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Ullas K Karanth - One of the best experts on this subject based on the ideXlab platform.
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insights from distribution dynamics inform strategies to conserve a Dhole cuon alpinus metapopulation in india
Scientific Reports, 2019Co-Authors: Arjun Srivathsa, Ullas K Karanth, Samba N Kumar, Madan K OliAbstract:Most large carnivore populations currently occur in heterogeneous landscapes, with source populations embedded in a matrix of human-dominated habitats. Understanding changes in distribution of endangered carnivores is critical for prioritizing and implementing conservation strategies. We examined distribution and dynamics of a Dhole Cuon alpinus metapopulation, first in 2007 and subsequently in 2015, based on indirect sign surveys across 37, 000sq. km of India’s Western Ghats. Predicted Dhole occupancy declined from 0.62 (95% CI: 0.58–0.66) in 2007 to 0.54 (95% CI: 0.50–0.58) in 2015. Occupancy was associated with abundance of primary prey species and anthropogenic disturbance. Local extinction appeared to be influenced by forest cover loss, and offset by protected reserves; colonization was influenced by occupancy in neighbouring sites. Perturbation analysis indicated that occupancy was more sensitive to local extinction within reserves and to colonization in sites abutting reserves. The Western Ghats could serve as a stronghold for the endangered Dhole, provided future colonizations are facilitated through habitat consolidation beyond reserve boundaries, and local extinctions are prevented by increasing protection efforts within select reserves. We advocate for wildlife managers to adopt a landscape-based approach and periodic monitoring to ensure persistence of the Dhole metapopulation in Western Ghats, and in other critical conservation regions across the species’ geographic range.
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on a Dhole trail examining ecological and anthropogenic correlates of Dhole habitat occupancy in the western ghats of india
PLOS ONE, 2014Co-Authors: Arjun Srivathsa, Ullas K Karanth, Krithi K Karanth, Devcharan Jathanna, Samba N KumarAbstract:Although they play a critical role in shaping ecological communities, many threatened predator species are data-deficient. The Dhole Cuon alpinus is one such rare canid with a global population thought to be <2500 wild individuals. We assessed habitat occupancy patterns of Dholes in the Western Ghats of Karnataka, India, to understand ecological and anthropogenic determinants of their distribution and habitat-use. We conducted spatially replicated detection/non-detection surveys of Dhole signs along forest trails at two appropriate scales: the entire landscape and a single wildlife reserve. Landscape-scale habitat occupancy was assessed across 38,728 km2 surveying 206 grid cells of 188-km2 each. Finer scale habitat-use within 935 km2 Bandipur Reserve was studied surveying 92 grid cells of 13-km2 km each. We analyzed the resulting data of Dhole signs using likelihood-based habitat occupancy models. The models explicitly addressed the problematic issue of imperfect detection of Dhole signs during field surveys as well as potential spatial auto-correlation between sign detections made on adjacent trail segments. We show that traditional ‘presence versus absence’ analyses underestimated Dhole habitat occupancy by 60% or 8682 km2 [naive = 0.27; (SE) = 0.68 (0.08)] in the landscape. Addressing imperfect sign detections by estimating detection probabilities [(L) (SE) = 0.12 (0.11)] was critical for reliable estimation. Similar underestimation occurred while estimating habitat-use probability at reserve-scale [naive = 0.39; (SE) = 0.71 (0.06)]. At landscape scale, relative abundance of principal ungulate prey primarily influenced Dhole habitat occupancy. Habitat-use within a reserve, however, was predominantly and negatively influenced by anthropogenic disturbance. Our results are the first rigorous assessment of Dhole occupancy at multiple spatial scales with potential conservation value. The approach used in this study has potential utility for cost-effectively assessing spatial distribution and habitat-use in other species, landscapes and reserves.
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Dhole distribution patterns.
2014Co-Authors: Arjun Srivathsa, Krithi K Karanth, Devcharan Jathanna, Samba N Kumar, Ullas K KaranthAbstract:Patterns of landscape-scale occupancy: Dhole distribution in the Western Ghats of Karnataka, India (2006–2007). (a) Naïve estimate and (b) estimated probabilities of occupancy.
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behavioural correlates of predation by tiger panthera tigris leopard panthera pardus and Dhole cuon alpinus in nagarahole india
Journal of Zoology, 2000Co-Authors: Ullas K Karanth, Melvin E SunquistAbstract:Behavioural factors that are likely to contribute to the coexistence of tiger Panthera tigris , leopard P. pardus and Dhole Cuon alpinus , were investigated in the tropical forests of Nagarahole, southern India, during 1986–1992. Examination of predator scats and kills were combined with radiotracking of four tigers, three leopards, and visual observations of a pack of Dhole. The three predators selectively killed different prey types in terms of species, size and age-sex classes, facilitating their coexistence through ecological separation. There was no temporal separation of predatory activities between tigers and leopards. Hunting activities of Dholes were temporally separated from those of the two felids to some extent. Rate of movement per unit time was higher for leopards compared to tigers during day and night. In general, the activity patterns of predators appeared to be largely related to the activities of their principal prey, rather than to mutual avoidance. The three predator species used the same areas and hunted in similar habitats, although tigers attacked their prey in slightly denser cover than leopards. Both cats attacked their prey close to habitat features that attracted ungulates. There was no evidence for inter-specific spatial exclusion among predators, resulting either from habitat specificity or social dominance behaviours. Our results suggest that ecological factors, such as adequate availability of appropriate-sized prey, dense cover and high tree densities may be the primary factors in structuring the predator communities of tropical forests. Behavioural factors such as differential habitat selection or inter-specific social dominance, which are of crucial importance in savanna habitats, might play a relatively minor role in shaping the predator communities of tropical forests.
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behavioural correlates of predation by tiger panthera tigris leopard panthera pardus and Dhole cuon alpinus in nagarahole india
Journal of Zoology, 2000Co-Authors: Ullas K Karanth, Melvin E SunquistAbstract:Behavioural factors that are likely to contribute to the coexistence of tiger Panthera tigris , leopard P. pardus and Dhole Cuon alpinus , were investigated in the tropical forests of Nagarahole, southern India, during 1986–1992. Examination of predator scats and kills were combined with radiotracking of four tigers, three leopards, and visual observations of a pack of Dhole. The three predators selectively killed different prey types in terms of species, size and age-sex classes, facilitating their coexistence through ecological separation. There was no temporal separation of predatory activities between tigers and leopards. Hunting activities of Dholes were temporally separated from those of the two felids to some extent. Rate of movement per unit time was higher for leopards compared to tigers during day and night. In general, the activity patterns of predators appeared to be largely related to the activities of their principal prey, rather than to mutual avoidance. The three predator species used the same areas and hunted in similar habitats, although tigers attacked their prey in slightly denser cover than leopards. Both cats attacked their prey close to habitat features that attracted ungulates. There was no evidence for inter-specific spatial exclusion among predators, resulting either from habitat specificity or social dominance behaviours. Our results suggest that ecological factors, such as adequate availability of appropriate-sized prey, dense cover and high tree densities may be the primary factors in structuring the predator communities of tropical forests. Behavioural factors such as differential habitat selection or inter-specific social dominance, which are of crucial importance in savanna habitats, might play a relatively minor role in shaping the predator communities of tropical forests.
Melvin E Sunquist - One of the best experts on this subject based on the ideXlab platform.
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behavioural correlates of predation by tiger panthera tigris leopard panthera pardus and Dhole cuon alpinus in nagarahole india
Journal of Zoology, 2000Co-Authors: Ullas K Karanth, Melvin E SunquistAbstract:Behavioural factors that are likely to contribute to the coexistence of tiger Panthera tigris , leopard P. pardus and Dhole Cuon alpinus , were investigated in the tropical forests of Nagarahole, southern India, during 1986–1992. Examination of predator scats and kills were combined with radiotracking of four tigers, three leopards, and visual observations of a pack of Dhole. The three predators selectively killed different prey types in terms of species, size and age-sex classes, facilitating their coexistence through ecological separation. There was no temporal separation of predatory activities between tigers and leopards. Hunting activities of Dholes were temporally separated from those of the two felids to some extent. Rate of movement per unit time was higher for leopards compared to tigers during day and night. In general, the activity patterns of predators appeared to be largely related to the activities of their principal prey, rather than to mutual avoidance. The three predator species used the same areas and hunted in similar habitats, although tigers attacked their prey in slightly denser cover than leopards. Both cats attacked their prey close to habitat features that attracted ungulates. There was no evidence for inter-specific spatial exclusion among predators, resulting either from habitat specificity or social dominance behaviours. Our results suggest that ecological factors, such as adequate availability of appropriate-sized prey, dense cover and high tree densities may be the primary factors in structuring the predator communities of tropical forests. Behavioural factors such as differential habitat selection or inter-specific social dominance, which are of crucial importance in savanna habitats, might play a relatively minor role in shaping the predator communities of tropical forests.
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behavioural correlates of predation by tiger panthera tigris leopard panthera pardus and Dhole cuon alpinus in nagarahole india
Journal of Zoology, 2000Co-Authors: Ullas K Karanth, Melvin E SunquistAbstract:Behavioural factors that are likely to contribute to the coexistence of tiger Panthera tigris , leopard P. pardus and Dhole Cuon alpinus , were investigated in the tropical forests of Nagarahole, southern India, during 1986–1992. Examination of predator scats and kills were combined with radiotracking of four tigers, three leopards, and visual observations of a pack of Dhole. The three predators selectively killed different prey types in terms of species, size and age-sex classes, facilitating their coexistence through ecological separation. There was no temporal separation of predatory activities between tigers and leopards. Hunting activities of Dholes were temporally separated from those of the two felids to some extent. Rate of movement per unit time was higher for leopards compared to tigers during day and night. In general, the activity patterns of predators appeared to be largely related to the activities of their principal prey, rather than to mutual avoidance. The three predator species used the same areas and hunted in similar habitats, although tigers attacked their prey in slightly denser cover than leopards. Both cats attacked their prey close to habitat features that attracted ungulates. There was no evidence for inter-specific spatial exclusion among predators, resulting either from habitat specificity or social dominance behaviours. Our results suggest that ecological factors, such as adequate availability of appropriate-sized prey, dense cover and high tree densities may be the primary factors in structuring the predator communities of tropical forests. Behavioural factors such as differential habitat selection or inter-specific social dominance, which are of crucial importance in savanna habitats, might play a relatively minor role in shaping the predator communities of tropical forests.
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prey selection by tiger leopard and Dhole in tropical forests
Journal of Animal Ecology, 1995Co-Authors: Ullas K Karanth, Melvin E SunquistAbstract:1. Ecological factors influencing prey selection by tiger Panthera tigris, leopard Panthera pardus and Dhole Cuon alpinus were investigated in an intact assemblage of large mammals in the tropical forests of Nagarahole, southern India, between 1986 and 1990. 2. Densities of large herbivores were estimated using line transects, and population structures from area counts. Carnivore diets were determined from analyses of scats (faeces) and kills. Selectivity for prey species was inferred from likelihood ratio tests comparing observed counts of scats to hypothesized scat frequencies generated from prey density estimates using parametric bootstrap simulations. Predator selectivity for size, age, sex and physical condition of prey was estimated using selection indices. 3. Ungulate and primate prey attained a density of 91 animals km -2 and comprised 89-98% of the biomass killed. Predators showed significant (P < 0.05) selectivity among prey species. Gaur Bos gaurus were preferred by tigers, whereas wild pig Sus scrofa were under-represented in leopard diet, and langur Presbytis entellus under-represented in Dhole diet. 4. Tigers selected prey weighing more than 176 kg, whereas leopard and Dhole focused on prey in the 30-175 kg size class. The average weights of principal prey killed by tiger, leopard and Dhole were, respectively, 91.5 kg, 37.6 kg and 43.4 kg. Tiger predation was biased towards adult males in chital, sambar and wild pig, and towards young gaur. Dholes selectively preyed on adult male chital, whereas leopards did not. 5. These findings suggest that if there is choice, large carnivores selectively kill larger prey, and non-selective predation patterns reported from other tropical forests may be the result of scarcity of large prey. Because availability of prey in the appropriate size classes is not a limiting resource, selective predation may facilitate large carnivore coexistence in Nagarahole. Community structures of large carnivores in tropical forests may be highly sensitive to natural or human-induced variations in the relative densities of different size classes of prey.
Phuntsho Thinley - One of the best experts on this subject based on the ideXlab platform.
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understanding human canid conflict and coexistence socioeconomic correlates underlying local attitude and support toward the endangered Dhole cuon alpinus in bhutan
Frontiers in Conservation Science, 2021Co-Authors: Phuntsho Thinley, Rajanathan Rajaratnam, Lam Norbu, Lungten Dorji, Jigme Tenzin, Chhimi Namgyal, Choney Yangzom, Tashi Wangchuk, Sonam Wangdi, Tshering DendupAbstract:Understanding human-canid conflict and coexistence must focus on documenting human-canid interactions and identifying underlying drivers of reciprocal human attitude which enables appropriate strategies to minimize conflict and forge coexistence. The Dhole (Cuon alpinus), Asia’s most widely distributed wild canid, is highly threatened from human persecution and anthropogenic activities. Despite its ‘Endangered’ status, ecological role as an apex predator, and negative interactions with humans, Dhole-specific attitude studies are limited, thus hindering the development of a comprehensive Dhole conservation strategy. Here, we investigate the influence of socio-economic factors of age, gender, income, residency inside/outside a protected area (PA), and other variables (cultural beliefs, livestock loss, and quantity of livestock loss) on local people’s attitudes and support for Dhole conservation in the Himalayan Kingdom of Bhutan. We conducted a semi-structured questionnaire survey of 1,444 households located within PA and non-PA from four representative regions in the country. Using R programming, we ran a Pearson’s chi-square test of independence to test overall difference in attitude and support for Dhole conservation, followed by recursive partitioning through a conditional inference regression tree to identify their significant covariates with the highest explanatory power. Majority (79.1%) of respondents (χ^2 = 488.6; df = 1; p < 0.001) disliked the Dhole over those who liked it. More than half (57.7%) (χ^2 = 412.7; df = 2; p < 0.001) opposed Dhole conservation over those who either supported or remained neutral. Experience of livestock loss to Dholes was the primary (p < 0.001) factor influencing negative attitude and opposition to Dhole conservation, despite an acknowledgement of the Dhole’s ecological role in controlling agricultural crop predators. Our study, which is the first-ever survey in Bhutan solely focused on investigating human attitudes and perceptions toward the Dhole, indicates that livestock loss to Dholes transcends all positive attitudes to the species and drives a predominant dislike and opposition to its conservation. To improve attitude and support toward the Dhole and to foster Dhole-human coexistence, livestock predation by Dholes needs alleviation by improving existing animal husbandry, in conjunction with promoting conservation awareness on this species.
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conserving an endangered canid assessing distribution habitat protection and connectivity for the Dhole cuon alpinus in bhutan
Frontiers in Conservation Science, 2021Co-Authors: Phuntsho Thinley, Rajanathan Rajaratnam, Jan F. Kamler, Cheten WangmoAbstract:Most canids face population declines and range contractions worldwide. Although the Dhole (Cuon alpinus) is widely distributed across ten countries in South and Southeast Asia, limited studies exist on this species. Despite its globally ‘Endangered’ status and ecological role as an apex predator, assessments on its distribution are limited to a few landscapes and countries. This explains the lack of a Dhole-specific species conservation plan in most range countries, including Bhutan where no current population estimate exists. The species has also recovered from a country-wide poisoning campaign in the 1970s and 80s. In this study, we determine the Dhole’s distribution pattern and assess the protection and connectivity of Dhole habitat in Bhutan. We anticipated Dholes to be extant within their habitat well represented in protected areas (PAs) and biological corridors (BCs). We used 721 georeferenced Dhole occurrence records and eight environmental variables in MaxEnt software to model potential Dhole distribution and habitat suitability. The model output was overlaid on the spatial layers of PAs and BCs to assess habitat protection and connectivity. As anticipated, we found the Dhole widely distributed in all districts, PAs, and BCs in Bhutan. Dholes were recorded at the highest elevation range limit of 4,980 m above sea level, which overlapped with the ‘Vulnerable’ snow leopard (Panthera uncia). Our model identified 72% (27,634 km2) of the country as suitable areas for Dholes, of which, 31% (11,899 km2) was highly suitable and 41% (15,735 km2) was moderately suitable. Contrary to our expectation, PAs and BCs encompassed only 29% (8,046 km2) and 12% (3,185 km2) of suitable areas for Dholes, respectively. A vast majority of the areas we deemed suitable for Dholes currently remain unprotected, thus making Dholes more vulnerable to human persecution and local extermination. We recommend adjusting PA boundaries to fully encompass suitable Dhole habitat, and also advocate improved livestock husbandry to reduce Dhole related livestock predation and minimize conflict, thereby ensuring its long-term survival in Bhutan.
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Understanding Human–Canid Conflict and Coexistence: Socioeconomic Correlates Underlying Local Attitude and Support Toward the Endangered Dhole (Cuon alpinus) in Bhutan
'Frontiers Media SA', 2021Co-Authors: Phuntsho Thinley, Rajanathan Rajaratnam, Lam Norbu, Lungten Dorji, Jigme Tenzin, Chhimi Namgyal, Choney Yangzom, Tashi Wangchuk, Sonam WangdiAbstract:Understanding human–canid conflict and coexistence must focus on documenting human–canid interactions and identifying the underlying drivers of reciprocal human attitude which enables appropriate strategies to minimize conflict and forge coexistence. The Dhole (Cuon alpinus), Asia's most widely distributed wild canid, is highly threatened by human persecution and anthropogenic activities. Despite its “endangered” status, its ecological role as an apex predator, negative interactions with humans, and Dhole-specific attitude studies are limited, thus hindering the development of a comprehensive Dhole-conservation strategy. Here, we investigate the influence of socioeconomic factors of age, gender, income, residency inside/outside a protected area (PA), and other variables (cultural beliefs, livestock loss, and quantity of livestock loss) on the attitudes of local people and support for Dhole conservation in the Himalayan Kingdom of Bhutan. We conducted a semi-structured questionnaire survey of 1,444 households located within the PA and non-PA from four representative regions in the country. Using R programming, we ran Pearson's chi-square test of independence to test the overall difference in the attitude and support for Dhole conservation, followed by recursive partitioning through a conditional inference regression tree to identify its significant covariates with the highest explanatory power. Majority (79.1%) of respondents (χ2 = 488.6; df = 1; p < 0.001) disliked the Dhole over those who liked it. More than half (57.7%) (χ2 = 412.7; df = 2; p < 0.001) opposed Dhole conservation over those who either supported or remained neutral. Experience of livestock loss to Dholes was the primary ( p < 0.001) factor influencing the negative attitude and opposition to Dhole conservation, despite an acknowledgment of the ecological role of the Dhole in controlling agricultural crop predators. Our study, which is the first-ever survey in Bhutan, solely focused on investigating human attitudes and perceptions toward the Dhole, indicating that livestock loss to Dholes transcends all positive attitudes to the species and drives a predominant dislike and opposition to its conservation. To improve the attitude and support toward the Dhole and to foster Dhole–human coexistence, livestock predation by Dholes needs alleviation by improving the existing animal husbandry, in conjunction with promoting conservation awareness on this species
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the ecological benefit of tigers panthera tigris to farmers in reducing crop and livestock losses in the eastern himalayas implications for conservation of large apex predators
Biological Conservation, 2018Co-Authors: Phuntsho Thinley, Rajanathan Rajaratnam, James P Lassoie, Stephen J Morreale, Paul D Curtis, Karl Vernes, Leki Leki, Sonam Phuntsho, Tshering DorjiAbstract:Abstract Ecologists have primarily focused their attention on how predator loss influences ecosystem structure and function in intact ecosystems, but rarely tested these ecological concepts in agricultural landscapes. We conducted a study in western Bhutan on the inter-specific dynamics between tigers, leopards, and Dholes, and their subsequent impact on livestock and crop losses faced by agro-pastoralists. We found that when a tiger was present in forests surrounding villages, leopards and Dholes occupied areas closer to village croplands and preyed on a higher relative abundance of wild herbivore crop raiders, thereby significantly reducing crop (β = −2.25, p
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distribution and habitat use of the endangered Dhole cuon alpinus pallas 1811 mammalia canidae in jigme dorji national park western bhutan
Journal of Threatened Taxa, 2017Co-Authors: Chhimi Namgyal, Phuntsho ThinleyAbstract:The Dhole is a little-studied wild canid with decreasing populations throughout its global range. We conducted this study in Bhutan’s Jigme Dorji National Park (JDNP) to establish baseline records of Dhole distribution and habitat use. We used trail transects and recorded animal presence via tracks, scats, direct sightings and camera traps. Ancillary habitat characteristics such as elevation, slope and vegetation cover were recorded to characterise habitat use. We used MaxEnt model to estimate distribution within JDNP. We recorded 609 indicators of Dhole presence over a 60-day survey period. The model estimated almost one-fourth of JDNP as having a high probability of Dhole occurrence, which closely corresponds to the distribution of cool broadleaved forests (CBLF) and areas close to human settlements. The highest number of indicators was obtained from CBLF, between slope ranges of 2 – 38 degree and elevation ranges of 1,468 m – 4,620 m above sea level, indicating a new record upper altitude limit for Dhole distribution across its global range. We highlight JDNP as an important Dhole conservation area in the Eastern Himalayas, and recommend drafting a pragmatic conservation plan that will strive to minimize conflicts with livestock owners and include key components such as farmer education and livestock insurance to cover Dhole kills.
Otto B Van Leeuwen - One of the best experts on this subject based on the ideXlab platform.
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transplantation of high risk donor livers after ex situ resuscitation and assessment using combined hypo and normothermic machine perfusion a prospective clinical trial
Annals of Surgery, 2019Co-Authors: Otto B Van Leeuwen, Yvonne De Vries, Maarten W N Nijsten, Maureen J M Werner, Aad P Van Den Berg, Masato Fujiyoshi, Rinse Ubbink, Gert Jan Pelgrim, Koen Reyntjens, Marieke T De BoerAbstract:OBJECTIVE The aim of this study was to evaluate sequential hypothermic and normothermic machine perfusion (NMP) as a tool to resuscitate and assess viability of initially declined donor livers to enable safe transplantation. SUMMARY BACKGROUND DATA Machine perfusion is increasingly used to resuscitate and test the function of donor livers. Although (dual) hypothermic oxygenated machine perfusion ([D]HOPE) resuscitates livers after cold storage, NMP enables assessment of hepatobiliary function. METHODS In a prospective clinical trial, nationwide declined livers were subjected to ex situ NMP (viability assessment phase), preceded by 1-hour DHOPE (resuscitation phase) and 1 hour of controlled oxygenated rewarming (COR), using a perfusion fluid containing an hemoglobin-based oxygen carrier. During the first 2.5 hours of NMP, hepatobiliary viability was assessed, using predefined criteria: perfusate lactate 10 mL, and bile pH >7.45. Livers meeting all criteria were accepted for transplantation. Primary endpoint was 3-month graft survival. RESULTS Sixteen livers underwent DHOPE-COR-NMP. All livers were from donors after circulatory death, with median age of 63 (range 42-82) years and median Eurotransplant donor risk index of 2.82. During NMP, all livers cleared lactate and produced sufficient bile volume, but in 5 livers bile pH remained <7.45. The 11 (69%) livers that met all viability criteria were successfully transplanted, with 100% patient and graft survival at 3 and 6 months. Introduction of DHOPE-COR-NMP increased the number of deceased donor liver transplants by 20%. CONCLUSIONS Sequential DHOPE-COR-NMP enabled resuscitation and safe selection of initially declined high-risk donor livers, thereby increasing the number of transplantable livers by 20%. TRIAL REGISTRATION www.trialregister.nl; NTR5972.
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pretransplant sequential hypo and normothermic machine perfusion of suboptimal livers donated after circulatory death using a hemoglobin based oxygen carrier perfusion solution
American Journal of Transplantation, 2019Co-Authors: Yvonne De Vries, Alix P M Matton, Maarten W N Nijsten, Maureen J M Werner, Aad P Van Den Berg, Marieke T De Boer, Carlijn I Buis, Masato Fujiyoshi, Ruben H J De Kleine, Otto B Van LeeuwenAbstract:Ex situ dual hypothermic oxygenated machine perfusion (DHOPE) and normothermic machine perfusion (NMP) of donor livers may have a complementary effect when applied sequentially. While DHOPE resuscitates the mitochondria and increases hepatic adenosine triphosphate (ATP) content, NMP enables hepatobiliary viability assessment prior to transplantation. In contrast to DHOPE, NMP requires a perfusion solution with an oxygen carrier, for which red blood cells (RBC) have been used in most series. RBC, however, have limitations and cannot be used cold. We, therefore, established a protocol of sequential DHOPE, controlled oxygenated rewarming (COR), and NMP using a new hemoglobin-based oxygen carrier (HBOC)-based perfusion fluid (DHOPE-COR-NMP trial, NTR5972). Seven livers from donation after circulatory death (DCD) donors, which were initially declined for transplantation nationwide, underwent DHOPE-COR-NMP. Livers were considered transplantable if perfusate pH and lactate normalized, bile production was >= 10 mL and biliary pH > 7.45 within 150 minutes of NMP. Based on these criteria five livers were transplanted. The primary endpoint, 3-month graft survival, was a 100%. In conclusion, sequential DHOPE-COR-NMP using an HBOC-based perfusion fluid offers a novel method of liver machine perfusion for combined resuscitation and viability testing of suboptimal livers prior to transplantation.
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hypothermic oxygenated machine perfusion reduces bile duct reperfusion injury after transplantation of donation after circulatory death livers
Liver Transplantation, 2018Co-Authors: Rianne Van Rijn, Otto B Van Leeuwen, Alix P M Matton, Laura C Burlage, Janneke Wiersemabuist, Marius C Van Den HeuvelAbstract:Dual hypothermic oxygenated machine perfusion (DHOPE) of the liver has been advocated as a method to reduce ischemia/reperfusion injury (IRI). This study aimed to determine whether DHOPE reduces IRI of the bile ducts in donation after circulatory death (DCD) liver transplantation. In a recently performed phase 1 trial, 10 DCD livers were preserved with DHOPE after static cold storage (SCS; www.trialregister.nl NTR4493). Bile duct biopsies were obtained at the end of SCS (before DHOPE; baseline) and after graft reperfusion in the recipient. Histological severity of biliary injury was graded according to an established semiquantitative grading system. Twenty liver transplantations using DCD livers not preserved with DHOPE served as controls. Baseline characteristics and the degree of bile duct injury at baseline (end of SCS) were similar between both groups. In controls, the degree of stroma necrosis (P = 0.002) and injury of the deep peribiliary glands (PBG; P = 0.02) increased after reperfusion compared with baseline. In contrast, in DHOPE-preserved livers, the degree of bile duct injury did not increase after reperfusion. Moreover, there was less injury of deep PBG (P = 0.04) after reperfusion in the DHOPE group compared with controls. In conclusion, this study suggests that DHOPE reduces IRI of bile ducts after DCD liver transplantation. Liver Transplantation 24 655-664 2018 AASLD.
Alix P M Matton - One of the best experts on this subject based on the ideXlab platform.
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pretransplant sequential hypo and normothermic machine perfusion of suboptimal livers donated after circulatory death using a hemoglobin based oxygen carrier perfusion solution
American Journal of Transplantation, 2019Co-Authors: Yvonne De Vries, Alix P M Matton, Maarten W N Nijsten, Maureen J M Werner, Aad P Van Den Berg, Marieke T De Boer, Carlijn I Buis, Masato Fujiyoshi, Ruben H J De Kleine, Otto B Van LeeuwenAbstract:Ex situ dual hypothermic oxygenated machine perfusion (DHOPE) and normothermic machine perfusion (NMP) of donor livers may have a complementary effect when applied sequentially. While DHOPE resuscitates the mitochondria and increases hepatic adenosine triphosphate (ATP) content, NMP enables hepatobiliary viability assessment prior to transplantation. In contrast to DHOPE, NMP requires a perfusion solution with an oxygen carrier, for which red blood cells (RBC) have been used in most series. RBC, however, have limitations and cannot be used cold. We, therefore, established a protocol of sequential DHOPE, controlled oxygenated rewarming (COR), and NMP using a new hemoglobin-based oxygen carrier (HBOC)-based perfusion fluid (DHOPE-COR-NMP trial, NTR5972). Seven livers from donation after circulatory death (DCD) donors, which were initially declined for transplantation nationwide, underwent DHOPE-COR-NMP. Livers were considered transplantable if perfusate pH and lactate normalized, bile production was >= 10 mL and biliary pH > 7.45 within 150 minutes of NMP. Based on these criteria five livers were transplanted. The primary endpoint, 3-month graft survival, was a 100%. In conclusion, sequential DHOPE-COR-NMP using an HBOC-based perfusion fluid offers a novel method of liver machine perfusion for combined resuscitation and viability testing of suboptimal livers prior to transplantation.
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hypothermic oxygenated machine perfusion reduces bile duct reperfusion injury after transplantation of donation after circulatory death livers
Liver Transplantation, 2018Co-Authors: Rianne Van Rijn, Otto B Van Leeuwen, Alix P M Matton, Laura C Burlage, Janneke Wiersemabuist, Marius C Van Den HeuvelAbstract:Dual hypothermic oxygenated machine perfusion (DHOPE) of the liver has been advocated as a method to reduce ischemia/reperfusion injury (IRI). This study aimed to determine whether DHOPE reduces IRI of the bile ducts in donation after circulatory death (DCD) liver transplantation. In a recently performed phase 1 trial, 10 DCD livers were preserved with DHOPE after static cold storage (SCS; www.trialregister.nl NTR4493). Bile duct biopsies were obtained at the end of SCS (before DHOPE; baseline) and after graft reperfusion in the recipient. Histological severity of biliary injury was graded according to an established semiquantitative grading system. Twenty liver transplantations using DCD livers not preserved with DHOPE served as controls. Baseline characteristics and the degree of bile duct injury at baseline (end of SCS) were similar between both groups. In controls, the degree of stroma necrosis (P = 0.002) and injury of the deep peribiliary glands (PBG; P = 0.02) increased after reperfusion compared with baseline. In contrast, in DHOPE-preserved livers, the degree of bile duct injury did not increase after reperfusion. Moreover, there was less injury of deep PBG (P = 0.04) after reperfusion in the DHOPE group compared with controls. In conclusion, this study suggests that DHOPE reduces IRI of bile ducts after DCD liver transplantation. Liver Transplantation 24 655-664 2018 AASLD.
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dual hypothermic oxygenated machine perfusion in liver transplants donated after circulatory death
British Journal of Surgery, 2017Co-Authors: Van Rianne Rijn, Alix P M Matton, Laura C Burlage, Negin Karimian, Andrie C Westerkamp, A P Van Den Berg, De Ruben Kleine, De Marieke Boer, Ton Lisman, Robert J PorteAbstract:Background Experimental studies have suggested that end-ischaemic dual hypothermic oxygenated machine perfusion (DHOPE) may restore hepatocellular energy status and reduce reperfusion injury in donation after circulatory death (DCD) liver grafts. The aim of this prospective case–control study was to assess the safety and feasibility of DHOPE in DCD liver transplantation. Methods In consecutive DCD liver transplantations, liver grafts were treated with end-ischaemic DHOPE. Outcome was compared with that in a control group of DCD liver transplantations without DHOPE, matched for donor age, donor warm ischaemia time, and recipient Model for End-stage Liver Disease (MELD) score. All patients were followed for 1 year. Results Ten transplantations involving liver grafts treated with DHOPE were compared with 20 control procedures. There were no technical problems. All 6-month and 1-year graft and patient survival rates were 100 per cent in the DHOPE group. Six-month graft survival and 1-year graft and patient survival rates in the control group were 80, 67 and 85 per cent respectively. During DHOPE, median (i.q.r.) hepatic adenosine 5′-triphosphate (ATP) content increased 11-fold, from 6 (3–10) to 66 (42–87) µmol per g protein (P = 0·005). All DHOPE-preserved livers showed excellent early function. At 1 week after transplantation peak serum alanine aminotransferase (ALT) and bilirubin levels were twofold lower in the DHOPE group than in the control group (ALT: median 966 versus 1858 units/l respectively, P = 0·006; bilirubin: median 1·0 (i.q.r. 0·7–1·4) versus 2·6 (0·9–5·1) mg/dl, P = 0·044). None of the ten DHOPE-preserved livers required retransplantation for non-anastomotic biliary stricture, compared with five of 20 in the control group (P = 0·140). Conclusion This clinical study of end-ischaemic DHOPE in DCD liver transplantation suggests that the technique restores hepatic ATP, reduces reperfusion injury, and is safe and feasible. RCTs with larger numbers of patients are warranted to assess the efficacy in reducing post-transplant biliary complications.