

To identify risk factors for the occurrence of acute kidney injury (AKI) in the postoperative period of partial hepatectomies.

METHODS

Retrospective analysis of 446 consecutive resections in 405 patients, analyzing clinical characteristics, preoperative laboratory data, intraoperative data, and postoperative laboratory data and clinical evolution. Adopting the International Club of Ascites criteria for the definition of AKI, potential predictors of AKI by logistic regression were identified.

RESULTS

Of the total 446 partial liver resections, postoperative AKI occurred in 80 cases (17.9%). Identified predictors of AKI were: Non-dialytic chronic kidney injury (CKI), biliary obstruction, the Model for End-Stage Liver Disease (MELD) score, the extent of hepatic resection, the occurrence of intraoperative hemodynamic instability, post-hepatectomy haemorrhage, and postoperative sepsis.

CONCLUSION

The MELD score, the presence of non-dialytic CKI and biliary obstruction in the preoperative period, and perioperative hemodynamics instability, bleeding, and sepsis are risk factors for the occurrence of AKI in patients that underwent partial hepatectomy.

Acute renal injury after partial hepatectomy

Currently, partial hepatectomy is the treatment of choice for a wide variety of liver and biliary conditions. Among the possible complications of partial hepatectomy, acute kidney injury (AKI) should be considered as an important cause of increased morbidity and postoperative mortality. Difficulties in the data analysis related to postoperative AKI after liver resections are mainly due to the multiplicity of factors to be considered in the surgical patients, moreover, there is no consensus of the exact definition of AKI after liver resection in the literature, which hampers comparison and analysis of the scarce data published on the subject. Despite this multiplicity of risk factors for postoperative AKI after partial hepatectomy, there are main factors that clearly contribute to its occurrence. First factor relates to large blood losses with renal hypoperfusion during the operation, second factor relates to the occurrence of post-hepatectomy liver failure with consequent distributive circulatory changes and hepatorenal syndrome. Eventually, patients can have more than one factor contributing to post-operative AKI, and frequently these combinations of acute insults can be aggravated by sepsis or exposure to nephrotoxic drugs.

Predictors of recurrence after a first hepatectomy for colorectal cancer liver metastases: a retrospective analysis

Background

Surgical resection is considered the standard therapy in the treatment of liver metastases from colorectal cancer (CRCLM); however, most patients experience tumor recurrence after curative hepatic resection. The objective was to determine potential prognostic factors for tumor recurrence after an initial hepatectomy for CRCLM.

Methods

A study population of 101 patients who had undergone a first curative hepatectomy for CRCLM was retrospectively analyzed. Selected biological tumor markers, and clinical and pathological features were then tested by Cox regression.

Results

Synchronous liver metastases occurred in 38 patients (37.6%) and 63 patients (62.3%) presented with metachronous liver metastases. In a median follow-up time of 68 months, recurrence was observed in 64 patients (63.3%). The 5-year cumulative risk of recurrence was 56.7%. The median survival after recurrence was 24.5 months (range 1 to 41 months) and 5-year cumulative overall survival was 31.8%. Of all variables tested by Cox regression, intra- and extrahepatic resectable disease, CEA levels ≥50 ng/mL and bilobar liver disease remained significant as predictors of recurrence in the multivariate analysis.

Conclusions

Independent risk factors for recurrence after an initial hepatectomy for CRCLM, such as intra- and extrahepatic resectable disease, CEA levels ≥50 ng/mL and bilobar liver disease, can eventually help in making decisions in this very complex scenario.

Morbidity after conventional dissection of axillary lymph nodes in breast cancer patients

Background

Conventional axillary lymph node dissection (ALND) has recently become less radical. The treatment morbidity effects of reduced ALND aggressiveness are unknown. This article investigates the prevalence of the main complications of ALND: lymphedema, range-of-motion restriction, and arm paresthesia and pain.

Methods

This cross-sectional study included 200 women with invasive breast cancer who underwent breast-conserving surgery (82.5%, n = 165) or mastectomy (17.5%, n = 35) with ALND from 2007 to 2011. Arm perimetry was used to assess lymphedema, defined as a difference >2 cm in the upper arm circumference between the nonsurgical and surgical arms. Range-of-motion restriction was assessed by evaluating the degree of arm abduction. Paresthesia was measured in the inner and proximal arm regions. Arm pain was assessed by directly questioning the patients and defined as either present or absent.

Results

The average (±SD) time between ALND and morbidity evaluation was 35 ± 18 months (range, 7-60 months). The average dissected lymph node number per patient was 14 ± 4 (range, 6-30 lymph nodes). Only 3.5% (n = 7) of the patients presented with lymphedema. Single-incision approaches to breast tumor and ALND (P = 0.04) and the presence of a postoperative seroma (P = 0.02) were associated with lymphedema in univariate analysis. Paresthesia was the most frequent side effect observed (53% of patients, n = 106). This complication was associated with increased age (P < 0.0001) and a larger dissected lymph node number (P = 0.01) in univariate and multivariate analysis. Additionally, 24% (n = 48) of patients had noticeable limited arm abduction. Among the patients, 27.5% (n = 55) experienced sporadic arm pain corresponding to the surgically treated armpit. In multivariate analysis, the pain risk was 1.9-fold higher in patients who underwent ALND corresponding to their dominant arm (95% CI, 1.0-3.7, P = 0.04).

Conclusion

Conventional ALND in breast cancer patients can result in unwanted complications. However, the current lymphedema prevalence is lower than that of the other analyzed side effects.

Recurrence after liver transplantation for hepatocellular carcinoma according to up-to-seven criteria

BACKGROUND/AIMS

The Up7 criteria for HCC have recently emerged to identify potential candidates for OLT. The aim of this study was to assess the validity of the Up7 criteria according to the pathological analysis of the explanted livers.

METHODOLOGY

For recurrence risk calculation 669 HCC transplanted patients were classified according to both the pathological Milan and Up7 criteria. In order to identify potential predictors of recurrence, selected biological tumor markers and morphological features were then tested by Cox regression.

RESULTS

The 5-year HCC recurrence rate for the Milan out/Up7 in subgroup (n=87), was significantly higher than patients meeting Milan criteria (n=299), 15.8% vs. 9.4% (p=0.0290). For patients within the Up7 criteria (n=383), only pre-OLT AFP level >1000ng/mL and microvascular invasion were significant predictors for recurrence, and for those beyond the Up7 criteria (n=286), pre-OLT AFP level >1000ng/mL, poor differentiation grade and microvascular invasion remained significant.

CONCLUSIONS

Compared to the current Milan staging system, HCC patients within the pathological Up7 criteria were associated with a higher, but acceptable risk of recurrence after OLT, and along with tumor burden, other parameters can potentially be used for further refinement of HCC staging, such as AFP levels and microvascular invasion.

A randomized controlled trial comparing fibrin glue and PlasmaJet on the raw surface of the liver after hepatic resection

BACKGROUND/AIMS

In order to reduce the rate of bleeding and bile leakage after hepatic resection, different operative techniques have been used such as selective suture, electrocautery, topical hemostatic agents, argon beam coagulation, omentoplasty and application of fibrin glue.

METHODOLOGY

The PlasmaJet, a recent tool that provides a high energy flow of ionized gas which seals small blood and lymph vessels has been recently introduced into clinical practice. We have conducted a randomized trial comparing the application of 5mL of fibrin glue (Tissucol) and the treatment by PlasmaJet (Plasma Surgical Limited, Theale, UK) on the raw surface of the liver stump after elective hepatic resection.

RESULTS

Fifty-eight consecutive hepatic resections were performed and the postoperative mortality, blood transfusions and reoperations were not statistically different between the groups. However, there was a significant reduction of the incidence of collections requiring percutaneous drainage in the PlasmaJet group (p<0.001).

CONCLUSIONS

Compared to fibrin glue application, the employment of PlasmaJet on the raw surface of the liver stump led to a significant reduction of postoperative complications requiring percutaneous drainage after elective hepatectomy.

[Oncosurgical strategies for metastatic liver cancer]

Patients with liver metastases from colorectal cancer (CRC) present a major public health challenge with approximately, 1,2 million cases of CRC occur yearly worldwide. Resection of colorectal liver metastases (CRLM) is the only treatment offering the possibility of cure and has been shown to provide clear survival benefits. However, only 10 to 20% of patients with CRLM are eligible for this procedure upfront. During the last decade, major advances in the management of CRLM have taken place involving three fields: oncology, interventional radiology, and surgery. These advances have increased the resectability rate to 20-30% of cases with a 5-year survival of 35-50%. Neoadjuvant treatment with chemotherapeutic agents such as irinotecan and oxaliplatin, and hepatic artery infusion combined with systemic therapy and biologic agents (bevacizumab, cetuximab) play an important role in increasing the number of patients eligible to secondary resection. However, with the progressive use of neoadjuvant chemotherapy further studies are necessary to answer questions such as the risk: benefit ratio in maximizing response rates versus vascular changes in the liver (current opinion still divided concerning their importance). These questions remain challenging and should not be underestimated. In this review, we have described the current oncosurgical strategies employed in patients with resectable and non resectable CRLM, their benefits, and future treatment strategies.

Esofagogastrectomia com linfadenectomia em dois campos no câncer do esôfago torácico

OBJETIVO: Avaliar as indicações, sobrevida e fatores prognósticos da esofagogastrectomia com linfadenectomia em dois campos no câncer do esôfago torácico. MÉTODOS: Foram avaliados 111 pacientes retrospectivamente no período de janeiro de 1990 a dezembro de 2001 sendo 83 homens e 29 mulheres. A idade média dos pacientes foi 55,1 anos (variando entre 35-79). A linfadenectomia em dois campos foi parcial (Standard) em 34 pacientes(30,6%) e ampliada em 77(69,4%). RESULTADOS: A média de linfonodos dissecados foi de 22,6(variando entre 4 e 50). A doença R0 ocorreu em 53 pacientes(47,7%) a doença residual microscópica (R1) em 57 (52,3%) e a doença residual R2 em um paciente(0,9%). A recidiva ocorreu em 32 pacientes (28,8%) sendo em sete (6,3%) cervical, 17 (15,3%) locorregional e 19 (17,1%) sistêmica. A morbidade e mortalidade pós-operatória foram de 31,5% e 9% respectivamente, sem diferença significativa em relação á extensão da linfadenectomia mediastinal. A sobrevida global dos 111 pacientes em cinco anos foi de 48,4%, sem diferença significativa na sobrevida em relação á extensão da linfadenectomia, porém, houve aumento significativo na sobrevida livre de doença a favor dos paciente submetidos a linfadenectomia mediastinal ampliada(p=0,01). A ausência de doença residual (R0), comprometimento linfonodal (pN0) e o número de linfonodos comprometidos inferior a quatro, indicaram bom prognóstico. CONCLUSÃO: A esofagogastrectomia com linfadenectomia em dois campos apresentou um impacto positivo na taxa de sobrevida em cinco anos nos pacientes com câncer do esôfago torácico, particularmente em relação aos pacientes com ECIII. A linfadenectomia mediastinal ampliada aumentou significativamente a sobrevida livre de doença.