A varicocele is an abnormal dilation of the veins within the testicular pampiniform plexus. Varicoceles can be found in approximately 15 percent of the general male population and are more prevalent in men presenting with subfertility or infertility [1, 2]. Forty percent of men being evaluated for infertility may be found to have a varicocele, and varicoceles have been implicated in as many as 80 percent of men presenting with secondary infertility [2, 3]. In fact, varicoceles remain the most common reversible cause of male infertility [4]. Additionally, the inheritance of varicoceles may be genetically linked, as 56 percent of men with a first-degree relative diagnosed with a known varicocele will also have a varicocele, independent of varicocele grade or laterality [5]. With the large variability in varicocele phenotype, biomarkers to predict the development and clinical outcomes of a varicocele do not yet currently exist. However, with the advent of next-generation sequencing, studies are being conducted to identify the genetic and epigenetic changes associated with varicoceles in hopes of early detection and treatment of patients who may benefit from varicocele intervention [6].

Over the past 40 years, the trend has been to perform more complex, corrective and fewer palliative procedures on younger and smaller patients. Today, more than 50% of pediatric open-heart operations are performed in infants less than one year of age with more than 20% of all pediatric heart procedures performed during the first month of life. The outcomes following surgery for congenital heart disease have improved significantly in recent decades, which is in part due to advances made in our understanding and techniques of cardiopulmonary bypass (CPB).Pediatric perfusionists must have specialized knowledge related to pediatric physiology and congenital heart disease as well as the ability to utilize perfusion circuits adapted to a wide range of patient sizes. Pediatric perfusion cases can sometimes be very long due to the complexity of the cardiac repairs.

There is an increasing recognition that non-technical skills, such as teamwork, communication and interpersonal competencies, provide the foundation of any cardiac surgery program.Understanding the human and psychological factors at play can help teams make the transition from good patient care to excellent patient care. This chapter will focus on those human, environmental and cultural factors that can be leveraged to optimize team performance with a focus on perfusion practice.

Cardiopulmonary bypass (CPB) is highly technical and complex and accident and error can occur due to malfunction of equipment and/or human factors.Since its first successful clinical use in 1953, incremental improvements in the heart lung machine have resulted in a decline of perfusion related accidents. Safety practices have been demonstrated to reduce the incidence of error and equipment fault and need to be constantly reviewed and their implementation should be regularly rehearsed by all members of the intraoperative team and not only by the perfusion team. Institutional protocols, compliance with instructions for use of equipment and step-by-step processes to deal with error and unforeseen events will minimize their impact.

Cardiopulmonary bypass (CPB) provides optimum conditions for cardiothoracic surgery by combining a pump to substitute for the function of the heart and a gas exchange device, the “oxygenator,” to act as an artificial lung. CPB therefore allows heart and lungs to be temporarily suspended to facilitate cardiac, vascular or thoracic surgery in a safe, still, bloodless and controlled environment. This chapter provides an overview over the constituent components of a working bypass circuit.

Both cardiopulmonary bypass (CPB) and extra-corporeal membrane oxygenation (ECMO) are forms of mechanical circulatory support (MCS) utilized for short or long-term supplementation of native cardiac and/or respiratory function. The indications for these specialist techniques are becoming increasingly broad as treated pathologies get more complex. This chapter addresses complex MCS techniques during cardiothoracic surgery, specialist techniques utilized during donor organ procurement and during heart, lung and liver transplantation as well as emergent uses of MCS both inside and outside the operating room.

CPB as well as surgical trauma have a significant impact on the usually well-balanced coagulation system. This often leads to bleeding complications, and interventions to restore this balance are frequently attempted perioperatively. The coagulation and inflammatory systems are so complex that restoration of homeostatic balance cannot be achieved by giving blood products alone. Major known causes of CPB associated coagulopathy are dilution, complex and variable platelet dysfunction, fibrinolysis, the effects of heparin and protamine, hypocalcemia, hypothermia, as well as activation of the coagulation system after contact with artificial surfaces and from tissue factor release from the endothelium in response to ischemia and reperfusion.

The evolution of CPB has been marked on one side by sophistication and complexity and on the other side by an increased requirement for safety. The medical communities in many countries have issued recommendations concerning the training of clinical perfusionists and the use of monitoring and safety devices for CPB. Assembling the cardiopulmonary bypass (CPB) circuit and checking the heart lung machine (HLM) for faults prior to clinical use is an essential and integral part of the provision of clinical perfusion.

A fundamental area of responsibility for the perfusionist during cardiopulmonary bypass is to monitor, respond to and document heart lung machine parameters as well as physiological variables obtained from the anesthetic monitor and other physiological monitoring devices.This chapter summarizes the monitoring recommendations such as the 2019 EACTS/EACTA/EBCP guidelines on cardiopulmonary bypass in adult cardiac surgery or the combined recommendations of the Society of Clinical Perfusion Scientists of Great Britain and Ireland for Standards of Monitoring and Safety during CPB and the American Society of ExtraCorporeal Technology Standards and Guidelines for Perfusion Practice and shows how to apply them in daily practice.

The transition from physiological circulation to cardiopulmonary bypass (CPB) represents a major change to the homeostasis of the body including alterations in the distribution of blood flow and oxygen delivery to organs, which may at least in part account for the organ dysfunction during CPB. Layered on top of disturbances in oxygen delivery is a systemic inflammatory response triggered by contact of leukocytes and other blood components with the artificial surfaces of the extracorporeal circuit. While most of these host responses are appropriate and desirable in the context of a localized injury or infection, they are not desirable systemically and contribute to the morbidity and mortality associated with cardiopulmonary bypass.

The metabolic management of patients on cardiopulmonary bypass (CPB) is a complex process, involving several key biochemical and physiological parameters essential to maintaining homeostasis and reducing morbidity and mortality associated with CPB and cardiac surgery.There is movement toward goal directed perfusion (GDP), using indexed parameters such as carbon dioxide production, oxygen delivery and oxygen consumption to individualize perfusion strategies. This chapter provides an overview of the fundamental principles surrounding the metabolic management of the patient on CPB.

Acute kidney injury is the most common major complication after cardiac surgery. The incidence of cardiac surgery-associated AKI (CSA-AKI) varies between 5% to 40% and leads to dramatically worse outcomes. The incidence of CSA-AKI requiring renal replacement therapyafter coronary artery bypass grafting alone is roughly 1%. After valve surgery or combined CABG plus valve surgery the risk of requiring RRT increases to 1.7 and 3.3% respectively.Regardless of its reversibility, CSA-AKI has been associated with increased mortality and risk of developing chronic or end-stage renal disease, and consequently generating substantial cost.

The goals of CPB are to provide a still and bloodless field for the surgeon to operate while not damaging the heart muscle.This chapter reviews the conduct of CPB starting with cannulation (arterial and venous), general management of both the mechanical and physiologic aspects of CPB and finishes with a section regarding important aspects of CPB related to minimally invasive cardiac surgery (MICS).It is important that each institution has detailed protocols and procedures for CPB, and many of the points discussed in this chapter will be performed within the construct of these protocols.

Avoiding unnecessary myocardial damage has been at the forefront of cardiac surgery since its early days. The ability to arrest and immobilize the heart and revive it again without loss of function has facilitated more and more complex surgeries. Effective myocardial protection, particularly for the duration of aortic cross clamping, involves multimodal strategies consisting of temperature management, cardioplegic solutions delivered by various routes as well as non-cardioplegic techniques like ischemic preconditioning through intermittent cross-clamping or pharmacological protection.

Minimal Invasive Extracorporeal Circulation’s (MiECC) unique characteristics include advances such as closed circuits with elimination of blood-air interaction, reduced hemodilution, biocompatible surfaces, and lack of scavenging and reinfusion of unprocessed shed blood. Contemporary hybrid (modular) systems allow perfusionists to safely employ MiECC in the full-spectrum cardiac surgery. MiECC provides the base for developing a multidisciplinary intraoperative strategy which encompasses a surgeon’s particular technique, goal-directed perfusion, as well as modified heparin/protamine management. As with traditional ECC techniques, MiECC requires close collaboration of surgical, anesthesiology and perfusion colleagues for optimal outcome.

The transition from cardiopulmonary bypass (CPB) to normal circulation requires numerous mechanical, physiological and pharmacological factors to be coordinated efficiently within a short period of time. Weaning from CPB is often a routine process, however preexisting poor cardiac function or difficulties during the operation may make it complex and challenging. Complications encountered during the weaning phase may contribute to significant additional perioperative morbidity.