Clinical Utility of the Molecular Microscope Diagnostic System in a Real-World Transplant Cohort: Moving Towards a New Paradigm.

Objectives: To evaluate the clinical implications of adjunctive molecular gene expression analysis (MMDx ) of biopsy specimens in heart transplant (HT ) recipients with suspected rejection. Introduction: Histopathological evaluation remains the standard method for rejection diagnosis in HT. However, the wide interobserver variability combined with a relatively common incidence of "biopsy-negative" rejection has raised concerns about the likelihood of false-negative results. MMDx, which uses gene expression to detect early signs of rejection, is a promising test to further refine the assessment of HT rejection. Methods: Single-center prospective study of 418 consecutive for-cause endomyocardial biopsies performed between November 2022 and May 2024. Each biopsy was graded based on histology and assessed for rejection patterns using MMDx. MMDx results were deemed positive if borderline or definitive rejection was present. The impact of MMDx results on clinical management was evaluated. Primary outcomes were 1-year survival and graft dysfunction following MMDx-guided clinical management. Secondary outcomes included changes in donor-specific antibodies, MMDx gene transcripts, and donor-derived cell-free DNA (dd-cfDNA) levels. Results: We analyzed 418 molecular samples from 237 unique patients. Histology identified rejection in 32 cases (7.7%), while MMDx identified rejection in 95 cases (22.7%). Notably, in 79 of the 95 cases where MMDx identified rejection, histology results were negative, with the majority of these cases being antibody-mediated rejection (62.1%). Samples with rejection on MMDx were more likely to show a combined elevation of dd-cfDNA and peripheral blood gene expression profiling than those with borderline or negative MMDx results (36.7% vs 28.0% vs 10.3%; p<0.001). MMDx results led to the implementation of specific antirejection protocols or changes in immunosuppression in 20.4% of cases, and in 73.4% of cases where histology was negative and MMDx showed rejection. 1-year survival was better in the positive MMDx group where clinical management was guided by MMDx results (87.0% vs 78.6%; log rank p=0.0017). Conclusions: In our cohort, MMDx results more frequently indicated rejection than histology, often leading to the initiation of antirejection treatment. Intervention guided by positive MMDx results was associated with improved outcomes.

Comparative Analysis of Ischemia-Reperfusion Injury in Heart Transplantation: A Single-Center Study Evaluating Conventional Ice-Cold Storage versus the Paragonix SherpaPak Cardiac Transport System.

BACKGROUND: Since the 2018 allocation system change in heart transplantation (HT), ischemic times have increased, which may be associated with peri-operative and post-operative complications. This study aimed to compare ischemia reperfusion injury (IRI) in hearts preserved using ice-cold storage (ICS) and the Paragonix SherpaPak TM Cardiac Transport System (CTS). METHODS: From January 2021 to June 2022, consecutive endomyocardial biopsies from 90 HT recipients were analyzed by a cardiac pathologist in a single-blinded manner: 33 ICS and 57 CTS. Endomyocardial biopsies were performed at three-time intervals post-HT, and the severity of IRI manifesting histologically as coagulative myocyte necrosis (CMN) was evaluated, along with graft rejection and graft function. RESULTS: The incidence of IRI at weeks 1, 4, and 8 post-HT were similar between the ICS and CTS groups. There was a 59.3% statistically significant reduction in CMN from week 1 to 4 with CTS, but not with ICS. By week 8, there were significant reductions in CMN in both groups. Only 1 out of 33 (3%) patients in the ICS group had an ischemic time >240 mins, compared to 10 out of 52 (19%) patients in the CTS group. During the follow-up period of 8 weeks to 12 months, there were no significant differences in rejection rates, formation of de novo donor-specific antibodies and overall survival between the groups. CONCLUSION: The CTS preservation system had similar rates of IRI and clinical outcomes compared to ICS despite longer overall ischemic times. There is significantly more recovery of IRI in the early post operative period with CTS. This study supports CTS as a viable option for preservation from remote locations, expanding the donor pool.

Validation of the HeartMate 3 survival risk score in a large left ventricular assist device center.

OBJECTIVE: The HeartMate 3 survival risk score was recently validated in the Multicenter study Of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 to predict patient-specific survival in HeartMate 3 left ventricular assist device candidates. The HeartMate 3 survival risk score stratifies individuals into tertiles according to survival probability. METHODS: We performed a single-center retrospective review of all HeartMate 3 left ventricular assist device recipients between September 2017 and August 2022. Baseline characteristics were collected from the electronic medical records. HeartMate 3 survival risk scores were calculated for all eligible patients. One- and 2-year Kaplan-Meier survival analyses were conducted. A univariate and multivariable Cox regression model was used to identify predictors. RESULTS: A total of 181 patients were included in this final analysis. The median age was 62 years, 83% were male, and 26% were Interagency Registry for Mechanically Assisted Circulatory Support Profile 1. The mean HeartMate 3 survival risk score for the entire cohort was 2.66 ± 0.66. Two-year survivals in the high, average, and low survival groups were 93.5% ± 3.2%, 81.6% ± 7.4%, and 82.0% ± 6.6%, respectively. As a continuous variable, the unadjusted HeartMate 3 survival risk score was a significant predictor of mortality (hazard ratio, 2.20; 95% CI, 1.08-4.45; P = .029). The areas under the curve were 0.70 and 0.66 at 1 and 2 years, respectively. We were unable to demonstrate the discriminatory ability of the HeartMate 3 survival risk score using the original stratification, but we found significantly increased survival in the high survival group using a binary cutoff (hazard ratio, 4.8; 95% CI, 1.01-20.9; P = .038). CONCLUSIONS: The unadjusted HeartMate 3 survival risk score was associated with postimplant survival in patients outside of the Multicenter study Of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 but did not remain an independent predictor after adjusting for ischemic etiology and severe diabetes. The HeartMate 3 survival risk score was able to identify patients at high survival using a binary cutoff, but we were unable to demonstrate its discriminatory ability among the previously published risk tertiles.

Computer-Assisted Evaluation Confirms Spontaneous Healing of Donor Site One Year following Bone Block Harvesting from Mandibular Retromolar Region-A Cohort Study.

Bone augmentation prior to dental implant placement is a common scenario in the dental implantology field. Among the important intraoral harvesting sites to obtain bone blocks is the ramus/retromolar region that has a high success rate and long-lasting alveolar ridge augmentation. Preserving the bone volume and quality at the donor site is crucial for preventing further complications or to serve as a site for re-harvesting. Healing of the intraoral donor sites has been described in the maxillofacial field. This study aimed to evaluate the spontaneous healing of the mandibular retromolar donor site utilizing computer-assisted quantification 6 and 12 months after bone harvesting. MATERIALS AND METHODS: The study was conducted on patients who underwent an alveolar ridge augmentation using an intraoral retromolar bone graft. Three CBCT scans were performed-intraoperative, and at six months and one year after the surgical procedure. By using the Materialise Mimics Innovation Suite software 26.0 features segmentation by thresholding, Hounsfield unit averaging, and superimposition of the tomographies, we could precisely quantify the healing process utilizing spatial and characteristic measures. RESULTS: In all cases, the computer-aided quantification showed that six months following surgery, the donor site had recovered up to 64.5% ± 4.24 of its initial volume, and this recovery increased to 89.2% ± 2.6 after one year. Moreover, the Hounsfield unit averaging confirmed dynamic bone quality healing, starting at 690.3 ± 81 HU for the bone block, decreasing to 102 ± 27.8 HU at six months postoperatively, and improving to 453.9 ± 91.4 HU at the donor site after a year. CONCLUSIONS: This study demonstrates that there is no need for additional replanting at the donor site following retromolar bone block harvesting, whether autogenous or allograft, since spontaneous healing occurs 12 months following the surgery.

Utility of a fusion protein T-cell co-stimulation blocker Belatacept in heart transplant recipients: Real world experience from a high volume center.

BACKGROUND: Belatacept (BTC), a fusion protein, selectively inhibits T-cell co-stimulation by binding to the CD80 and CD86 receptors on antigen-presenting cells (APCs) and has been used as immunosuppression in adult renal transplant recipients. However, data regarding its use in heart transplant (HT) recipients are limited. This retrospective cohort study aimed to delineate BTC's application in HT, focusing on efficacy, safety, and associated complications at a high-volume HT center. METHODS: A retrospective cohort study was conducted of patients who underwent HT between January 2017 and December 2021 and subsequently received BTC as part of their immunosuppressive regimen. Twenty-one HT recipients were identified. Baseline characteristics, history of rejection, and indication for BTC use were collected. Outcomes included renal function, graft function, allograft rejection and mortality. Follow-up data were collected through December 2023. RESULTS: Among 776 patients monitored from January 2017 to December 2021 21 (2.7%) received BTC treatment. Average age at transplantation was 53 years (± 12 years), and 38% were women. BTC administration began, on average, 689 [483, 1830] days post-HT. The primary indications for BTC were elevated pre-formed donor-specific antibodies in highly sensitized patients (66.6%) and renal sparing (23.8%), in conjunction with reduced calcineurin inhibitor dosage. Only one (4.8%) patient encountered rejection within a year of starting BTC. Graft function by echocardiography remained stable at 6 and 12 months posttreatment. An improvement was observed in serum creatinine levels (76.2% of patients), decreasing from a median of 1.58 to 1.45 (IQR [1.0-2.1] to [1.1-1.9]) over 12 months (p = .054). eGFR improved at 3 and 6 months compared with 3 months pre- BTC levels; however, this was not statistically significant (p = .24). Treatment discontinuation occurred in seven patients (33.3%) of whom four (19%) were switched back to full dose CNI. Infections occurred in 11 patients (52.4%), leading to BTC discontinuation in 4 patients (19%). CONCLUSION: In this cohort, BTC therapy was used as alternative immunosuppression for management of highly sensitized patients or for renal sparing. BTC therapy when combined with CNI dose reduction resulted in stabilization in renal function as measured through renal surrogate markers, which did not, however, reach statistical significance. Patients on BTC maintained a low rejection rate and preserved graft function. Infections were common during BTC therapy and were associated with medication pause/discontinuation in 19% of patients. Further randomized studies are needed to assess the efficacy and safety of BTC in HT recipients.

Long-term outcomes for pediatric heart transplant recipients transitioning to adult care teams.

BACKGROUND: There are limited data evaluating the success of a structured transition plan specifically for pediatric heart transplant (HT) recipients following their transfer of care to an adult specialist. We sought to identify risk factors for poor adherence, graft failure, and mortality following the transfer of care to adult HT care teams. METHODS: We retrospectively reviewed all patients who underwent transition from the pediatric to adult HT program at our center between January 2011 and June 2021. Demographic characteristics, comorbid conditions, and psychosocial history were collected at the time of HT, the time of transition, and the most recent follow-up. Adverse events including mortality, graft rejection, infection, and renal function were also captured before and after the transition. RESULTS: Seventy-two patients were identified (54.1% male, 54.2% Caucasian). Mean age at the time of transition was 23 years after a median of 11.6 years in the pediatric program. The use of calcineurin inhibitors was associated with reduced mortality (HR .04, 95% CI .0-.6, p = .015), while prior psychiatric hospitalization (HR 45.3, 95% CI, 6.144-333.9, p = .0001) was associated with increased mortality following transition. Medication nonadherence and young age at the time of transition were markers for high-risk individuals prior to the transition of care. CONCLUSIONS: Transition of HT recipients from a pediatric program to an adult program occurs during a vulnerable time of emerging adulthood, and we have identified risk factors for mortality following transition. Development of a formalized transition plan with a large multidisciplinary team with focused attention on high-risk patients, including those with psychiatric comorbidities, may favorably influence outcomes.

"Durable left ventricular assist devices as a bridge to transplantation in The Old and The New World".

Heart transplantation remains the gold standard treatment for end-stage heart failure patients without contraindications. However, limited donor availability and long wait times have created a need for left ventricular assist devices (LVAD) to be used as a bridge to transplantation in appropriately selected patients. Improvements in LVAD technology have resulted in improved short- and long-term outcomes, further supporting the use of these devices for a bridge-to-transplant (BTT) indication. LVAD utilization as BTT exhibits notable disparities worldwide, mainly due to variations in organ availability, allocation policies, and financial constraints. Although Europe has experienced a consistent increase in the use of LVAD for this purpose, the United Network for Organ Sharing 2018 policy amendment resulted in a significant reduction in the number of LVADs used for BTT in the US. To overcome this issue, modifications in the US allocation policy to consider factors such as days on device support, age, and type of complications may be necessary to potentially increase implantation rates.The authors provide an overview comparing the current state of heart transplantation in the US and Europe, with a particular focus on how distinct allocation policies and organ availability impact medical practices. Additionally, the review will examine critical aspects ranging from patient selection and pre-implantation optimization to post-transplant outcomes.

Hemodynamic Optimization by Invasive Ramp Test in Patients Supported With HeartMate 3 Left Ventricular Assist Device.

In patients supported by the HeartMate 3 left ventricular assist device (HM3 LVAD), pump speed adjustments may improve hemodynamics. We investigated the hemodynamic implications of speed adjustments in HM3 recipients undergoing hemodynamic ramp tests. Clinically stable HM3 recipients who underwent routine invasive hemodynamic ramp tests between 2015 and 2022 at our center were included. Filling pressure optimization, defined as central venous pressure (CVP) <12 mm Hg and pulmonary capillary wedge pressure (PCWP) <18 mm Hg, was assessed at baseline and final pump speeds. Patients with optimized pressures were compared to nonoptimized patients. Overall 60 HM3 recipients with a median age of 62 years (56, 71) and time from LVAD implantation of 187 days (124, 476) were included. Optimized filling pressures were found in 35 patients (58%) at baseline speed. Speed was adjusted in 84% of the nonoptimized patients. Consequently, 39 patients (65%) had optimized pressures at final speed. There were no significant differences in hemodynamic findings between baseline and final speeds (p > 0.05 for all). Six and 12 month readmission-free rates were higher in optimized compared with nonoptimized patients (p = 0.03 for both), predominantly due to lower cardiac readmission-free rates (p = 0.052). In stable outpatients supported with HM3 who underwent routine ramp tests, optimized hemodynamics were achieved in only 2 of 3 of the patients. Patients with optimized pressures had lower all-cause readmission rates, primarily driven by fewer cardiac-related hospitalizations.

Evolution of Mechanical Circulatory Support for advanced heart failure.

This comprehensive review highlights the significant advancements in Left Ventricular Assist Device (LVAD) therapy, emphasizing its evolution from the early pulsatile flow systems to the cutting-edge continuous-flow devices, particularly the HeartMate 3 (HM3) LVAD. These advancements have notably improved survival rates, reduced complications, and enhanced the quality of life (QoL) for patients with advanced heart failure. The dual role of LVADs, as a bridge-to-transplantation and destination therapy is discussed, highlighting the changing trends and policies in their application. The marked reduction in hemocompatibility-related adverse events (HRAE) with the HM3 LVAD, compared to previous models signifies ongoing progress in the field. Challenges such as managing major infections are discussed, including innovative solutions like energy transfer systems aimed at eliminating external drivelines. It explores various LVAD-associated complications, including HRAE, infections, hemodynamic-related adverse events, and cardiac arrhythmias, and underscores emerging strategies for predicting post-implantation outcomes, fostering a more individualized patient care approach. Tools such as the HM3 risk score are introduced for predicting survival based on pre-implant factors, along with advanced imaging techniques for improved complication prediction. Additionally, the review highlights potential new technologies and therapies in LVAD management, such as hemodynamic ramp tests for optimal speed adjustment and advanced remote monitoring systems. The goal is to automate LVAD speed adjustments based on real-time hemodynamic measurements, indicating a shift towards more effective, patient-centered therapy. The review concludes optimistically that ongoing research and potential future innovations hold the promise of revolutionizing heart failure management, paving the way for more effective and personalized treatment modalities.

The Hemodynamic Effects of Aortic Regurgitation in Patients Supported by a HeartMate 3 Left Ventricular Assist Device.

BACKGROUND: Aortic regurgitation (AR) is a common complication following left ventricular assist device (LVAD) implantation. We evaluated the hemodynamic implications of AR in patients with HeartMate 3 (HM3) LVAD at baseline and in response to speed changes. METHODS AND RESULTS: Clinically stable outpatients supported by HM3 who underwent a routine hemodynamic ramp test were retrospectively enrolled in this analysis. Patients were stratified based on the presence of at least mild AR at baseline speed. Hemodynamic and echocardiographic parameters were compared between the AR and non-AR groups. Sixty-two patients were identified. At the baseline LVAD speed, 29 patients (47%) had AR, while 33 patients (53%) did not. Patients with AR were older and supported on HM3 for a longer duration. At baseline speed, all hemodynamic parameters were similar between the groups including central venous pressure, pulmonary capillary wedge pressure, pulmonary arterial pressures, cardiac output and index, and pulmonary artery pulsatility index (p > 0.05 for all). During the subacute assessment, AR worsened in some, but not all, patients, with increases in LVAD speed. There were no significant differences in 1-year mortality or hospitalization rates between the groups, however, at 1-year, ≥ moderate AR and right ventricular failure (RVF) were detected in higher rates among the AR group compared to the non-AR group (45% vs. 0%; p < 0.01, and 75% vs. 36.8%; p = 0.02, respectively). CONCLUSIONS: In a cohort of stable outpatients supported with HM3 who underwent a routine hemodynamic ramp test, the presence of mild or greater AR did not impact the ability of HM3 LVADs to effectively unload the left ventricle during early subacute assessment. Although the presence of AR did not affect mortality and hospitalization rates, it resulted in higher rates of late hemodynamic-related events in the form of progressive AR and RVF.

Transcatheter edge-to-edge mitral valve repair in patients with acute decompensated heart failure due to severe mitral regurgitation.

BACKGROUND: Transcatheter edge-to-edge mitral valve repair (TEER) has been established as a therapy for severe symptomatic mitral regurgitation (MR) in stable patients, and it has recently emerged as a reasonable option for acutely ill patients. The aim of this study was to evaluate the safety and efficacy of TEER in hospitalized patients with acute decompensated heart failure (ADHF) and severe MR that was deemed to play a major role in their deterioration. METHODS: We included 31 patients who underwent emergent TEER for MR ≥ 3+ from 2012 to 2022 at Sheba Medical Center. Outcomes included procedural safety, procedural success, all-cause mortality, heart failure readmission, and functional improvement. Outcomes were evaluated at 3 months and at 1 year. Data were obtained retrospectively by chart review. RESULTS: Implantation of a TEER device was achieved in 97% of patients, and reduction in MR severity of at least two grades and final MR ≤ 2+ at discharge was achieved in 74%. No intra-procedural mortality or life-threatening complications were noted. Mortality at 30 days was 23%. No excess mortality occurred beyond 6 months, with a total mortality of 41%. At 1 year all survivors had MR ≤ 2+, all were free of heart failure hospitalizations, and 88% were at New York Heart Association class ≤ II. CONCLUSIONS: Mitral valve TEER for patients with ADHF and significant MR is safe, feasible, and achieves substantial reduction in MR severity. Despite high early mortality, procedural success is associated with good long-term clinical outcomes for patients surviving longer than 6 months.

Reverse Remodeling Effects of Sacubitril-Valsartan: Structural and Functional Optimization in Stage C Heart Failure.

Sacubitril-valsartan, an angiotensin receptor-neprilysin inhibitor, reduces all-cause mortality and the rate of heart failure hospitalizations in patients with heart failure with reduced ejection fraction. This study aimed to elucidate the benefits of initiating sacubitril-valsartan on ventricular remodeling in patients previously optimized on guideline-directed medical therapy. In this prospective, single-arm longitudinal study, 40 patients with heart failure with reduced ejection fraction who were optimized on guideline-directed medical therapy were transitioned to sacubitril-valsartan. The primary end point was the change in left ventricular (LV) volume at 1 year as assessed by 3-dimensional transthoracic echocardiography. Other echocardiographic end points included change in LV-function and change in right ventricular (RV) size and function. The mean age was 55 ± 12 years, and 63% were male. At 1 year, LV end-diastolic volume decreased from 242 ± 71 to 157 ± 57 ml (p <0.001) with a corresponding increase in LV ejection fraction from 32 ± 7% to 44 ± 9% (p <0.001). RV end-diastolic volume decreased from 151 ± 51 to 105 ±45 ml (p <0.001). Although RV ejection fraction did not change (51 ± 8 vs 51 ± 10; p = 0.35), RV global longitudinal strain improved from -14.9 ± 3.4 % to -19.3 ± 4.3% (p <0.001). When added to standard medical therapy for heart failure, sacubitril-valsartan induces significant remodeling of both the right and left ventricles as assessed by 3-dimensional echocardiography.

Pumping for Two: Pregnancy in Patients Supported With a Left Ventricular Assist Device.

This review discusses the challenges and outcomes associated with pregnancy during left ventricular assist device (LVAD) support. Women account for a third of the heart failure population in the United States. Left ventricular assist devices have emerged as a safe and effective treatment option for patients with advanced heart failure. Pregnancy during LVAD support can occur, and it presents significant risks to both mother and fetus, including hemodynamic stress, thrombotic events, medication-associated teratogenicity, and uterine impingement. This literature review identified 10 cases of confirmed pregnancy during LVAD support, of which eight resulted in successful births. Maternal and fetal mortality occurred in one case, and there was a spontaneous abortion in one case. The review highlights the importance of a multidisciplinary approach, promotion of shared decision-making, thoughtful anticoagulation, adjustment of LVAD speed, and medication optimization to maintain hemodynamic support during pregnancy. Hemodynamic changes during pregnancy include increased cardiac output, heart rate, and plasma volume, as well as decreased systemic vascular resistance, which can impact LVAD support. Despite reduced pulsatility in LVAD-supported patients, ovulation and reproductive capacity might be preserved, and viable pregnancies may be achieved with appropriate management. The review provides insights into the risks and considerations for a viable pregnancy during LVAD support, including the need for ongoing research to inform joined decision-making.

Organ Donation and Transplantation among Non-US Citizens: Opportunities to Improve Global Equity in Heart Transplantation.

BACKGROUND: Non-US citizens/non-US residents (NCNR) are a unique and growing population. Patterns of heart donation and heart transplantation (HT) within this subgroup have not been described fully. The purpose of this study was to evaluate the use of organs from NCNR donors and the characteristics and outcomes of NCNR HT recipients. METHODS: All adult donors whose hearts were recovered for HT and all primary adult HT recipients from 2013 to 2020 were identified using the United Network for Organ Sharing. Donors and recipients were categorized as citizens, residents, or NCNR. NCNR were further categorized by reason for travel to the United States. Outcomes included mortality, infection, and rejection at 1-year after transplantation. RESULTS: NCNR accounted for 0.4% (n = 77) of heart donors. Most NCNR donors identified as Hispanic (61%), were predominately recovered from the South and Southwest United States, and were less likely to express written documentation to be a donor compared with citizens and residents. NCNR accounted for 0.7% (n = 147) of all HT recipients. The majority identified as non-Hispanic White individuals (57.1%). Compared with citizens and residents, NCNR recipients seemed to be sicker, as evidenced by higher intra-aortic balloon pump use before HT and higher priority United Network for Organ Sharing status. Of NCNR recipients, 63% traveled to the United States for HT, predominately from Kuwait (29.9%) and Saudi Arabia (20%). At 1-year after transplant, there were no differences in mortality, infection, or rejection between the groups. CONCLUSIONS: A growing subgroup of NCNR travel from countries with low HT rates to the United States for HT. This finding highlights the need for strategies to improve equitable access to HT domestically and abroad.

Combined heart and liver transplantation in a patient supported by left ventricular assist device (LVAD) with propionic acidemia.

Propionic acidemia (PA) is a rare inherited metabolic disease due to inborn errors of metabolism. PA results in the accumulation of abnormal organic acid metabolites in multiple systems, mainly the central nervous system and the heart. Cardiac complications include dilated cardiomyopathy (DCM) and carry a 40-50% increased mortality risk. Liver transplantation (LT) is required in PA patients when medical treatment fails and may prevent or slow down the cardiomyopathy progression. However, severe heart disease may be a serious contraindication to LT. We present a complicated case of a PA patient, supported with a Left Ventricular Assist Device, who underwent a heart and Liver transplant. PA patients are at increased risk for metabolic acidosis during surgery, with increased anion gap and hyperammonemia. A strict multi-disciplinary approach is needed to prevent and treat metabolic decompensation. The patient had a successful heart and liver transplant after a strict treatment protocol in the pre, intra, and post-operative periods. His case highlights the complexity of PA patients and the increased risk for metabolic decompensation during surgery and provides an insight into how to manage such complicated patients.

Enhanced socket preparation during autotransplantation: a new treatment protocol.

OBJECTIVE: Tooth autotransplantation (AT) is a viable option for the replacement of unrestorable or missing teeth. Recently, the use of a 3D replica of a donor tooth constructed from CBCT scans was described. The model is made to assess the recipient site's size and minimize the required extraoral time of the donor tooth after extraction. The aim of the paper was to describe a new technique for AT using the 3D replica as a socket preparation tool. CASE REPORT: A 13-year-old boy who presented with hypodontia was referred for consultation and treatment. The treatment plan included combined orthodontic treatment and AT of the mandibular left second premolar into the site of the congenitally missing maxillary right canine. A titanium 3D model of the donor tooth was printed by a direct metal laser 3D printer utilizing the model from the CBCT scan. An intrasulcular flap was elevated, and the edentulous maxillary ridge was prepared using implant trephine burs with increasing diameters. A surgical mallet was utilized to apply vertical forces to the 3D-printed model, which was inserted into the prepared socket to allow a perfect fit for the donor tooth. After atraumatic extraction of the mandibular left second premolar, the donor tooth was inserted into the ready socket and splinted. Follow-up examinations at 1, 3, and 6 months, and 1 year after surgery demonstrated a successful outcome. CONCLUSION: The titanium replica was successfully used for precise preparation of the recipient site, minimizing the extraoral time of the procedure to 4 minutes, and thereby improving the expected outcome. (Quintessence Int 2023;54:142-148; doi: 10.3290/j.qi.b3649031).

Expanding the Surgeon's Armamentarium: Use of the Tubing Technique to Preserve the Inferior Alveolar Nerve During Transposition Procedure.

Severe edentulous posterior mandible atrophy with inadequate bone height superior to the inferior alveolar canal may increase the risk of neurosensory impairment and other complications during inferior alveolar nerve (IAN) transposition (IANT) prior to dental implant insertion. The current report describes the tubing technique as a practical and feasible procedure that ensures IAN preservation during IANT. The technique involves wrapping a standard suction catheter around the exposed nerve to facilitate full coverage. This work presents a retrospective review of 31 patients undergoing IANT procedures followed by immediate placement of dental implants between January 2015 and January 2020. IANT was performed either unilaterally or bilaterally on all patients, followed by IAN tubing before implant placement. A total of 46 IANT procedures involving the tubing technique were performed. Overall, 149 dental implants were inserted during IANT surgeries, with a success rate of 98.6%. Sensory disturbance was documented in 47.8% of the treated sites (left/right mandible) at 1 month (22/46 sites), 21.7% at 3 months (10/46 sites), 6.5% at 6 months (3/46 sites), and 2.2% at 12 months (1/46 sites) postimplantation. In total, except for 1 case, sensory disturbance was fully resolved by the end of the 12-month follow-up period. Taken together, the tubing technique described herein is a practical and reproducible method for protecting the IAN during transposition.

Prevalence and clinical implication of thrombocytopenia and heparin-induced thrombocytopenia in patients who are critically ill with COVID-19.

As the COVID-19 pandemic continues to evolve, different clinical manifestations are better understood and studied. These include various haematologic disorders that have been shown to be associated with increased morbidity and mortality. We studied the prevalence of one unusual manifestation, heparin-induced thrombocytopenia (HIT) and its clinical implications in patients who are severely ill with COVID-19 in a single tertiary centre in Israel. The presence of thrombocytopenia, disseminated intravascular coagulation (DIC) and HIT, and their association with clinical course and outcomes were studied. One-hundred and seven patients with COVID-19 were included. Fifty-seven (53.2%) patients developed thrombocytopenia, which was associated with the worst outcomes (ventilation, DIC and increased mortality). Sixteen (28.0%) patients with thrombocytopenia were positive for HIT, all of which were supported by extracorporeal devices. HIT was independently associated with ventilation days, blood product transfusions, longer hospitalisation and mortality.Platelet abnormalities and HIT are common in patients who are critically ill with COVID-19 and are associated with the worst clinical outcomes. The mechanisms underlying HIT in COVID-19 are yet to be studied; HIT may contribute to the dysregulated immunologic response associated with COVID-19 critical illness and may play a significant part in the coagulopathy seen in these patients. As many patients with COVID-19 require aggressive thromboprophylaxis, further understanding of HIT and the implementation of appropriate protocols are important.