Artificial kidney: Challenges and opportunities.

This review aims to present the developments occurring in the field of artificial organs and particularly focuses on the presentation of developments in artificial kidneys. The challenges for biomedical engineering involved in overcoming the potential difficulties are showcased, as well as the importance of interdisciplinary collaboration in this marriage of medicine and technology. In this review, modern artificial kidneys and the research efforts trying to provide and promise artificial kidneys are presented. But what are the problems faced by each technology and to what extent is the effort enough to date?

Hepatic ischemia-reperfusion syndrome and its effect on the cardiovascular system: The role of treprostinil, a synthetic prostacyclin analog.

Hepatic ischemia-reperfusion syndrome has been the subject of intensive study and experimentation in recent decades since it is responsible for the outcome of several clinical entities, such as major hepatic resections and liver transplantation. In addition to the organ's post reperfusion injury, this syndrome appears to play a central role in the dysfunction of distant tissues and systems. Thus, continuous research should be directed toward finding effective therapeutic options to improve the outcome and reduce the postoperative morbidity and mortality rates. Treprostinil is a synthetic analog of prostaglandin I2, and its experimental administration has shown encouraging results. It has already been approved by the Food and Drug Administration in the United States for pulmonary arterial hypertension and has been used in liver transplantation, where preliminary encouraging results showed its safety and feasibility by using continuous intravenous administration at a dose of 5 ng/kg/min. Treprostinil improves renal and hepatic function, diminishes hepatic oxidative stress and lipid peroxidation, reduces hepatictoll-like receptor 9 and inflammation, inhibits hepatic apoptosis and restores hepatic adenosine triphosphate (ATP) levels and ATP synthases, which is necessary for functional maintenance of mitochondria. Treprostinil exhibits vasodilatory properties and antiplatelet activity and regulates proinflammatory cytokines; therefore, it can potentially minimize ischemia-reperfusion injury. Additionally, it may have beneficial effects on cardiovascular parameters, and much current research interest is concentrated on this compound.

Impact and management of COVID-19 in liver transplant candidates and recipients.

The COVID-19 outbreak has had severe consequences for global public health, medical communities, and the socioeconomic status of a considerable number of countries. The emergence of COVID-19 has also significantly impacted the world of liver transplantation (LT). Studies from transplantation centers around the world have shown that LTs during the COVID-19 pandemic have been restricted because of the high risk of serious COVID-19 infection in this population. According to the Centers for Disease Control and Prevention, patients with liver disease are considered at higher risk for severe COVID-19 infection. In March 2020, the American Association for the Study of Liver Diseases recommended that LT should be limited to emergency cases. The COVID-19 treatment guidelines published by the National Institutes of Health are being constantly updated according to new epidemiology trends and treatment regimens. Immunocompromised patients have a higher risk of developing severe disease or death from COVID-19 compared with the general population. In this review, we summarize the available evidence regarding treatment guidelines and considerations for the evaluation and management of LT candidates and recipients in the era of COVID-19. In addition, we present data regarding COVID-19 among LT patients in our local transplantation center.

Surgical chest complications after liver transplantation.

Liver transplantation is a major abdominal operation and the intimate anatomic relation of the liver with the right hemidiaphragm predisposes the patient to various manifestations in the chest cavity. Furthermore, chronic liver disease affects pulmonary function before and after liver transplantation resulting in a considerable percentage of patients presenting with morbidity related to chest complications. This review aims to identify the potential chest complications of surgical interest during or after liver transplantation. Complications of surgical interest are defined as those conditions that necessitate an invasive procedure (such as thoracocentesis or a chest tube placement) in the chest or a surgical intervention performed by a thoracic surgeon. These complications will be classified as perioperative and postoperative; the latter will be categorized as early and late. Although thoracocentesis or a chest tube placement is usually sufficient when invasive measures are deemed necessary, in some patients, thoracic surgical interventions are warranted. A high index of suspicion is needed to recognize and treat these conditions promptly. A close collaboration between abdominal surgeons, intensive care unit physicians and thoracic surgeons is of paramount importance.

Effects of an active lifestyle on the physical frailty of liver transplant candidates.

BACKGROUND: Liver transplantation is the most important therapeutic intervention for end-stage liver disease (ELD). The prioritization of these patients is based on the model for end-stage liver disease (MELD), which can successfully predict short-term mortality. However, despite its great validity and value, it cannot fully incor porate several comorbidities of liver disease, such as sarcopenia and physical frailty, variables that can sufficiently influence the survival of such patients. Subsequently, there is growing interest in the importance of physical frailty in regard to mortality in liver transplant candidates and recipients, as well as its role in improving their survival rates. AIM: To evaluate the effects of an active lifestyle on physical frailty on liver transplant candidates. METHODS: An observational study was performed within the facilities of the Department of Transplant Surgery of Aristotle University of Thessaloniki. Twenty liver tran splant candidate patients from the waiting list of the department were included in the study. Patients that were bedridden, had recent cardiovascular incidents, or had required inpatient treatment for more than 5 d in the last 6 mo were excluded from the study. The following variables were evaluated: Activity level via the International Physical Activity Questionnaire (IPAQ); functional capacity via the 6-min walking test (6MWT) and cardiopulmonary exercise testing; and physical frailty via the Liver Frailty Index (LFI). RESULTS: According to their responses in the IPAQ, patients were divided into the following two groups based on their activity level: Active group (A, 10 patients); and sedentary group (S, 10 patients). Comparing mean values of the recorded variables showed the following results: MELD (A: 12.05 ± 5.63 vs S: 13.99 ± 3.60; P > 0.05); peak oxygen uptake (A: 29.78 ± 6.07 mL/kg/min vs S: 18.11 ± 3.39 mL/kg/min; P < 0.001); anaerobic threshold (A: 16.71 ± 2.17 mL/kg/min vs S: 13.96 ± 1.45 mL/kg/min; P < 0.01); 6MWT (A: 458.2 ± 57.5 m vs S: 324.7 ± 55.8 m; P < 0.001); and LFI (A: 3.75 ± 0.31 vs S: 4.42 ± 0.32; P < 0.001). CONCLUSION: An active lifestyle can be associated with better musculoskeletal and functional capacity, while simultaneously preventing the evolution of physical frailty in liver transplant candidates. This effect appears to be independent of the liver disease severity.

Enhanced recovery after surgery in liver transplantation: Challenges and feasibility.

BACKGROUND: Enhanced recovery after surgery (ERAS) started a revolution that changed age-old surgical stereotypical practices regarding the overall management of the surgical patient. In the last decade, ERAS has gained significant acceptance in the community of general surgery, in addition to several other surgical specialties, as the evidence of its advantages continues to grow. One of the last remaining fields, given its significant complexity and intricate nature, is liver transplantation (LT). AIM: To investigate the existing efforts at implementing ERAS in LT. METHODS: We conducted a systematic review of the existing studies that evaluate ERAS in orthotopic LT, with a multimodal approach and focusing on measurable clinical primary endpoints, namely length of hospital stay. RESULTS: All studies demonstrated a considerable decrease in length of hospital stay, with no readmission or negative impact of the ERAS protocol applied to the postoperative course. CONCLUSIONS: ERAS is a well-validated multimodal approach for almost all types of surgical procedures, and its future in selected LT patients seems promising, as the preliminary results advocate for the safety and efficacy of ERAS in the field of LT.

Volumetric assessment of hepatic grafts using a light detection and ranging system for 3D scanning: Preliminary data.

BACKGROUND: Liver transplantation has evolved into a safe life-saving operation and remains the golden standard in the treatment of end stage liver disease. The main limiting factor in the application of liver transplantation is graft shortage. Many strategies have been developed in order to alleviate graft shortage, such as living donor partial liver transplantation and split liver transplantation for adult and pediatric patients. In these strategies, liver volume assessment is of paramount importance, as size mismatch can have severe consequences in the success of liver transplantation. AIM: To evaluate the safety, feasibility, and accuracy of light detection and ranging (LIDAR) 3D photography in the prediction of whole liver graft volume and mass. METHODS: Seven liver grafts procured for orthotopic liver transplantation from brain deceased donors were prospectively measured with an LIDAR handheld camera and their mass was calculated and compared to their actual weight. RESULTS: The mean error of all measurements was 17.03 g (range 3.56-59.33 g). Statistical analysis of the data yielded a Pearson correlation coefficient index of 0.9968, indicating a strong correlation between the values and a Student's t-test P value of 0.26. Mean accuracy of the measurements was calculated at 97.88%. CONCLUSION: Our preliminary data indicate that LIDAR scanning of liver grafts is a safe, cost-effective, and feasible method of ex vivo determination of whole liver volume and mass. More data are needed to determine the precision and accuracy of this method.

Should Deferred Stenting Still Be Considered in ST-Elevation Myocardial Infarction with High Thrombus Burden?

Patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) may demonstrate distal microvascular embolization of thrombotic materials. We retrospectively examined 20 cases displaying extensive thrombus in the infarct-related artery (IRA), treated either with a two-step procedure, with interim tirofiban infusion, or immediate stent implantation. Distal embolization tended to be more common in the latter strategy, but, overall, the outcome was comparable. Thus, a two-staged procedure may be considered in selected cases of primary PCI associated with high thrombus burden.

Selective internal radiation therapy (SIRT) before partial hepatectomy or radiofrequency destruction for treatment of hepatocellular carcinoma in cirrhotic patients: a feasibility and safety pilot study.

BACKGROUND/PURPOSE: Preoperative selective internal radiation therapy (SIRT) may improve the results of partial hepatectomy (PH) or radiofrequency destruction (RF) for hepatocellular carcinoma (HCC) in patients with cirrhosis. The aim of this study was to evaluate the feasibility and safety of this combined approach. METHODS: Patients with cirrhosis and HCC selected for PH or RF were prospectively included and systematically proposed for preoperative SIRT. Feasibility and safety of SIRT and post-SIRT PH or RF were assessed. RESULTS: Thirty patients were included. SIRT was contraindicated in seven, due to lack of access to tumour artery or to hepato-pulmonary shunts. SIRT was performed in 23 patients without significant complications. Post-SIRT, surgery was refuted in seven patients, due to tumour progression or the patient's deteriorating condition. After surgery, major complications were observed in 2/16 patients (12.5%) and one patient died 52 days post-surgery. A major tumour pathological response was seen in most patients who underwent surgery after SIRT. CONCLUSIONS: On intention-to-treat basis, the overall feasibility of combining preoperative SIRT and surgery was limited. Preoperative SIRT did not increase expected operative morbidity, but post-SIRT, a third of patients were refuted for surgery. Accurate selection criteria and potential long-term oncological benefit of this approach remains to be determined. ClinicalTrials.gov NCT01686880.

The Post-SIR-Spheres Surgery Study (P4S): Retrospective Analysis of Safety Following Hepatic Resection or Transplantation in Patients Previously Treated with Selective Internal Radiation Therapy with Yttrium-90 Resin Microspheres.

BACKGROUND: Reports show that selective internal radiation therapy (SIRT) may downsize inoperable liver tumors to resection or transplantation, or enable a bridge-to-transplant. A small-cohort study found that long-term survival in patients undergoing resection following SIRT appears possible but no robust studies on postsurgical safety outcomes exist. The Post-SIR-Spheres Surgery Study was an international, multicenter, retrospective study to assess safety outcomes of liver resection or transplantation following SIRT with yttrium-90 (Y-90) resin microspheres (SIR-Spheres®; Sirtex). METHODS: Data were captured retrospectively at participating SIRT centers, with Y-90 resin microspheres, surgery (resection or transplantation), and follow-up for all eligible patients. Primary endpoints were perioperative and 90-day postoperative morbidity and mortality. Standard statistical methods were used. RESULTS: The study included 100 patients [hepatocellular carcinoma: 49; metastatic colorectal cancer (mCRC): 30; cholangiocarcinoma, metastatic neuroendocrine tumor, other: 7 each]; 36% of patients had one or more lines of chemotherapy pre-SIRT. Sixty-three percent of patients had comorbidities, including hypertension (44%), diabetes (26%), and cardiopathy (16%). Post-SIRT, 71 patients were resected and 29 received a liver transplant. Grade 3+ peri/postoperative complications and any grade of liver failure were experienced by 24 and 7% of patients, respectively. Four patients died <90 days postsurgery; all were trisectionectomies (mCRC: 3; cholangiocarcinoma: 1) and typically had one or more previous chemotherapy lines and presurgical comorbidities. CONCLUSIONS: In 100 patients undergoing liver surgery after receiving SIRT, mortality and complication rates appeared acceptable given the risk profile of the recruited patients.

Pure laparoscopic left lateral sectionectomy in living donors: from innovation to development in France.

OBJECTIVE: In this study, we report the results obtained from 70 living donors in France. BACKGROUND: Left lateral sectionectomy for pediatric live donor liver transplantation is a well-standardized surgical procedure. Our team introduced the laparoscopic approach to live donation in 2002, and the reproducibility and safety of this method was discussed in 2006. METHODS: Between March 2001 and October 2012, a total of 70 donors underwent a liver procurement. Sixty-seven donors (95.7%) underwent a left lateral sectionectomy, and 3 underwent a left hepatectomy without middle hepatic vein procurement. All data were prospectively recorded in a database. RESULTS: Of the 70 donors, 66 (94%) liver grafts were procured by laparoscopy, whereas 4 (6%) patients required conversion into an open technique. Seventeen donors experienced complications, leading to an overall complication rate of 24.2%. Eleven donors (16%) had grade 1 complications, according to the Clavien system. Five donors (7.1%) presented grade 2 complications, and 1 donor (1.4%) had a grade 3 complication. No death occurred. Overall, patient and graft survival rates for pediatric recipients were 95% and 92% at 1 year, 95% and 88% at 3 years, and 95% and 84% at 5 years, respectively. CONCLUSIONS: The laparoscopic retrieval of the left lateral section for live donor liver transplantation is safe and reproducible and has transitioned from an innovative surgery to a development phase in France.

Two-stage hepatectomy: tape it and hang it, while you can.

BACKGROUND: Two stage hepatectomy is currently a method of choice for the treatment of multifocal bilobar hepatic lesions, especially in the setting of hepatic metastases of colorectal malignancies. We describe a technique that facilitates second-stage hepatectomy by taping the major vascular structures of the right liver and performing a hanging maneuver during the first stage. TECHNIQUE: At the first-stage hepatectomy, the right hepatic artery and the right portal branch are dissected free and taped with color-coded silicone tapes. A classic hanging maneuver is performed using a silicone loop. These three loops are left in situ until the second-stage hepatectomy. RESULTS: During the second-stage hepatectomy, the presence of the vascular tapes appears a major aid in the subsequent dissection and control of the major vascular structures, and the hanging loop helps parenchymal section and surgeon orientation, without liver mobilization. Six patients underwent this procedure. In one patient a biliary leak developed after the first-stage procedure, and this required reoperation for drainage. Although there is a risk of thrombosis in this setting, there were no vascular complications related to the tape positioning, nor was there any incidence of infection related to the use of the silicone tape. CONCLUSIONS: The technique described here has been in regular use in our department since 2009, and in our experience, it may facilitate second-stage hepatectomy.