Papers by Pradeep Kumar Radhakrishnan
GLOBAL JOURNAL OF RESEARCH ANALYSIS, 2025
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congeni... more Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital cardiac anomaly with potentially fatal outcomes if untreated. Traditional classications have emphasized infantile versus adult types or collateralization patterns. We propose a novel classication (RPKSAI CLASSIFICATION FOR ALCAPA) based on the precise origin within the pulmonary sinuses or commissures, which directly informs surgical repair. This scheme includes anterior, posterior, and commissural origins, as well as remote non-facing sinus variants, highlighting surgical feasibility for direct reimplantation, intrapulmonary tunneling, or ap-based reconstructions. The classication aims to guide surgical decision-making, reduce technical challenges, and improve outcomes.
Global challenges, May 27, 2020
flow choking is a compressible fluid flow effect caused by the blockage factor, developed in any ... more flow choking is a compressible fluid flow effect caused by the blockage factor, developed in any wall-bounded real-world fluid flow system, irrespective of the incoming flow velocity. The Sanal flow choking occurs at a critical pressure ratio (CPR) in any straight duct with the uniform cross-sectional area at the creeping inflow condition or at a low subsonic inflow condition when the total-to-static pressure ratio reaches the CPR, which is uniquely controlled by the heat capacity ratio (HCR) of the fluid. The Sanal flow choking can also occur in the streamtubes of both the internal and the external real-world fluid flows once the flow between the streamlines reaches the CPR. At this physical condition, if the streamtube shape in any reacting flow is similar to the convergent-divergent (CD) flow passage there are possibilities of the existence of the detonation anywhere in the divergent region of the off-designed CD nozzle-shaped streamtube. Note that at the Sanal flow choking condition the CPR is governed exclusively by the HCR of the incoming fluid. In the case of multispecies/composite fluid flows, the Sanal flow choking condition is detected by the lowest values of the HCR of the dominant base fluid or the nanofluid. The theoretical discovery of the phenomenon of the Sanal flow choking in the real-world fluid flow is a paradigm shift in the diagnostic sciences of the compressible fluid flows for a reliable verdict on various unanswered research topics of contemporary interest. The mathematical models capable to forecast the exact values of the blockage factor for both 2D and 3D fluid flow cases at the Sanal flow choking condition for adiabatic and diabatic fluid flow cases are critically reviewed herein. The beauty and novelty of these models stem from the veracity that at the Sanal flow choking condition for diabatic flows (flows that involve transfer of heat), all conservation laws of nature are satisfied at a unique sonic-fluidthroat location. The fact is that at the condition prescribed by the Sanal flow choking model for real-world fluid flows, the internal flow choking due to heating (thermal choking, -Rayleigh flow effect) and that of the frictional effects (Fanno flow effect ) converge at a unique location of the fluid-throat, where the Mach number reaches unity. Therefore, the exact value of the blockage factor predicted at the Sanal flow choking condition, corresponding to any fluid with the known HCR, could be taken as an infallible data worldwide for the certification, confirmation and standardization of various computational fluid dynamics (CFD) flow solvers authentically for meeting the future needs of various high fidelity multiphase and multispecies in silico simulations. This was an unresolved worldwide scientific problem for several decades. Though the basic governing equations of viscous flows were recognized for more than a century, until the theoretical discovery of the Sanal flow choking phenomenon, there was no closed-form analytical model available for predicting the 3D blockage factor of any internal flow system. It is well known that the available mathematical methods are incapable to solve analytically the entire governing equations for viscous flows with any laminar or turbulence model. The in silico solution of the developing nonlinear system of equations is a challenging numerical task in the CFD even with a desirable higher-order accuracy ensuring the strong and competent solution using a better-quality and super-fine grid systems. Such a robust and efficient solution is desirable or rather inevitable for solving V. R. Sanal Kumar is a professor of aeronautics and a rocket scientist affiliated with the Indian Space Research Organisation. He earned his Ph.D. in aerospace engineering from the Indian Institute of Science (IISc), Bangalore. He was an INSA-KOSEF postdoctoral fellow and a scientific ambassador to South Korea. He is leading the India-US joint research team on myocardial infarction in collaboration with AIIMS, New Delhi. He was a visiting professor in Japan and is currently working on an Indo-Russian project at IISc/KCT and pursuing collaborative research worldwide on multidisciplinary topics. He is a member of the American Heart Association and AIAA.
Research Square (Research Square), Mar 26, 2021
Although the interdisciplinary science of nanotechnology has been advanced significantly over the... more Although the interdisciplinary science of nanotechnology has been advanced significantly over the last few decades there were no closed-form analytical models to predict the three-dimensional (3D) boundary-layer-blockage (BLB) factor, of diabatic flows (flows involves the transfer of heat) passing through a nanoscale tube. As the pressure of the diabatic nanofluid and/or non-continuumflows rises, average-mean-free-path diminishes and thus, the Knudsen number lowers heading to a zero-slip wall-boundary condition with the compressible viscous flow regime in the nano scale tubes Nature 2 leading to Sanal flow choking [PMCID: PMC7267099; Physics of Fluids, DOI: 10.1063/5.0040440] creating a physical situation of the sonic-fluid-throat effect in the tube at a critical-total-to-static pressure ratio (CPR). Herein, we presented a closed-form-analytical-model, which is capable to predict exactly the 3D-BLB factor at the Sanal flow choking-condition of nanoscale diabatic fluid flow systems at the zero-slip-length. The innovation of Sanal flow choking model in the nanoscale fluid flow system is established herein through the entropy relation, as it satisfies all the conservation laws of nature. The exact value of the 3D-BLB factor in the sonic-fluidthroat region presented herein for each gas is a universal benchmark data for performing highfidelity in silico, in vitro and in vivo experiments for the lucrative design optimization of nanoscale fluid flow systems in gravity and microgravity environments and also for drug discovery for prohibiting asymptomatic cardiovascular diseases in Earth and human spaceflight <doi.org/10.2514/6.2021-0357>. Note that the relatively high and low-blood-viscosity (creating high turbulence) leads to the Sanal flow choking causing asymptomatic cardiovascular diseases. Such diseases in the cardiovascular system can be negated by maintaining the systolic-to-diastolic blood pressure ratio lower than the CPR <10.1002/gch2.202000076>. The CPR is regulated by the heat capacity ratio (HCR) of the fluid. Note that HCR is the key parameter, which could control simultaneously blood viscosity and turbulence. The physical insight of the boundary-layer-blockage persuaded nanoscale Sanal flow choking in diabatic flows presented in this article sheds light on finding solutions to numerous unresolved scientific problems in physical, chemical and biological systems carried forward over the centuries because the closed-form analytical model describing the phenomenon of Sanal flow choking is a unique scientific language of the real-world-fluid flows. More specifically, mathematical models presented herein are capable to forecast the limiting conditions of deflagration to detonation transition (DDT) in nanoscale systems and beyond with confidence. Additionally, the Sanal flow choking condition will forecast the asymptomatichemorrhage and acute-heart-failure . Briefly, the undesirable Sanal flow choking causing detonation and hemorrhagic stroke can be negated by increasing the HCR of the fluid.
International Journal of Cardiovascular and Thoracic Surgery, 2025
Accurate geometric modeling of the human heart is essential for understanding and simulating card... more Accurate geometric modeling of the human heart is essential for understanding and simulating cardiac fluid dynamics. Traditional left ventricular (LV) models-typically ellipsoidal, cylindrical, or conical-are limited in their ability to represent the complex regional structure and dynamic flow conditions present in a functioning heart. This study proposes an advanced geometric abstraction: the inverted octagonal pyramid model of the LV. This configuration introduces eight triangular faces converging at the apex, with an anatomically inspired octagonal base representing the mitral valve annulus, offering superior segmentation, mesh compatibility, and regional mechanical analysis. Using unsteady Navier-Stokes equations under physiological boundary conditions, this model captures systolic ejection mechanics including jet formation, vortex dynamics, wall shear stress (WSS) distribution, and flow separation zones. Quantitative simulation results across three scenarios-healthy heart, aortic stenosis, and hypertrophic cardiomyopathy (HCM)-reveal that the pyramid model predicts a Reynolds number (Re) range of 1200-5100 and vortex entropy index (VEI) values up to 0.6, indicating transitional-to-turbulent flow in diseased states. WSS distribution, especially near polygonal junctions, highlights zones of potential endocardial stress and thrombotic risk that conventional models fail to capture. This geometry is not only computationally robust for fluid-structure interaction (FSI) modeling but also aligns with echocardiographic segmental views, enhancing clinical relevance. Applications include patient-specific valve and stent design, surgical planning, CRT lead placement, and AI-based cardiac flow diagnostics. By more faithfully reflecting the true structural and flow heterogeneity of the heart, the inverted octagonal pyramid model establishes a new standard for integrative, biomechanical cardiovascular simulations. It bridges clinical imaging, computational modeling, and physiological accuracy-advancing both diagnostic precision and therapeutic planning in contemporary cardiology.
IntechOpen eBooks, Jul 28, 2021
Drawbacks persist relating to irreversibility of leaflet resection, time-consuming leaflet recons... more Drawbacks persist relating to irreversibility of leaflet resection, time-consuming leaflet reconstruction with sliding annuloplasty, monoleaflet function, and systolic anterior motion (SAM) risk. Graded neochordal reconstruction mitigates many of these but has the challenge of precise sizing and possibility of leaving excessive tissue, risking SAM. When this reconstruction is based on stress analysis and shear analysis methods the outcome gives the best results. Short term evaluation has been done with good outcomes.
EC Cardiology, Dec 23, 2019
Rotor vibration control during start-up, acceleration and deceleration phases are one of the key ... more Rotor vibration control during start-up, acceleration and deceleration phases are one of the key problems besides stable levitation, in high-speed applications of bearing less switched reluctance motor (BSRM) . Global sliding mode controller (GSMC) is proposed to control the speed and position of BSRM. Sensor less operation is achieved with sliding mode observer. Rotor displacement tracking error functions were used in the sliding mode switching functions. New sliding mode displacement control and speed tracking equations obtained using extra exponential fast decaying nonlinear function and conventional linear sliding mode switching. Simulation is carried on hybrid 12/14 BSRM with the proposed controller and observer. 12 stator poles and 14 rotor poles were selected. Pole arc was 25.71. FEM analysis showed Torque pole arc was 12.85. Air gap length was 0.25 -0.5 mm. Stator diameters -112/60.2, stator yoke thickness 7.7 mm, shaft diameter of 18 mm, coil width of 4 mm, rotor pole arc of 12.85, axial stack length of 40 mm, rotor yoke thickness of 9.7 mm-were the major design parameters. FEM of motor parameters under different loads for speed, torque load, switching angle, voltage, phase resistance and moment of inertia was performed. Separated single winding, wide suspending force region, higher power density, natural decoupling of torque from suspending force, low magnetic motive force, low core cost of hybrid 12/14 BSRM makes it ideal as motor for total artificial heart as destination therapy.
Design and Development of Miniature Slotted Impeller for Sai Spandan Total Artificial Heart for Destination Therapy
INTERNATIONAL JOURNAL OF SCIENTIFIC RESEARCH, Nov 1, 2021
In recent years, the use of rotary blood pumps (RBPs) as continuous ow VADs has surged ahead, an... more In recent years, the use of rotary blood pumps (RBPs) as continuous ow VADs has surged ahead, and virtually eliminated the use of pulsatile-ow or volume-displacement pumps for implantable, chronic mechanical circulatory support (MCS). Circuit Design modications like that in Saispandan has imparted pulsatility into RBP.Impeller designs are a signicant factor when designing centrifugal pumps as mechanical circulatory assist devices as smaller diameter impellers with higher rotational speeds to achieve target outputs would cause more blood component trauma compared to larger diameter impellers.Hydraulic performance and hemolysis tests in the same pump housing with different prototypes is needed. Ventricular assist parameters for efcient circulatory support would include an output of 5 L/min against 100 mmHg at speeds of 2500-3500 rpm. Vein height does not contribute signicantly to evaluation metric in most studies.
Destination Therapy with Drive Less Totalartificial Hearts
INTERNATIONAL JOURNAL OF SCIENTIFIC RESEARCH, May 1, 2022
Around 70% of mechanical circulatory devices nd application as bridge to transplantation and 30%... more Around 70% of mechanical circulatory devices nd application as bridge to transplantation and 30% as destination devices, but shortage of donor organs forces up to 85% of these to enter the zone of destination devices. There is an urgent need to do away with drive lines as they contribute signicantly to morbidity and mortality with device implantation. Hybrid coupled energy transfer system offer advantages of prolonged support and the redundancy of back up emergency support with retro auricular direct back up which is very essential when considering these devices on their role as destination therapy devices. Initial use has given promising results and devices that are emerging in the horizon like Saispandan would pave way for major technological advances in this eld. The power of prescribing a total articial heart as destination therapy would soon be a reality due to explosion of technology in multiple integrated disciplines.
Elective Mechanical Sub Pulmonary Support - the Final Frontier of Single Ventricle Palliation
GLOBAL JOURNAL FOR RESEARCH ANALYSIS, Sep 15, 2021
Sophisticated technology advances are fast taking taking shape to provide long term destination t... more Sophisticated technology advances are fast taking taking shape to provide long term destination therapy mechanical circulatory assistance. Sai Spandan total articial heart with hybrid BSRM core with dual motor and controls, virtual t technology is one such over the horizon. The promise is of better quality of life and longevity. Transcutaneous charging of fully implantable models would very soon revolutionize cardiac surgical treatment modalities. The nal frontier in a failing Fontan is sub pulmonary mechanical assistance. We take a short look into the issues and possibilities. The research gap exists for the innovator in this eld.
Design Development and Fabrication of an Atraumatic Rosai Bowel Protector/ Retractor
GLOBAL JOURNAL FOR RESEARCH ANALYSIS, Feb 15, 2021
Primary goal of this project was to design an effortless retractor for atraumatic bowel protectio... more Primary goal of this project was to design an effortless retractor for atraumatic bowel protection/retractor for deep pelvic surgeries with MRI assessment for normal human anatomical range of pelvic dimensions and bowel volume dimensions and AI enabled design
Optimized Centrifugal Pump Dimensions of Saispandan: Hybrid BSRM Total Artificial Heart for Destination Therapy
GLOBAL JOURNAL FOR RESEARCH ANALYSIS, Apr 15, 2021
Optimization of pump characteristics when supporting the mechanical functions of heart as destina... more Optimization of pump characteristics when supporting the mechanical functions of heart as destination therapy is essential because of limitations imposed on design on size and power. Computational uid dynamics assessment with uid bearing similar properties is done. Knowledge of previously designed similar pumps is an 5 added advantage. Pumps supporting heart operate in Reynolds numbers of 10 .Limited data is available on pumps that operate in this range. It is useful to present data using traditional Cordier diagram of nondimensional speed vs diameter. Flow, pressure and rotational speed are the main parametric analytic points. Similitude helps in efcient design concept.
Novel Operative Technique for Fully Implantable Total Artificial Hearts with Normal Cardiac Anatomy- Cadaveric Evaluation
INTERNATIONAL JOURNAL OF SCIENTIFIC RESEARCH
23 million people are affected by heart failure in the world. Even with the best promotional meth... more 23 million people are affected by heart failure in the world. Even with the best promotional methods there is a shortage of donor hearts globally. Advances in technology with development of fully implantable, durable, devices for mechanical support have strengthened the necessity of use of these devices for destination therapy. As better and novel prototypes emerge, the requirement of surgical innovations is a necessity for quick and safe implantation and explantation procedures in emergency. Use of augmented and virtual reality platforms for device patient match as well as surgical training is being looked into a serious option for such procedures in future.
Flexible Implantable Pediatric Total Artificial Hearts: The Future is Here
GLOBAL JOURNAL FOR RESEARCH ANALYSIS
In pediatric patients with congenital heart diseases need for ventricular assist devices adds on ... more In pediatric patients with congenital heart diseases need for ventricular assist devices adds on to risk score, especially in single ventricle situations. If technology provides with devices that could t into the available pericardial space without venous compression, total articial hearts would be the acceptable rst option in pediatric patients with indications for the same, the repertoire of which is continuously expanding with availability of smaller devices and emerging horizon of drive less articial hearts. Borderline situations can be very correctly evaluated using virtual t technologies. Of around 1000 TAH implants worldwide, less than 5% are pediatric, the volume of which would increase exponentially if exible implantable pumps with adequate hemodynamics emerge in the eld. Though initial applications centre on bridge to transplant, emerging technologies would make it feasible as destination therapy. Syncardia 50cc and evolving versions of Saispandan, based on hybrid b...
Design and Development of Miniature Slotted Impeller for Sai Spandan Total Artificial Heart for Destination Therapy
INTERNATIONAL JOURNAL OF SCIENTIFIC RESEARCH, 2021
In recent years, the use of rotary blood pumps (RBPs) as continuous ow VADs has surged ahead, an... more In recent years, the use of rotary blood pumps (RBPs) as continuous ow VADs has surged ahead, and virtually eliminated the use of pulsatile-ow or volume-displacement pumps for implantable, chronic mechanical circulatory support (MCS). Circuit Design modications like that in Saispandan has imparted pulsatility into RBP.Impeller designs are a signicant factor when designing centrifugal pumps as mechanical circulatory assist devices as smaller diameter impellers with higher rotational speeds to achieve target outputs would cause more blood component trauma compared to larger diameter impellers.Hydraulic performance and hemolysis tests in the same pump housing with different prototypes is needed. Ventricular assist parameters for efcient circulatory support would include an output of 5 L/min against 100 mmHg at speeds of 2500-3500 rpm. Vein height does not contribute signicantly to evaluation metric in most studies.
IJAR, 2025
The Half-Turned Truncal Switch Operation (HTTSO) represents an innovative surgical technique for ... more The Half-Turned Truncal Switch Operation (HTTSO) represents an innovative surgical technique for managing complex
congenital cardiac anomalies, particularly transposition of the great arteries (TGA) with associated ventricular septal
defect (VSD) and left ventricular outflow tract obstruction (LVOTO). This operation involves a 180-degree rotation of the truncal block to achieve
anatomical and physiological alignment of the ventriculo-arterial connection, thereby circumventing the need for prosthetic conduits. HTTSO
has emerged as a valuable alternative to traditional procedures such as the Rastelli, Nikaidoh, and arterial switch operations, particularly in
patients with challenging coronary artery anatomy or prior failed interventions. This review delineates the current indications, surgical technique,
contraindications, complications, follow-up protocol, and comparative efficacy of HTTSO, providing a comprehensive perspective on its utility
in modern congenital cardiac surgery. Emphasis is placed on surgical precision, long-term outcomes, and the evolving role of this technique in
biventricular repair strategies.
International Journal of Science and Research (IJSR), 2025
Cardiac development represents a pinnacle of vertebrate embryology, orchestrated through complex ... more Cardiac development represents a pinnacle of vertebrate embryology, orchestrated through complex genetic, molecular, and mechanical interactions. Recent advancements in developmental biology, tissue engineering, and gene regulation technologies have shed new light on the foundational processes of heart formation, particularly cardiac looping and chamber specification. A critical early morphogenetic event, dextral cardiac looping, converts a linear heart tube into a spatially structured organ. This transformation is regulated by left-right patterning genes such as Nodal and Pitx2, alongside biomechanical forces that introduce asymmetry into the growing tube. Simultaneously, cardiogenic transcription factors-NKX2-5, GATA4, ISL1, and TBX5-play pivotal roles in driving mesodermal cells toward cardiac lineages. With the advent of CRISPR-based gene editing, single-cell omics, and biofabrication platforms, it is now possible to manipulate these pathways to guide heart tissue formation in vitro. The convergence of developmental principles with tissue engineering has laid the groundwork for constructing autoengineered heart tissues, opening possibilities for personalized regenerative therapies. This review consolidates current insights into cardiac embryogenesis, gene regulation networks, and emerging technologies aimed at generating fully functional cardiac constructs.
The Annals of Thoracic Surgery, 2002
Background. Long-term follow-up of patients who underwent arterial switch operation for complete ... more Background. Long-term follow-up of patients who underwent arterial switch operation for complete transposition of great arteries with anatomic left ventricular outflow tract obstruction (LVOTO) has rarely been brought into the focus. Methods. Of 299 patients who underwent an arterial switch operation between January 1991 and January 2001, 23 patients had anatomic LVOTO. Age ranged from 4 days to 18 years (median 90 days) and weight ranged from 2.6 to 35 kg (median 4.3 kg). Surgical management included arterial switch operation, closure of ventricular septal defect wherever indicated, and excision of LVOTO. Results. Among patients with preoperative LVOTO there were 2 early deaths and 8 patients had mild neoaortic regurgitation at the time of discharge. Follow-up ranged from 8 months to 9 years (mean 60 ؎ 12 months). In 4 patients who had mild neoaortic regurgitation at discharge, the regurgitation progressed to moderate or severe degree after a follow-up of 22 to 72 months. In 1 patient mild mitral regurgitation present at the time of discharge progressed to severe mitral regurgitation. This patient subsequently underwent double valve replacement. Conclusions. Presence of preoperative anatomical LVOTO in patients undergoing arterial switch operation predicts high incidence of postoperative neoaortic regurgitation.
Indian Heart Journal, 2002
Background: Arterial level repair is considered the most appropriate procedure for transposition ... more Background: Arterial level repair is considered the most appropriate procedure for transposition of the great arteries. This report describes our experience with the arterial switch operation over the past decade. Methods and results: From January 1991 to January 2001, a total of 299 patients underwent an arterial switch operation for transposition of the great arteries or double-outlet right ventricle. Group I (n=169, 56.5%) comprised patients with transposition of the great arteries in whom the ventricular septum was essentially intact. Group II patients (n=130, 43.5%) had transposition of the great arteries with an additional significant ventricular septal defect or had double-outlet right ventricle with a subpulmonic ventricular septal defect. Of the total, 245 (82%) were males and 54 (18%) were females. In group I, the ages ranged from 2 days to 18 years (median 19 days) and weight ranged from 1.7 to 68 kg (median 2.5 kg). In group II, the ages ranged from 4 days to 4 years (median 90 days) and weight ranged from 2.5 to 17 kg (median 4 kg). Fifteen percent of the patients (25/169) in group I and 30% of the patients (39/130) in group II had features of bacteriologic infection. Arterial switch operation was performed on standard lines. In group I, 141 patients (83.4%) had a primary arterial switch operation while 28 (16.6%) underwent a rapid two-stage repair. Twenty-three patients required concomitant relief of associated anatomic left ventricular outflow tract obstruction. Operative mortality was 8.8% (15/169) in group I and 33% (44/130) in group II with an overall mortality of 19% (59/299). The major causes of operative mortality included pulmonary arterial hypertensive crisis (n=21), sepsis and related complications (n=16), and left ventricular failure (n=8). Coexisting arch anomalies, longer cross-clamp time, late presentation, and preoperative bacteriologic infections were incremental risk factors. Follow-up ranged from 1 to 10 years and was 87% complete. On follow-up, 91% of the patients were asymptomatic and off all medications. There were 3 late deaths and 5 patients required reoperation.
Virology & Mycology, 2021
A critical review has been carried out herein for correlating the phenomenon of internal flow cho... more A critical review has been carried out herein for correlating the phenomenon of internal flow choking (biofluid / Sanal flow choking (PMCID: PMC7267099)) and asymptomatic cardiovascular risk of COVID-19 patients. We show that when systolic-to-diastolic Blood-Pressure-Ratio (BPR) reaches the Lower-Critical-Hemorrhage-Index (LCHI) the internal flow choking could occur in the Cardiovascular System (CVS) with and without plaque/occlusion. The critical BPR for flow choking is uniquely regulating by the Biofluid/Blood-Heat-Capacity-Ratio (BHCR). The BHCR is well correlated with BPR, blood-viscosity and ejection-fraction. The closed-form analytical models reveal that the relatively high and the low blood-viscosity are Cardiovascular Risk (CVR) factors. In vitro data shows that nitrogen, oxygen, and carbon dioxide gases are predominant in fresh blood samples of the human being and Guinea-pig at a temperature range of 37-40 °C (98.6-104 F). In silico results demonstrated the occurrence of Sanalflow-choking at a critical BPR leading to shock wave generation and pressure-overshoot in CVS causing memory effect (stroke history). The asymptomatic cardiovascular-risk of COVID-19 patients and others could be diminished by concurrently lessening the viscosity of biofluid/blood and flow turbulence by increasing the thermal tolerance level in terms of BHCR and/or by decreasing the BPR.
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Papers by Pradeep Kumar Radhakrishnan
congenital cardiac anomalies, particularly transposition of the great arteries (TGA) with associated ventricular septal
defect (VSD) and left ventricular outflow tract obstruction (LVOTO). This operation involves a 180-degree rotation of the truncal block to achieve
anatomical and physiological alignment of the ventriculo-arterial connection, thereby circumventing the need for prosthetic conduits. HTTSO
has emerged as a valuable alternative to traditional procedures such as the Rastelli, Nikaidoh, and arterial switch operations, particularly in
patients with challenging coronary artery anatomy or prior failed interventions. This review delineates the current indications, surgical technique,
contraindications, complications, follow-up protocol, and comparative efficacy of HTTSO, providing a comprehensive perspective on its utility
in modern congenital cardiac surgery. Emphasis is placed on surgical precision, long-term outcomes, and the evolving role of this technique in
biventricular repair strategies.