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Gandhi KD, Taweesedt PT, Sharma M, Surani S. Hepatopulmonary syndrome: An update. World J Hepatol 2021; 13:1699-1706. [PMID: 34904039 PMCID: PMC8637683 DOI: 10.4254/wjh.v13.i11.1699] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/25/2021] [Accepted: 08/31/2021] [Indexed: 02/06/2023] Open
Abstract
Hepatopulmonary syndrome (HPS) is characterized by defects in oxygenation caused by intra-pulmonary vasodilation occurring because of chronic liver disease, portal hypertension, or congenital portosystemic shunts. Clinical implications of portal hypertension are very well-known, however, awareness of its effect on multiple organs such as the lungs are less known. The presence of HPS in chronic liver disease is associated with increased mortality. Medical therapies available for HPS have not been proven effective and definitive treatment for HPS is mainly liver transplantation (LT). LT improves mortality for patients with HPS drastically. This article provides a review on the definition, clinical presentation, diagnosis, and management of HPS.
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Affiliation(s)
- Kejal D Gandhi
- Department of Internal Medicine, Medstar Washington Hospital Center/Georgetown University, Washigton, DC 20010, United States
| | - Pahnwat Tonya Taweesedt
- Department of Medicine, Corpus Christi Medical Center, Corpus Christi, TX 78412, United States
| | - Munish Sharma
- Department of Medicine, Corpus Christi Medical Center, Corpus Christi, TX 78412, United States
| | - Salim Surani
- Department of Medicine, Texas A&M University, Bryan, TX 78413, United States
- Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905, United States
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Lim DJ. Methylene Blue-Based Nano and Microparticles: Fabrication and Applications in Photodynamic Therapy. Polymers (Basel) 2021; 13:3955. [PMID: 34833254 PMCID: PMC8618133 DOI: 10.3390/polym13223955] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 12/13/2022] Open
Abstract
Methylene blue (MB) has been used in the textile industry since it was first extracted by the German chemist Heinrich Caro. Its pharmacological properties have also been applied toward the treatment of certain diseases such as methemoglobinemia, ifosfamide-induced encephalopathy, and thyroid conditions requiring surgery. Recently, the utilization of MB as a safe photosensitizer in photodynamic therapy (PDT) has received attention. Recent findings demonstrate that photoactivated MB exhibits not only anticancer activity but also antibacterial activity both in vitro and in vivo. However, due to the hydrophilic nature of MB, it is difficult to create MB-embedded nano- or microparticles capable of increasing the clinical efficacy of the PDT. This review aims to summarize fabrication techniques for MB-embedded nano and microparticles and to provide both in vitro and in vivo examples of MB-mediated PDT, thereby offering a future perspective on improving this promising clinical treatment modality. We also address examples of MB-mediated PDT in both cancer and infection treatments. Both in-vitro and in-vivo studies are summarized here to document recent trends in utilizing MB as an effective photosensitizer in PDT. Lastly, we discuss how developing efficient MB-carrying nano- and microparticle platforms would be able to increase the benefits of PDT.
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Affiliation(s)
- Dong-Jin Lim
- Department of Otolaryngology Head & Neck Surgery, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA
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Del Valle K, DuBrock HM. Hepatopulmonary Syndrome and Portopulmonary Hypertension: Pulmonary Vascular Complications of Liver Disease. Compr Physiol 2021; 11:3281-3302. [PMID: 34636408 DOI: 10.1002/cphy.c210009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pulmonary vascular disease is a frequent complication of chronic liver disease and portal hypertension, affecting up to 30% of patients. There are two distinct pulmonary vascular complications of liver disease: hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH). HPS affects 25% of patients with chronic liver disease and is characterized by intrapulmonary vasodilatation and abnormal arterial oxygenation. HPS negatively impacts quality of life and is associated with a 2-fold increased risk of death compared to controls with liver disease without HPS. Angiogenesis, endothelin-1 mediated endothelial dysfunction, monocyte influx, and alveolar type 2 cell dysfunction seem to play important roles in disease pathogenesis but there are currently no effective medical therapies. Fortunately, HPS resolves following liver transplant (LT) with improvements in hypoxemia. POPH is a subtype of pulmonary arterial hypertension (PAH) characterized by an elevated mean pulmonary arterial pressure and pulmonary vascular resistance in the setting of normal left-sided filling pressures. POPH affects 5% to 6% of patients with chronic liver disease. Although the pathogenesis has not been fully elucidated, endothelial dysfunction, inflammation, and estrogen signaling have been identified as key pathways involved in disease pathogenesis. POPH is typically treated with PAH targeted therapy and may also improve with liver transplantation in selected patients. This article highlights what is currently known regarding the diagnosis, management, pathobiology, and outcomes of HPS and POPH. Ongoing research is needed to improve understanding of the pathophysiology and outcomes of these distinct and often misunderstood pulmonary vascular complications of liver disease. © 2021 American Physiological Society. Compr Physiol 11:1-22, 2021.
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Raghunathan V, Mohan N, Dhaliwal M, Bhangui P, Vohra V, Soin AS. Pediatric liver transplantation in severe hepatopulmonary syndrome and use of inhaled nitric oxide for post-transplant hypoxemia-a single center experience. Pediatr Transplant 2020; 24:e13792. [PMID: 32881212 DOI: 10.1111/petr.13792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 06/13/2020] [Accepted: 06/22/2020] [Indexed: 02/06/2023]
Abstract
Data on pediatric patients with HPS undergoing LT are limited. Our aim was to study the spectrum and outcomes of pediatric patients with HPS undergoing LDLT. The role ofiNO for post-LDLT refractory hypoxemia was also assessed. Patients (aged < 18 years) undergoing LT were retrospectively studied. HPS was diagnosed based on European Respiratory Society Taskforce 2004 criteria. HPS was graded based on oxygenation criteria and contrast-enhanced echocardiogram. Post-operative course was studied. Refractory post-operative hypoxemia was treated with iNO by institutionally developed protocol. 23/150 pediatric patients undergoing LDLT had HPS. BA was the most common underlying cause (52.2%). By oxygenation criteria, 6 (26.1%) had VS-HPS. VS-HPS was associated with longer LOS (p = .031) and prolonged oxygen requirement (p = .001) compared with other HPS patients. 4/6 patients with VS-HPS had pO2 < 45 mm Hg. Among these, 2 developed ICH post-operatively and 1 died. 3 developed refractory post-operative hypoxemia, successfully treated with iNO. Mean duration of iNO was 26.3 days. In the group of patients with HPS, the incidence of HAT and portal vein thrombosis was 17.3% and 4.3%, respectively. One year post-LDLT survival of patients with HPS was similar to non-HPS patients (86.9% vs 94.4%; p = .88). We concluded that, pediatric patients with VS-HPS, especially those with pre-operative pO2 < 45 mm Hg, have long and difficult post-LT course. Refractory postoperative hypoxemia can be successfully overcome with strategic use of iNO. Vigilant monitoring and good intensive care support are essential.
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Affiliation(s)
- Veena Raghunathan
- Department of Pediatric Critical Care, Medanta The Medicity, Gurgaon, India
| | - Neelam Mohan
- Department of Pediatric Gastroenterology, Hepatology & Liver Transplant, Medanta The Medicity, Gurgaon, India
| | - Maninder Dhaliwal
- Department of Pediatric Critical Care, Medanta The Medicity, Gurgaon, India
| | - Prashant Bhangui
- Institute of Liver Transplant & Regenerative Medicine, Medanta The Medicity, Gurgaon, India
| | - Vijay Vohra
- Institute of Liver Transplant & Regenerative Medicine, Medanta The Medicity, Gurgaon, India
| | - Arvinder Singh Soin
- Institute of Liver Transplant & Regenerative Medicine, Medanta The Medicity, Gurgaon, India
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Abstract
Hepatopulmonary syndrome (HPS) is a pulmonary complication observed in patients with chronic liver disease and/or portal hypertension, attributable to an intrapulmonary vascular dilatation that may induce severe hypoxemia. Microvascular dilation and angiogenesis in the lung have been identified as pathologic features that drive gas exchange abnormalities in experimental HPS. Pulse oximetry is a useful screening test for HPS, which can guide subsequent use of arterial blood gases. Contrast-enhanced echocardiography, perfusion lung scanning, and pulmonary arteriography are three currently used diagnostic imaging modalities that identify the presence of intrapulmonary vascular abnormalities. The presence of HPS increases mortality and impairs quality of life, but is reversible with liver transplantation. No medical therapy is established as effective for HPS. At the present time, liver transplantation is the only available treatment for HPS.
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Affiliation(s)
- Yong Lv
- Department of Liver Disease, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, China,
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Raevens S, Geerts A, Van Steenkiste C, Verhelst X, Van Vlierberghe H, Colle I. Hepatopulmonary syndrome and portopulmonary hypertension: recent knowledge in pathogenesis and overview of clinical assessment. Liver Int 2015; 35:1646-60. [PMID: 25627425 DOI: 10.1111/liv.12791] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 01/17/2015] [Indexed: 12/14/2022]
Abstract
Hepatopulmonary syndrome and portopulmonary hypertension are cardiopulmonary complications, which are not infrequently seen in patients with liver disease and/or portal hypertension. These entities are both clinically and pathophysiologically different: the hepatopulmonary syndrome is characterized by abnormal pulmonary vasodilation and right-to-left shunting resulting in gas exchange abnormalities, whereas portopulmonary hypertension is caused by pulmonary artery vasoconstriction leading to hemodynamic failure. As both hepatopulmonary syndrome and portopulmonary hypertension are associated with significantly increased morbidity and mortality, and as these patients are commonly asymptomatic, all liver transplantation candidates should be actively screened for the presence of these two complications. The aim of is this review is to provide an overview on the hepatopulmonary syndrome and portopulmonary hypertension with primary focus on diagnosis and recent knowledge regarding pathogenesis and therapeutic targets.
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Affiliation(s)
- Sarah Raevens
- Department of Gastroenterology and Hepatology, Ghent University Hospital, Ghent, Belgium
| | - Anja Geerts
- Department of Gastroenterology and Hepatology, Ghent University Hospital, Ghent, Belgium
| | - Christophe Van Steenkiste
- Department of Gastroenterology and Hepatology, Ghent University Hospital, Ghent, Belgium.,Department of Gastroenterology and Hepatology, Maria Middelares Hospital, Ghent, Belgium
| | - Xavier Verhelst
- Department of Gastroenterology and Hepatology, Ghent University Hospital, Ghent, Belgium
| | - Hans Van Vlierberghe
- Department of Gastroenterology and Hepatology, Ghent University Hospital, Ghent, Belgium
| | - Isabelle Colle
- Department of Gastroenterology and Hepatology, Ghent University Hospital, Ghent, Belgium.,Department of Gastroenterology and Hepatology, Algemeen Stedelijk Ziekenhuis ASZ, Aalst, Belgium
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Nayyar D, Man HSJ, Granton J, Lilly LB, Gupta S. Proposed management algorithm for severe hypoxemia after liver transplantation in the hepatopulmonary syndrome. Am J Transplant 2015; 15:903-13. [PMID: 25649047 PMCID: PMC5132094 DOI: 10.1111/ajt.13177] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 12/08/2014] [Accepted: 12/19/2014] [Indexed: 01/25/2023]
Abstract
The hepatopulmonary syndrome (HPS) is defined as the triad of liver disease, intrapulmonary vascular dilatation, and abnormal gas exchange, and is found in 10-32% of patients with liver disease. Liver transplantation is the only known cure for HPS, but patients can develop severe posttransplant hypoxemia, defined as a need for 100% inspired oxygen to maintain a saturation of ≥85%. This complication is seen in 6-21% of patients and carries a 45% mortality. Its management requires the application of specific strategies targeting the underlying physiologic abnormalities in HPS, but awareness of these strategies and knowledge on their optimal use is limited. We reviewed existing literature to identify strategies that can be used for this complication, and developed a clinical management algorithm based on best evidence and expert opinion. Evidence was limited to case reports and case series, and we determined which treatments to include in the algorithm and their recommended sequence based on their relative likelihood of success, invasiveness, and risk. Recommended therapies include: Trendelenburg positioning, inhaled epoprostenol or nitric oxide, methylene blue, embolization of abnormal pulmonary vessels, and extracorporeal life support. Availability and use of this pragmatic algorithm may improve management of this complication, and will benefit from prospective validation.
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Affiliation(s)
- D. Nayyar
- Li Ka Shing Knowledge Institute of St. Michael's HospitalTorontoCanada
| | - H. S. J. Man
- Department of MedicineUniversity of TorontoTorontoCanada,Division of RespirologyDepartment of MedicineUniversity Health NetworkTorontoCanada
| | - J. Granton
- Department of MedicineUniversity of TorontoTorontoCanada,Division of RespirologyDepartment of MedicineUniversity Health NetworkTorontoCanada
| | - L. B. Lilly
- Department of MedicineUniversity of TorontoTorontoCanada,Division of Gastroenterology and MultiOrgan Transplant ProgramUniversity Health NetworkTorontoCanada
| | - S. Gupta
- Li Ka Shing Knowledge Institute of St. Michael's HospitalTorontoCanada,Department of MedicineUniversity of TorontoTorontoCanada,Division of RespirologyDepartment of MedicineSt. Michael's HospitalTorontoCanada
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Abstract
The hepatopulmonary syndrome (HPS) is a pulmonary complication of cirrhosis and/or portal hypertension whereby patients develop hypoxemia as a result of alterations in pulmonary microvascular tone and architecture. HPS occurs in up to 30% of patients with cirrhosis. Although the degree of hypoxemia does not reliably correlate with the severity of liver disease, patients with HPS have a higher mortality than do patients with cirrhosis without the disorder. There has been progress into defining the mechanisms that lead to hypoxemia in HPS, but to date there are no therapeutic options for HPS aside from liver transplantation.
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Pharmacological treatment for hepatopulmonary syndrome. BIOMED RESEARCH INTERNATIONAL 2013; 2013:670139. [PMID: 24102057 PMCID: PMC3786536 DOI: 10.1155/2013/670139] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 07/30/2013] [Accepted: 08/12/2013] [Indexed: 12/12/2022]
Abstract
AIM Hepatopulmonary syndrome is a pulmonary dysfunction in the context of liver cirrhosis characterized by arterial deoxygenation. Affected patients have increased morbidity and mortality, and many of them expire before undergoing liver transplantation. Therefore, finding medical therapy as a bridge to transplantation or as a final treatment is necessary. In this study, we aimed to review the current literature about pharmacological options available for treatment of hepatopulmonary syndrome. METHODS A PubMED and Scopus search was conducted in January 2013 on the English literature published in any time period to find human and animal studies reporting pharmacological therapy of hepatopulmonary syndrome. RESULTS Out of 451 studies, 29 relevant articles were included. The number of patients, type, dose, duration, and mechanism of drugs in these studies was extracted and summarized separately. Most of pharmacologic agents act through inhibition of nitric oxide synthase and reduction in nitric oxide production, inactivation of endothelin-1, and treatment of bacterial translocation and pulmonary angiogenesis. CONCLUSION Several drugs have been applied for the treatment of HPS with conflicting results. However, no large randomized trial has been conducted probably due to low number of patients. Multicentered clinical trials are necessary to investigate these drugs.
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Abstract
Few prognostic indicators and outcomes reported for patients who have hepatopulmonary syndrome can be consistently reproduced between institutions. The lack of practice recommendations based upon consistent and predictable outcomes creates uncertainty for physicians trying to make the best patient choices. With the scarcity of donor organs, these issues are of particular importance when transplantation in considered as a treatment option. Much uncertainty arises from the basic tasks of making an accurate diagnosis in patients who have symptoms suggestive of hepatopulmonary syndrome. This article focuses on problems that underlie diagnostic accuracy and uses this information to appraise critically outcomes literature.
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Affiliation(s)
- M Susan Mandell
- University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Denver, CO 80262, USA.
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Mazzeo AT, Lucanto T, Santamaria LB. Hepatopulmonary syndrome: a concern for the anesthetist? Pre-operative evaluation of hypoxemic patients with liver disease. Acta Anaesthesiol Scand 2004; 48:178-86. [PMID: 14995940 DOI: 10.1111/j.0001-5172.2004.00282.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Liver cirrhosis and other chronic hepatic diseases are followed in a subset of affected patients by gas exchange abnormalities resulting from a syndrome called hepatopulmonary syndrome (HPS). The structural basis of this clinical entity is an alteration of pulmonary vasculature resulting in abnormal vasodilatation and mismatching of ventilation and perfusion of the lung. Dilatation of the capillary bed near the gas exchange area is the most important factor implicated; it precludes O2 molecules diffusing to the centrum of the dilated vessels to oxygenate venous blood. Contrast (microbubbles) echocardiography and lung perfusion scan are, respectively, the screening tests with the highest sensitivity and specificity for HPS diagnosis. Because of the high morbidity and mortality of HPS, clinicians have been trying to understand the pathophysiology of pulmonary vasodilatation in the hope that the process can be reversed pharmacologically or surgically. An imbalance between production and clearance of vasoactive circulating substances has been implicated in the pathogenesis of HPS with glucagon and nitric oxide among the principal responsible factors. To date various molecules have been implicated for therapy but without definitive positive results. Liver transplantation remains the only real therapy for HPS, and resolution of gas exchange defects outlines the possible functional reversible nature of vascular abnormalities of this syndrome. The need to perform surgery under general anesthesia for hepatic and extrahepatic procedures in patients with HPS is followed by an increased peri-operative risk. The authors emphasize the role of pre-operative clinical evaluation for proper patient management during the peri-operative period.
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Affiliation(s)
- A T Mazzeo
- Department of Neuroscience, Psychiatric and Anesthesiological Sciences, Section of Anesthesiology and Intensive Care, University Hospital Policlinico G. Martino, Via Consolare Valeria, 98121 Messina, Italy.
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Zhang XJ, Katsuta Y, Akimoto T, Ohsuga M, Aramaki T, Takano T. Intrapulmonary vascular dilatation and nitric oxide in hypoxemic rats with chronic bile duct ligation. J Hepatol 2003; 39:724-30. [PMID: 14568253 DOI: 10.1016/s0168-8278(03)00430-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND/AIMS Nitric oxide (NO) has been suggested as the major cause of pulmonary vascular dilatation and hypoxemia in hepatopulmonary syndrome (HPS). The aim of this study was to assess the effect of NO on arterial oxygenation in rats with common bile duct ligation (CBDL rats), a model of HPS. METHODS Arterial blood gases were measured in 44 CBDL rats and 44 Sham rats under unrestrained conditions. Intrapulmonary shunting was assessed with (141)Ce-labeled microspheres (15-mum diameter) and serum nitrate/nitrite levels were measured by HPLC. The effect of NOS inhibition on A-aDO(2) was studied using L-NAME. RESULTS A decrease of PaO(2) below 82.7 mmHg (the mean value-2sigma in Sham rats) was seen in 43% of CBDL rats. Intrapulmonary shunting was greater in CBDL rats than in Sham rats (P<0.001). A correlation between the extent of shunting and A-aDO(2) was found in all animals studied (r=0.89, P<0.001, n=16). Serum levels of nitrate/nitrite increased significantly across the lungs, and the increase was significantly correlated with A-aDO(2) in the total population of animals studied. Administration of L-NAME to CBDL rats achieved a significant improvement of A-aDO(2). CONCLUSIONS These results suggest that pulmonary vascular dilatation due to NO leads to hypoxemia in CBDL rats.
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Affiliation(s)
- Xue-Jun Zhang
- First Department of Internal Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan.
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Abstract
The unique pathophysiology of patients with end-stage liver disease has important implications for their critical care treatment, particularly in the postoperative state. To gauge hemodynamic parameters and responses, each patient must be carefully evaluated for their place in the clinical spectrum of cirrhosis and portal hypertension. Although the data are limited, the biology of the consequences of liver disease is emphasized by novel treatments of hepatorenal syndrome, portopulmonary hypertension, and hepatopulmonary syndrome. These issues become more relevant with increased adult-to-adult living donor liver transplantation, in which technical considerations may further complicate the general treatment of the postoperative transplant patient.
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Affiliation(s)
- Ian D McGilvray
- Department of Surgery, Division of General Surgery, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada
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