Guillain-Barré syndrome after orthotopic liver transplantation: A clinical manifestation of immune reconstitution inflammatory syndrome?

2018

Guillain-Barrè Syndrome, as part of the spectrum of dysimmune neuropathies, is unexpected to occur in immunocompromised hosts. We describe a clinical case of Guillain-Barrè syndrome, occurred a few weeks after a liver transplant, and we postulate that our case would satisfy all requirements to explain this peripheral nervous system complication as a clinical manifestation of an Immune reconstitution inflammatory syndrome. In this setting of liver transplantation, complicated by potentially multiple infective triggers, reduction of immunosuppression and reversal of pathogen-induced immunosuppression, through antimicrobial therapy, may have led to pro-inflammatory response. The pro-inflammato…

Clinical and Molecular-Based Approach in the Evaluation of Hepatocellular Carcinoma Recurrence after Radical Liver Resection

2021

Background: Hepatic resection remains the treatment of choice for patients with early-stage HCC with preserved liver function. Unfortunately, however, the majority of patients develop tumor recurrence. While several clinical factors were found to be associated with tumor recurrence, HCC pathogenesis is a complex process of accumulation of somatic genomic alterations, which leads to a huge molecular heterogeneity that has not been completely understood. The aim of this study is to complement potentially predictive clinical and pathological factors with next-generation sequencing genomic profiling and loss of heterozygosity analysis. Methods: 124 HCC patients, who underwent a primary hepatic …

Significance of the effective remnant liver volume in major hepatectomies

2005

The aim of this study is to identify the minimum safe amount of effective remnant liver volume (ERLV) in patients undergoing a major hepatectomy. Thirty-eight consecutive major hepatectomies (resection of ≥3 Couinaud segments) performed between July 1999 and March 2004 in which a frozen section liver biopsy was obtained were included. No patient had chronic viral hepatitis, cirrhosis, or cholestasis. The total liver volume (TLV) was calculated using the Vauthey formula, and the postsurgical liver volume (PSLV) was derived by subtracting the estimated volume of liver resected from the TLV. The PSLV minus the percentage of macrovesicular steatosis as nonfunctional liver was defined as the ef…

Liver Transplantation for Unresectable Intrahepatic Cholangiocarcinoma: The Role of Sequencing Genetic Profiling

2021

Simple Summary Intrahepatic cholangiocarcinoma is a rare disease with increasing incidence and mortality still characterized by an insufficient clinical outcome. Growing attention has recently surrounded this disease, and liver transplantation has emerged as a novel curative treatment for cholangiocarcinoma, along with a better understanding of genetic alterations potentially capable of driving tumorigenesis. The aim of this paper is to present a clinical description of our case series of patients affected by intrahepatic cholangiocarcinoma and by mixed forms of hepatocellular and cholangiocellular carcinoma, together with a genomic profiling of mutations occurring in a panel of genes relev…

Impact of Italian Score for Organ Allocation System on Deceased Donor Liver Transplantation: A Monocentric Competing Risk Time-to-Event Analysis

2019

Background: Liver transplantation (LT) is the only definitive and curative treatment for patients with end-stage liver disease and hepatocellular carcinoma. We aimed to evaluate the impact of the Italian score for organ allocation (ISO) in terms of the waiting-list mortality, probability of LT, and patient survival after LT. Patient and methods: All of the adult patients on the waiting list for LT at our institute from January 2014 to December 2017 were included in the study. The probabilities of death while on the waiting list, dropout from the list, and LT were compared by means of cumulative incidence functions, in a competing risk time-to-event analysis setting. Uni- and multivariable l…

Complications in Immunosuppressive Therapy of Liver Transplant Recipients

2011

BACKGROUND: In liver transplantation (LT), modern immunosuppressive protocol is focused on early corticosteroid (CS) weaning. The aim of the study was to investigate all early transplant-related complications using Clavien grading system, in order to identify a significant relation in two homogenous groups of consecutive liver transplanted patients, only different for steroid avoidance in immunosuppressive regimen. MATERIALS AND METHODS: One group was treated with a tacrolimus-based CS-free immunosuppressive protocol, the other one underwent tacrolimus plus low dose CS therapy. The preoperative continuous variables analyzed were age, gender, model for end-stage liver disease (MELD) score, a…

Laparoscopic Microwave Thermal Ablation for the Treatment of Hepatocellular Carcinoma in Chronic Hepatic Patients

2020

Background: Laparoscopic microwave thermal ablation (LMWTA) is a well-established alternative treatment to liver resection for treatment of liver tumors. The aim of this study was to describe our experience in LMWTA for hepatocellular carcinoma (HCC) in chronic hepatic patients. Materials and Methods: A study group of 61 consecutive HCC patients treated with LMWTA from January, 2013 to May, 2020 were considered for this study. Patient characteristics, liver function test, operational characteristics, and complications were recorded. Results: Of the 61 patients who underwent LMWTA, median age was 64 (interquartile range [IQR]: 58-71) years, mean body mass index was 26.2 (IQR: 23.2-29.4); 44 …

Selective decontamination of the digestive tract in adult-to-adult living related liver transplant patients: a single centre experience

2008

Adult to Adult Living Donor Liver Transplantation in Recipients with Low MELD: A Strategy Intended to Overcome Donor Shortage

2020

Recent series have demonstrated advantages of living donor over deceased donor liver transplantation, with particular benefit for those with low model for end-stage liver disease score. The logic underlying the transplantation of patients before they become too sick is intuitive. It reduces mortality and drop outs from the waiting list and makes transplant surgery less demanding. Those principles have to be balanced with donor safety and transplant benefit for the recipient avoiding early, futile transplantation. The authors report a case of adult to adult right lobe living donor liver transplantation performed for a recipient affected by primary biliary cirrhosis with MELD score of 15, in …

Neurological Screening in Elderly Liver Transplantation Candidates: A Single Center Experience.

2022

Background: Cerebral small vessels disease (cSVD) is an age-related disorder and risk factor for stroke and cognitive/motor impairments. Neurological complications (NCs) are among the causes of adverse outcomes in older liver transplant recipients. This study sought to determine whether cSVD predicts acute NCs in over 65-year-old liver transplant patients. Methods: Data were collected, from a retrospective medical chart review, of 22 deceased donor liver transplant recipients aged 65 years or older with a pre-operative brain magnetic resonance imaging (MRI). We used the Fazekas score (0–3) as a quantitative measurement of the vascular lesion load seen in the MRI. We analyzed all post-operat…

Acute and reversible Pisa syndrome as unusual presentation of portosystemic encephalopathy

2020

Abstract We present the first case of acute and reversible Pisa Syndrome, as a clinical manifestation of a portosystemic encephalopathy bout occurring in a patient affected with cirrhosis and clinical-radiological signs of acquired hepatocerebral degeneration, without exposure to psychotropic medications. A 62 year-old man suffering from cirrhosis was admitted to our hospital for sudden onset of mild confusion and postural change. He was observed walking and standing with a tilt toward the right during the last two hours. On neurological examination, he showed bilateral asterixis and extrapyramidal signs. Clinical diagnosis of Pisa Syndrome was made in a setting of raised serum ammonia. A b…

Left Spigelian Hernia in Super-Obese Patient: A Case-Report.

2011

Abstract: We report a case in which a giant Spigelian hernia presented with severe, persistent abdominal pain in a 62- year-old super-obese woman with a history of total abdominal hysterectomy-bilateral salpingo-oopherectomy at the age of 40 years for benign neoplasia, who later underwent open hernia repair (maximal diameter of the hernia sac: 21 cm) because of the development of compartment syndrome. Afterward, although a large incarcerated hernia disease was found, the sac removal was technically difficult and an open procedure was carried out, with double-mesh placement. No complications were recorded during the post-operative course. We report a difficult issue related to the diagnosis …

Imaging of hepatocellular carcinoma recurrence after liver transplantation

2023

Abstract Liver transplantation (LT) provides the highest survival benefit to patients with unresectable hepatocellular carcinoma (HCC). The Milan criteria have been developed for the selection of LT candidates with the goal of improving survival and maintaining an acceptable risk of HCC recurrence. Despite this, recurrence of HCC after LT occurs in up to 20% of cases and represents a major concern due to the poor prognosis of these patients. Furthermore, several extended criteria for the selection of LT candidates have been proposed to account for the growing demand for organs and the resultant increase in the risk of HCC recurrence. Radiologists should be aware that HCC can recur after LT…

Case report: Trans-papillary free stenting of the cystic duct and of the common bile duct in a double biliary ducts anastomoses of a right lobe livin…

2021

Abstract Background One of the major issues related to the living donor liver transplantation recipient outcome is still the high rate of biliary complication, especially when multiple biliary ducts are present and multiple anastomoses have to be performed. Case presentation and conclusion We report a case of adult-to-adult right lobe living donor liver transplantation performed for a recipient affected by alcohol-related cirrhosis with MELD score of 17. End-stage liver disease was complicated by refractory ascites, portal hypertension, small esophageal varices and portal gastropathy, hypersplenism, and abundant right pleural effusion. Here in the attached video we described the adult-to-ad…

Thyroid ectopia of the liver: An unusual diagnosis with contrast-enhanced EUS (with video)

2019

No abstract available

Impact of margin status on long-term results of liver resection for hepatocellular carcinoma: single-center time-to-recurrence analysis

2020

Occult metastasis from the initial tumor and a de novo second primary hepatocellular carcinoma (HCC) were recognized as the main causes for the onset of early and late HCC recurrence, after liver resection (LR). This study aims to compare the time to recurrence after LR for HCC in which a margin ≤ 1 mm or > 1 mm was achieved. A single-center retrospective study involving 256 patients was conducted from June 2005 to June 2019. HCC patients resected with a radical surgical approach were investigated and stratified into groups A (resection margins ≤ 1 mm) and B (> 1 mm), as measured on final pathologic assessment. Kaplan–Meier estimators were used to estimate the probability of recurrenc…

Impact of Extended-Criteria Donor Liver Grafts on Benchmark Metrics of Clinical Outcome After Liver Transplantation: A Single Center Experience.

2020

Abstract Background The adoption of extended criteria for donors remains the best strategy to widen the pool of available liver graft against the chronic shortage of donors. Benchmarking in liver transplantation (LT) offers the unprecedented opportunity to compare clinical outcome measures to a set of validated reference values. We aimed to evaluate the impact of marginal grafts usage in a cohort of low-risk benchmark cases from an area with a very low rate of deceased donation. Methods A cohort of low-risk benchmark cases was identified from all adult patients who underwent LT at our center. Among these patients, those transplanted with a graft from an extended-criteria donor (ECD) were id…

Importance of sarcopenia parameter changes after living donor liver transplantation

2017

The systemic role of muscle tissue is strengthened by the large system of hormones, chemokines and other mediators that constitute a dense network of communication between the skeletal muscle and the liver (1,2). This, associated with the evidence of a progressive malnutrition and depletion of muscle mass in end-stage liver disease (ESLD) patients, has led many to study the role of sarcopenia and its systemic effects in this setting, and to identify it as critical risk factor for post- liver transplantation (LT) mortality (3-5). Englesbe and colleagues found a direct correlation between central sarcopenia, measured by computerized tomography (CT), the total area of the psoas muscle (psoas a…

Are radiological endpoints surrogate outcomes of overall survival in hepatocellular carcinoma treated with transarterial chemoembolization?

2021

Background& Aims: Time to progression (TTP) and progression-free survival (PFS) are commonly used as surrogate endpoints in oncology trials. We aimed to assess the surrogacy relationship of TTP and PFS with overall survival (OS) in studies of transarterial chemoembolization (TACE) for unresectable hepatocellular carcinoma (u-HCC) by innovative methods. Methods: A search of databases for studies of TACE for u-HCC reporting both OS and TTP or PFS was performed. Individual patient data were extracted from TTP/PFS and OS Kaplan-Meier curves of TACE arms. Pooled median TTP and OS were obtained from random-effect model. The surrogate relationships of hazard ratios (HRs) and median TTP for OS …

Risk factors for bile leakage after liver resection for neoplastic disease.

2022

Biliary leakage (BL) remains the most frequent and feared complication after hepatoresective surgery. Placement of the abdominal drainage at the end of liver surgery remains controversial due to the delicate balance between risks and potential benefits in case of BL. The study was aimed to detect possible risk factors for BL occurrence after liver surgery. We enrolled all oncologic patients who underwent liver resection from June 2016 to March 2021. BL was diagnosed according to the ISGLS definition. We have examined demographic characteristics of the patients, type of neoplasia, presence of cirrhosis, neoadjuvant chemotherapy and type of intervention. Uni- and multivariable analyses were p…

Enhanced Recovery after Implementation of Surgery Protocol in Living Kidney Donors: The ISMETT Experience

2019

Abstract Introduction Laparoscopic living donor nephrectomy (LLDN) has become the standard procedure for living kidney transplantation. Enhanced recovery after surgery (ERAS) is a multimodal perioperative management aimed at facilitating rapid patient recovery after major surgery by modifying the response to stress induced by exposure to surgery. This association can further reduce hospital stay, surgical stress, and perioperative morbidity of living kidney donors. Material and methods In this retrospective analysis conducted at our institute, we compared the first 21 patients who underwent LLDN enrolled with the ERAS protocol with 55 patients who underwent LLDN with the fast-track protocol…

Comparison of two different techniques of reperfusion in adult orthotopic liver transplantation

2006

: The aim of this study was to determine the impact of two reperfusion techniques on the peri-operative hemodynamic changes and early post-operative graft function of adult patients undergoing orthotopic liver transplantation. Material and methods: From June 2003 to May 2004, 50 consecutive liver transplants were performed and divided into two groups: group A, 25 patients, portal vein flush with 500 cm3 of Ringer's lactate without vena caval venting. Group B, 25 patients, vena caval venting with no portal vein flush. Donor and recipient characteristics were similar in both groups. Sixty-four different parameters were analyzed, and Pearson's χ2 test and t-test were used for statistical analy…

Liver Perfusate Natural Killer Cells from Deceased Brain Donors and Association with Acute Cellular Rejection after Liver Transplantation: A Time-to-…

2019

Background The ability to predict which recipients will successfully complete their posttransplant clinical course, which is crucial for liver transplant (LT) programs. The assessment of natural killer (NK) cell subset determined by flow cytometry from a monocentric series of consecutive liver perfusates could help identify risk factors portending adverse LT outcomes. Methods Liver perfusates were collected during the back-table surgical time after the procurement procedures for donors after brain death. Lymphocytic concentrations and phenotypes were matched with donors after brain death characteristics and indications, timing, surgical techniques, outcomes, and biopsy-proven acute cellular…

Early Regeneration of the Remnant Liver Volume after Right Hepatectomy for Living Donation: A Multiple Regression Analysis.

2012

Early liver regeneration was studied in a series of 70 patients who underwent right hepatectomy for living donation between November 2004 and January 2010. Liver regeneration was evaluated with multidetector computed tomography (MDCT) at a mean of 61.07 days after surgery. Presurgical variables [eg, age, weight, height, body mass index (BMI), liver function tests, creatinine levels, platelet counts, international normalized ratio, and glucose levels] and variables detected with preoperative MDCT imaging [eg, main portal vein diameter, steatosis, original liver volume, and spleen volume (SV)] were investigated as potential predictors of liver regeneration. The future remnant liver volume (FR…

Use of Hepatitis C-Positive Deceased Liver Donors in Response to the Organ Shortage in an Endemic Area

2017

The region of Sicily, Italy, is witnessing a chronic organ shortage. Thus, to face this critical issue, the use of marginal donors has increased over time. An example of marginal donor expansion is the use of liver donors who are positive for the hepatitis C antibody (HCV+) for HCV+ patients requiring liver transplantation (LT). In view of new advances in HCV therapy, including direct-acting agents (DAAs) to treat HCV in the post-transplant setting, our study focused on a monocentric experience in a series of consecutive LTs performed in adult patients receiving HCV+ liver donor allografts. From 2003 to 2016 at our institute we performed 10 LT using HCV+ deceased donors. In particular, the …

Crucial Role of Extended Criteria Donors in Deceased Donor Single Kidney Transplantation to Face Chronic Shortage in the Heart of the Mediterranean B…

2019

Background: The gap between organ availability and patients on the waiting list for deceased donor kidney transplants has resulted in the wide use of extended criteria donors (ECDs).We aimed to compare the surgical outcomes of single kidney transplantation (KT) performed at our institute with standard criteria donor (SCD) or ECD grafts, according to the Organ Procurement and Transplantation Network definition. Patients and methods. Our retrospective analysis studied 115 adult recipients of KT from January 2016 to July 2018, with kidney grafts procured from adult donors after brain or circulatory death, performed at our institute. Among the 2 recipients’ groups, we compared the incidence of …

ERAS Protocol for Perioperative Care of Patients Treated with Laparoscopic Nonanatomic Liver Resection for Hepatocellular Carcinoma: The ISMETT Exper…

2020

Background: Liver resection (LR) remains the best therapeutic option for patients with early-stage hepatocellular carcinoma (HCC) with preserved hepatic function and who are not eligible for liver transplantation. After its inception, the enhanced recovery after surgery (ERAS) protocol was widely used for treating patients with liver cancer, although there are still no clear indications for improving upon it in both open and laparoscopic surgery. Objective: This study aims to describe our institute's experience in the application of the ERAS protocol in a cohort of HCC patients, and to explore possible factors that could have an impact on postoperative outcomes. Materials and Methods: We re…

Human Amnion-Derived Mesenchymal Stromal Cells: A New Potential Treatment for Carbapenem-Resistant Enterobacterales in Decompensated Cirrhosis

2022

Background: Spontaneous bacterial peritonitis (SBP) is a severe and often fatal infection in patients with decompensated cirrhosis and ascites. The only cure for SBP is antibiotic therapy, but the emerging problem of bacterial resistance requires novel therapeutic strategies. Human amniotic mesenchymal stromal cells (hA-MSCs) possess immunomodulatory and anti-inflammatory properties that can be harnessed as a therapy in such a context. Methods: An in vitro applications of hA-MSCs in ascitic fluid (AF) of cirrhotic patients, subsequently infected with carbapenem-resistant Enterobacterales, was performed. We evaluated the effects of hA-MSCs on bacterial load, innate immunity factors, and macr…

The addition of simvastatin administration to cold storage solution of explanted whole liver grafts for facing ischemia/reperfusion injury in an area…

2018

Abstract Background Liver transplantation is the best treatment for end-stage liver disease. The interruption of the blood supply to the donor liver during cold storage damages the liver, affecting how well the liver will function after transplant. The drug Simvastatin may help to protect donor livers against this damage and improve outcomes for transplant recipients. The aim of this study is to evaluate the benefits of treating the donor liver with Simvastatin compared with the standard transplant procedure. Patient and methods We propose a prospective, double-blinded, randomized phase 2 study of 2 parallel groups of eligible adult patients. We will compare 3-month, 6-month, and 12-month g…

Role of Allelic Imbalance in Predicting Hepatocellular Carcinoma (HCC) Recurrence Risk After Liver Transplant.

2019

BACKGROUND One of the most controversial problems for liver transplantation in patients affected by hepatocellular carcinoma (HCC) remains the lack of an oncologic staging system to predict cancer recurrence after liver transplantation (LT). We analyzed allelic imbalance (AI) in 19 microsatellites, and assessed the post-LT HCC recurrence risk. MATERIAL AND METHODS Seventy-one patients were included; 18 had tumor recurrence within 5 years post-transplant. Molecular analysis was done in the primary HCC and peripheral blood samples: a total of 19 microsatellites was used to assess AI. Specific AI was evaluated when outside of range value between 0.66 and 1.5. Based on data in the literature, w…

Sicily Network for Liver Cancer: A Multidisciplinary Network Model for the Management of Primary Liver Tumors

2020

Background: The management of primary liver tumors requires the involvement of multiple specialist skills and the best possible treatment in terms of cost, risk, and benefit that could be provided by hepatobiliary or transplant surgeon, interventional radiologist, hepatologist, radiotherapist, or oncologist is needed to be chosen for each patient. This is particularly relevant for hepatocellular carcinoma (HCC), that is the most common primary liver tumor, and it occurs in more than 90% of cases in the setting of cirrhosis. Methods: To address the increasing complexity of cancer care, multidisciplinary tumor boards (MDTBs) have evolved to offer patients appropriate and tailored cancer treat…

The use of normothermic machine perfusion to rescue liver allografts from expanded criteria donors

2021

The use of expanded criteria donors is one of the strategies used to overcome the gap between the demand for organs and the number of donors. Physicians debate the extent to which marginal grafts can be used. In recent years, normothermic machine perfusion (NMP) has been used to test liver viability before transplantation. Grafts underwent NMP whenever histological steatosis was > 40% or there were at least three Eurotransplant criteria for expanded criteria donor (ECD). We used NMP to test 19 grafts, 3 from donation after type 3 controlled cardiac death (DCD), and 16 from donation after brain death (DBD). Only two grafts from DBD were not transplanted, because perfusion proved they were…

Mini-Invasive Approach Contributes to Expand the Indication for Liver Resection for Hepatocellular Carcinoma Without Increasing the Incidence of Post…

2016

Liver resection (LR) for hepatocellular carcinoma (HCC) is the best alternative option for increasing the survival of many patients with intermediate or advanced stages of the Barcelona Clinic Liver Cancer staging classification. Mini-invasive approach may play a positive role in treating a tumor rising almost exclusively in a diseased liver.A prospectively collected database was retrospectively reviewed for 167 consecutive patients who underwent LR between 1999 and 2015.A total of 38 LRs were performed from 1999 to 2009 (Period I), and 129 between 2010 and 2015 (Period II). Laparoscopic procedures increased from 5.3% to 38.1%. Not undergoing laparoscopic LR increased length of stay, and Cl…

How important is the role of iterative liver direct surgery in patients with hepatocellular carcinoma for a transplant center located in an area with…

2022

IntroductionHepatocellular carcinoma (HCC) accounts for nearly 90% of primary liver cancers, with estimates of over 1 million people affected by 2025. We aimed to explore the impacting role of an iterative surgical treatment approach in a cohort of HCC patients within the Milan criteria, associated with clinical risk factors for tumor recurrence (RHCC) after liver transplant (LT) and loco-regional therapies (LRT), as well as liver resection (LR) and/or microwave thermal ablation (MWTA).MethodsWe retrospectively analyzed our experience performed during an 8-year period between January 2013 and December 2021 in patients treated for HCC, focusing on describing the impact on preoperative end-st…

Single center report on complications in steroid-free immunosuppressive therapy of liver transplant recipients

2010

Peri-Operative Liver Regeneration of the Remnant Liver Volume after Right Hepatectomy for Living Donation: A Multiple Regression Analysis

2012

Early liver regeneration was studied in a series of 70 patients who underwent right hepatectomy for living donation from November 2004 to January 2010. Liver regeneration was evaluated by multidetector computed tomography at a mean time of 61.07 days after surgery. Pre-surgical variables such as age, weight, height, body mass index, liver function tests, creatinine, platelet count, international normalized ratio, glucose, and variables detected with preoperative multidetector computed tomography imaging, including diameter of main portal vein, steatosis, original liver volume and spleen volume, were investigated as potential predictors of liver regeneration. Future remnant liver volume was …

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e…

2022

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicat…

LAPAROSCOPIC LEFT LIVER SECTIONECTOMY (LLLS) FOR PEDIATRIC LIVING RELATED LIVER TRANSPLANTATION (LRLT)

2011

PURPOSE: LRLT in children is a method to provide organs for transplantation. We report 2 cases of LLLS for pediatric LRLT. METHOD: Donor position: lithotomy with surgeon in French position. Trocars: three 12 mm, placed 2 cm upper the supra-umbilical mid-line and sub-costal bi-lateral on the nipple lines; one 5 mm in epigastrium. Special instrumentation: harmonic scissor, ligasure®, Hem-O-Lock clips, and Endo Catch-II® bag. Main steps: division of round, falciform, left triangular ligaments and of lesser omentum; inspection of anatomy; hepatic hilum dissection with exposure of the left hepatic artery; dissection of the right side of the falciform ligament with exposure of the left branch of …

Additional file 1 of Case report: Trans-papillary free stenting of the cystic duct and of the common bile duct in a double biliary ducts anastomoses …

2021

Additional file 1: Video. Imaging evaluation and surgical maneuvers.