Trenches in Transplant Surgery

This episode explores the critical role of **lactate metabolism** as a biomarker for assessing organ quality in **Donation after Circulatory Death (DCD)** compared to **Donation after Brain Death (DBD)**. While the heart typically consumes lactate and the liver clears it, the **warm ischemia** inherent in DCD causes a shift toward anaerobic metabolism and significant lactate accumulation. To mitig...

By 2050, organ transplantation will be radically transformed—from a scarce, donor-dependent therapy into a diverse ecosystem of biological and technological solutions. Patients will receive organs from genetically engineered pigs, bioprinting labs, or even their own regenerated cells, while many others may avoid transplantation altogether through regenerative medicine, gene editing, and artificial...

Regulatory T cells (Tregs)—discovered by Shimon Sakaguchi, Mary Brunkow, and Fred Ramsdell, who were awarded the 2025 Nobel Prize—are central to inducing immune tolerance and preventing organ transplant rejection. These CD4⁺FoxP3⁺ cells suppress alloimmune responses through multiple mechanisms (IL-10, TGF-β secretion; CTLA-4–mediated dendritic cell modulation; IL-2 consumption; cytotoxic effects o...

Desensitization has transformed kidney transplantation for patients with high immunologic risk by lowering or removing antibodies that would otherwise cause graft loss. Pre- and peri-transplant plasmapheresis (therapeutic plasma exchange) with low-dose intravenous immunoglobulin (IVIG), sometimes combined with B-cell depletion (rituximab) or newer agents (imlifidase, bortezomib, daratumumab), is s...

When a deceased-donor offer arrives, the on-call surgeon rapidly weighs donor organ quality, recipient need, and logistics within OPTN/UNOS policy. For kidneys, decisions hinge on KDPI, creatinine/AKI course, machine-pump metrics, procurement biopsy (e.g., glomerulosclerosis/arteriosclerosis), HLA antibodies/virtual or physical crossmatch, and the patient’s wait time/sensitization; kidneys tolerat...

Chimerism—the coexistence of donor and recipient hematopoietic cells—has become central to understanding and inducing immune tolerance in solid organ transplantation. Early work by Owen, Medawar, and later Starzl revealed that donor “passenger leukocytes” can persist as microchimerism in recipients, reshaping the once one-way host-versus-graft paradigm into a bidirectional model. Stable mixed chim...

Following a recent New York Times report that questioned the ethics and safety of donation after circulatory death (DCD) , this episode clarifies how DCD and donation after brain death (DBD) actually work in U.S. organ procurement. We explain why DCD now accounts for ~43% of deceased donors (≈7,300 in 2024, 13,496 transplants) and how it complements the ~9,700 brain-dead donors who still provide m...

During normothermic machine perfusion (NMP), several red flags may prompt declining a liver for transplantation. The most critical biochemical warning is failure to clear lactate to <2–2.5 mmol/L within 2–3 hours, or a rebound rise after initial clearance, indicating poor hepatocellular metabolism. Persistent metabolic acidosis despite heavy bicarbonate support and sharply rising ALT/AST (espec...

Domino liver transplantation is a unique and innovative surgical strategy designed to expand the donor organ pool by utilizing the explanted liver from a patient with a non-cirrhotic metabolic liver disease—such as familial amyloid polyneuropathy or maple syrup urine disease—as a graft for a second recipient. While the donor liver carries a genetic or enzymatic defect, it remains structurally and...

This episode of TTS Podcast explores “Smarter Organ Allocation: AI, Policy, and KDPI Optimization”, focusing on how recent U.S. policy reforms like continuous distribution, kidney expedited placement protocols, and updated scoring systems (KDPI, EPTS, MELD 3.0) are reshaping transplant equity and efficiency. It examines cutting-edge AI applications in donor-recipient matching, survival prediction,...

Vascular complications after liver transplantation – HAT, HVOO, and PVT – though infrequent, demand a high index of suspicion and aggressive management. Early Doppler ultrasound monitoring and prompt imaging are essential to detect these complications in their nascent stages. Advances in surgical techniques and interventional radiology have significantly improved outcomes: for example, timely IR p...

In this episode, we explore the science and clinical importance of crossmatching in abdominal organ transplantation—focusing on kidney and liver grafts. We delve into the key differences between T cell and B cell crossmatches, examining the roles of complement-dependent cytotoxicity (CDC) and flow cytometry in detecting donor-specific antibodies (DSAs). While a positive T cell crossmatch—particula...

Combining Normothermic Regional Perfusion (NRP) with Normothermic Machine Perfusion (NMP) in DCD liver transplantation offers synergistic benefits over NMP alone by providing both early in-situ resuscitation and ex-situ viability assessment. While NMP alone improves early graft function and logistics, it does not fully prevent ischemic cholangiopathy (IC); in contrast, NRP—by rapidly restoring oxy...

Reactive care for abdominal organ failure—through costly interventions like liver, kidney, pancreas, and multivisceral transplants—imposes a substantial healthcare burden in the U.S., with first-year costs ranging from $400,000 to over $2 million per case, plus significant long-term expenses and productivity losses. While transplantation improves survival and can be cost-effective (especially kidn...

Severe acute alcoholic hepatitis (AAH), characterized by high short-term mortality (exceeding 75% at 6 months) in patients failing corticosteroid therapy (Lille score >0.45), represents a paradigm shift in liver transplantation, moving from historical contraindication to a potentially life-saving intervention for highly selected candidates. Landmark studies, notably Mathurin et al. (2011), demo...

The critical organ shortage has driven a paradigm shift in utilizing deceased donors with infectious diseases, transforming many historical absolute contraindications into relative ones through advanced diagnostics and targeted therapies. While universally fatal or untreatable infections like active rabies, prion diseases, untreated disseminated fungal infections, or multidrug-resistant sepsis rem...

Tele-transplantation in RLS currently relies overwhelmingly on tele-mentoring (remote expert guidance via video link), as pure robotic telesurgery remains technologically and financially unfeasible due to prohibitive costs, unreliable ultra-low-latency connectivity, and lack of affordable robotic systems. Successful case studies, like kidney transplant mentoring between India and the UK or foundat...

Autonomous perfusion systems powered by machine learning represent a transformative advancement in organ preservation and tissue engineering. By integrating real-time sensor data with adaptive AI algorithms—such as reinforcement learning, Gaussian processes, and predictive modeling—these systems dynamically adjust perfusion parameters to optimize oxygenation, nutrient delivery, and waste removal....

Infrared spectroscopy, including both near-infrared (NIR) and mid-infrared (MIR) modalities, is emerging as a powerful, non-invasive tool for real-time organ viability assessment in transplantation. NIR spectroscopy has been applied to monitor perfusion and oxygenation in kidney and liver grafts during surgery and preservation, with studies showing strong correlations between spectral features and...

Immersive VR training modules for liver and kidney transplantation are emerging as powerful tools in surgical education, combining anatomical accuracy, procedural simulation, and collaborative learning. Academic institutions such as Lawrence Livermore National Lab and Otto-von-Guericke University have developed VR platforms that simulate complex procedures like laparoscopic liver resections and ki...

Wearable biosensors are emerging as transformative tools for real-time immunosuppression and graft monitoring in abdominal organ transplantation. These devices—ranging from sweat and interstitial fluid sensors to subcutaneous and implantable platforms—can detect key biomarkers such as tacrolimus levels, cytokines, CRP, creatinine, and tissue oxygenation. By integrating with mobile apps and cloud-b...

Frailty and sarcopenia are highly prevalent in patients undergoing liver transplantation, with significant implications for both pre- and post-transplant outcomes. Frailty, often assessed using tools like the Liver Frailty Index (LFI), and sarcopenia, typically measured by CT-based muscle mass, independently predict increased waitlist mortality, longer hospital and ICU stays, higher risk of infect...

Reconstruction of variant hepatic artery anatomy during liver transplantation is a critical component of graft revascularization, given that up to 50% of donors exhibit anatomical variations such as replaced or accessory right or left hepatic arteries. Techniques include back-table reconstructions using Carrel or branch patches, end-to-end anastomoses, or grafting variant arteries to donor gastrod...

Blockchain technology offers a promising solution to critical challenges in global organ transplant systems, such as lack of transparency, data tampering, and inefficiencies in organ tracking and registry management. By providing a decentralized, immutable, and auditable ledger, blockchain can enhance trust among stakeholders, ensure the integrity of consent and allocation processes, and prevent f...

Artificial intelligence is transforming donor-recipient matching in abdominal organ transplantation by integrating complex datasets—such as clinical variables, imaging, genomics, and immunologic profiles—into predictive models that can optimize graft allocation and improve outcomes. Machine learning techniques like gradient boosting, random forests, and deep neural networks have demonstrated super...