The development of the upper extremity begins early in embryogenesis, with the upper extremity fully formed by week 8 of gestation. This process relies on a complex cascade of molecular interactions-a single abnormality of which can result in congenital anomalies. Hand surgeons have the opportunity to significantly improve the quality of life of patients with congenital anomalies and require a thorough understanding of the underlying embryological processes resulting in these anomalies. This chapter provides an overview of the stages of upper extremity development, the molecular mechanisms of upper extremity embryogenesis, and the congenital anomalies that can result from abnormalities of various stages of this process.
Constriction band syndrome is a rare congenital deformity that occurs in 0.5 to 1.1 per 10,000 births and presents as a range of malformations from constriction bands to autoamputation. The etiology of constriction band syndrome is incompletely understood, but the leading theory suggests that partial rupture of the inner amnion prior to fusion with the outer chorion creates fibrous chorionic bands that constrict fetal parts. Given the heterogeneity of malformations, a comprehensive physical examination is essential for accurate diagnosis. Depending on the severity of the constriction band, surgical intervention can range from simple excision of constriction bands to on-top-plasties in cases of digit deficiencies. Importantly, each patient should receive an individualized approach based on their anatomy, which considers the urgency of constriction band release, preservation of the neurovascular structures, viability of the distal body part, and maximization of functionality. With these goals in mind, surgical management of constriction band syndrome regardless of presentation can greatly improve function and cosmesis in affected children.
Syndactyly is a common congenital limb malformation caused by failure of formation or differentiation of an unspecified axis of the hand plate. Syndactyly has a wide range of phenotypes and is classified based on the structures involved, the length of the digit involved, and whether it occurs in isolation or within the setting of a syndrome. Surgery is the mainstay of treatment with the primary goal of restoring form and function by creating an adequate web space and providing sufficient skin coverage after digit separation. Skin flaps with or without the use of skin grafts are the primary techniques utilized for syndactyly repair with a multitude of skin flap designs described in the literature. This chapter provides an overview of the etiology, classification, and management of syndactyly, including surgical techniques, special considerations, outcomes, and long-term management.
The thumb accounts for approximately 40% of overall hand function, and deformities carry significant implications for pediatric hand development and quality of life. This article reviews three distinct congenital and acquired thumb deformities: pediatric trigger thumb, triphalangeal thumb, and congenital clasped thumb. Pediatric trigger thumb, an acquired condition resulting from a size mismatch between the flexor pollicis longus tendon and the A1 pulley, is staged using the Sugimoto classification and can resolve spontaneously, though surgical release of the A1 pulley reliably restores full range of motion in refractory cases. Triphalangeal thumb presents across a wide spectrum from a single extra phalanx to a five-fingered hand with absent thenar musculature and is classified by the morphology of the extra phalanx to guide surgical reconstruction. Congenital clasped thumb, a flexion-adduction deformity caused by hypoplasia or absence of the thumb extensors, can be categorized by either Tsuyuguchi's system or Mih's modification of McCarroll's system and managed initially with splinting. Surgical reconstruction is reserved for resistant or complex cases. Accurate diagnosis and classification of each condition are essential, as the natural history, associated systemic anomalies, and response to conservative versus operative intervention differ considerably across deformities.
Abstract Spring cranioplasty, originally developed for sagittal synostosis, has expanded to address selected lambdoid and coronal deformities by applying continuous mechanical distraction to gradually expand the cranium while avoiding the extensive dissection required for open vault remodeling. This chapter reviews the rationale, surgical technique, and outcomes of spring-mediated correction for these indications. For unilambdoid synostosis, comparative data show shorter operative times and lower blood loss relative to cranial vault reconstruction. For coronal synostosis, spring-assisted approaches offer reduced operative morbidity relative to fronto-orbital advancement, although limited control over final orbital position remains a notable trade-off. In both indications, a required second surgery for spring removal remains an inherent limitation. Our institutional experience, including virtual surgical planning to optimize spring placement and vector control, is presented alongside illustrative cases. As evidence for these non-sagittal applications continues to grow, larger comparative studies are needed to better define indications, refine surgical technique, and evaluate long-term outcomes.
Polydactyly of the hand is among the most common congenital anomalies of the upper extremity and encompasses a broad range of anatomic and functional presentations. It is characterized by a duplicated digit, which may occur as an isolated finding or in association with genetic syndromes. Based on the location and characteristics of the duplication, polydactyly is commonly classified as preaxial, postaxial, or central. Proper evaluation requires an understanding of limb embryology, genetic influences, and classification systems, as these factors directly inform surgical planning. Treatment strategies can range from simple excision of rudimentary digits to complex reconstruction aimed at restoring stability, alignment, mobility, and appearance. This chapter focuses on hand polydactyly, reviewing its embryologic and genetic foundations, classification systems, and approaches to surgical management. Emphasis is placed on technique selection, timing of intervention, and considerations that influence functional and aesthetic outcomes.
Congenital deformities of the digits can greatly impact hand function, aesthetics, and psychosocial well-being. Given the hand's crucial role in fine motor activity and social interaction, even subtle abnormalities can prompt clinical evaluation. This chapter provides a comprehensive overview of five congenital digit deformities (camptodactyly, clinodactyly, brachydactyly, macrodactyly, and symphalangism), with emphasis on their clinical presentation, underlying etiologies, diagnostic evaluation, and management strategies.
Congenital forearm and wrist deformities, including Madelung's deformity, congenital radial head dislocation, and proximal radioulnar synostosis, present reconstructive challenges for upper extremity surgeons. While etiologically distinct, these developmental anomalies disrupt forearm rotation, elbow stability, and aesthetic appearance. This review examines the natural histories and management strategies necessary to restore form and function in pediatric patients. Madelung's deformity, characterized by distal radial physeal growth arrest and a tethering Vickers ligament, requires corrective osteotomies to address progressive pain and deformity. Congenital radial head dislocation necessitates radiographic evaluation to distinguish it from acquired trauma and is managed conservatively. Proximal radioulnar synostosis causes functional restrictions requiring derotational osteotomies in symptomatic patients. Precise anatomical understanding and individualized clinical judgment are essential to restore joint kinematics.
Cerebrovascular revascularization for moyamoya disease remains one of the most technically demanding procedures in neurosurgery, requiring meticulous microvascular anastomosis and precise intraoperative execution. The success of these operations depends on advanced microsurgical skill, careful teamwork, and refined perioperative planning. This review outlines the emerging neuroplastic approach-a collaborative model between neurosurgeons and plastic microsurgeons-and its integration with augmented reality (AR) technologies to enhance surgical precision, planning, and education. Drawing on recent evidence, neuroplastic collaboration improves graft patency, reduces ischemic complications, and shortens hospital stay in moyamoya revascularization. Parallel advances in AR enable immersive three-dimensional visualization, microvascular simulation, and intraoperative guidance. The combined neuroplastic-AR workflow enhances surgical accuracy, training efficiency, and patient safety, offering a sustainable framework for the next generation of cerebral revascularization.
This presentation highlights a series of challenging reconstructive microsurgery cases encountered over the past 45 years. Selected cases from a collection of 500 unusual scenarios demonstrate innovative techniques developed to address complex reconstructive problems, aiming to stimulate discussion and further advancements in the field. These include refinements in microvascular anastomosis, novel approaches to esophageal reconstruction, treatment for intractable chylous ascites, techniques for small vessel anastomosis, solutions for vessel-depleted necks, and strategies for managing complications.
Abdominal wall defects (AWDs) represent a significant reconstructive challenge, necessitating restoration of both structural integrity and dynamic function. While static reconstruction can address structural deficits, it often fails to replicate the dynamic properties of the native abdominal wall musculature, potentially resulting in compromised core strength and increased hernia recurrence. This article reviews the principles and techniques of dynamic abdominal wall reconstruction utilizing innervated muscle transfer, emphasizing its advantages in restoring core strength, minimizing hernia recurrence, and improving overall functional outcomes, particularly in complex cases. We will outline surgical planning, donor site selection, operative techniques, and reported clinical outcomes.
Conventional microsurgical flap dissection courses typically utilize whole-body cadavers and emphasize the advantage of exposing participants to a greater number of flap dissections within a single course. However, we hold a different perspective. Although this viewpoint has been expressed in various courses and academic forums, it has not generated substantial discussion or adoption. We believe the issue is largely conceptual and psychological. Many participants appear to embrace the notion that "the more flaps learned, the better," and course organizers often respond accordingly by promoting the opportunity to learn as many flaps as possible in one setting. In reality, this approach may overlook a fundamental principle: the essence of microsurgical flap training lies in mastering the core techniques of flap dissection-skills that are transferable across virtually all flap harvest procedures. With this philosophy in mind, the Chang Gung Microsurgery Center initiated an annual cadaveric dissection course using isolated lower extremity specimens soon after the establishment of the hospital's skill laboratory and dedicated cadaveric dissection facilities. In this narrative review, we describe the conceptual framework derived from our high clinical case volume and long-standing surgical education philosophy, together with our unique institutional experience and resources. The curriculum focuses primarily on three "mother" flaps that serve as both technical foundations and clinical workhorses-the anterolateral thigh flap, the fibular osteoseptocutaneous flap, and the toe flap-supplemented by other flaps that can be harvested from the lower extremity. We also discuss the transferability of these techniques to other reconstructive applications. Furthermore, we outline how our institution's distinctive resources are integrated to provide participants with a comprehensive understanding of microsurgical practice. The advantages of this lower extremity-focused training model-including improved learning efficiency and reduced financial and administrative burdens for both organizers and participants-are examined. We hope this model may serve as a valuable reference for medical centers currently engaged in, or planning to develop, microsurgical education and training programs.
For over four decades, Chang Gung Memorial Hospital has maintained a dedicated microsurgical intensive care unit (MICU). This article explicates the role of this specialized unit within this high-volume center characterized by significant surgical complexity, examines its necessity, and offers insights for international colleagues. Established in the early 1980s during Taiwan's rapid industrialization to address severe limb trauma in a young workforce, the unit has evolved to support an increasing volume of complex head and neck, breast, lymphedema, and peripheral nerve reconstruction. Although global trends favor ward-based care, the MICU remains essential within our hospital context to ensure optimal patient care that individual surgical specialties strive for. Alongside clinical outcomes, the unit also aims to reduce the surgeons' postoperative burden, thereby enhancing surgical efficacy and laying the foundation for continued academic pursuit through centralized, comprehensive data collection for all microsurgical cases of the center. We present this model not as a universal advocacy, but as a reference for medical centers in regions with healthcare systems similar to Taiwan, especially those with comparable microsurgical volumes, varieties, and levels of complexity.
The rapid evolution of digital communication has transformed medical education, a shift accelerated by the COVID-19 pandemic. The International Microsurgery Club (IMC), founded in 2016 as a private Facebook group for verified professionals, exemplifies how social media can democratize microsurgical education on a global scale. By the end of 2025, IMC Facebook group had grown to over 22,600 members from more than 70 countries, facilitating case sharing, peer consultation, and professional recognition beyond geographic and institutional boundaries. Analysis of IMC activity between 2019 and 2025 identified 2,124 unique case-related posts contributed by 526 authors, with wide geographic diversity and high engagement independent of posting frequency. During the pandemic, IMC expanded into a sustained weekly webinar series, delivering nearly 600 sessions featuring international experts. Complemented by an open-access journal, a digital educational Web site, and multi-platform social media integration, IMC has evolved into a comprehensive, sustainable ecosystem for global microsurgical education, offering an effective model that complements traditional academic pathways.
Nasal reconstruction, involving a central facial structure with complex three-dimensional contours and essential respiratory function, continues to evolve. The principal challenge lies in simultaneous restoration of the three essential components-external skin cover, skeletal support, and a vascularized internal lining-often across multiple aesthetic subunits. This review summarizes a decade of clinical experience at Chang Gung Memorial Hospital, focusing on the evolution of reconstructive strategies in 150 patients with total or subtotal composite nasal defects. Particular emphasis is placed on the incorporation of microsurgical free flaps to enhance both aesthetic outcomes and reconstructive efficiency. This chronologically structured review highlights four major advances: (1) refinements of the paramedian forehead flap (PFF), including a T-shaped design for improved biomechanical stabilization in columellar reconstruction; (2) application of vascularized lining using the folded ulnar forearm flap (FUFF) and lower-extremity free flaps, including the anterolateral thigh (ALT) and medial sural artery perforator (MSAP) flaps; (3) integration of digital technologies, including computer-aided design (CAD) and three-dimensional printing, to improve nasal symmetry; and (4) implementation of an expedited protocol involving simultaneous free flap and PFF transfer to facilitate physical and psychosocial recovery. The T-shaped PFF design demonstrated superiority in preventing columellar dehiscence. For internal lining, the FUFF provided thin and pliable coverage with minimal donor-site morbidity; however, lower-extremity flaps (ALT/MSAP) offered enhanced long-term passive structural support, reducing the risk of airway collapse. Digital planning with three-dimensionally printed templates resulted in significantly improved postoperative symmetry in heminasal reconstructions ( p < 0.05). Simultaneous free flap and PFF transfer proved safe and significantly shortened overall treatment duration. Psychosocial assessments revealed a reduced duration of postoperative distress, underscoring the clinical importance of procedural efficiency. Successful contemporary reconstruction of complex nasal defects requires a specialized, multimodal approach. Optimal long-term aesthetic and functional outcomes are achieved through the synergistic application of refined PFF techniques, appropriate selection of vascularized lining free flaps, and routine use of digital technologies for surgical planning.
Reconstructive microsurgery is central to contemporary reconstructive surgery, enabling complex restoration of form and function across multiple anatomical regions. As clinical demands increase and operative exposure declines, the need for effective, structured microsurgical training has become more pressing. Despite advances in simulation, assessment, and curriculum design, substantial variability persists in how microsurgical training is delivered, validated, and sustained worldwide. This narrative review synthesizes the current global landscape of microsurgical training, examining key challenges and evidence-based educational strategies. Core components of effective training programs are identified, including technical skills acquisition, objective assessment, theoretical knowledge, research engagement, structured training pathways, and mentorship. A high-volume, longitudinal training model at Chang Gung Memorial Hospital is presented as an illustrative example. Future directions in microsurgical education are explored, with particular emphasis on competency-based curricula and entrustable professional activities. Key challenges include global variability and inequity in training access, limited longitudinal validation of training outcomes, reduced operative exposure, overemphasis on isolated technical skills, and shortages in mentorship capacity. Effective microsurgical training requires integration of technical, cognitive, non-technical, and professional competencies within longitudinal, context-rich educational frameworks. Emerging approaches-including distributed simulation, advanced virtual reality technologies, structured supervision, and international training networks-offer potential solutions to current limitations. Microsurgical education must evolve beyond episodic technical training toward integrated, competency-based frameworks that support progressive autonomy, patient safety, and independent practice. Although no single model is universally replicable, transferable principles from established programs can inform curriculum design across diverse settings. Continued investment in trainer development, outcome-driven educational research, and international collaboration will be essential to ensure the sustainability, equity, and effectiveness of future microsurgical training.
The free-style flap, based on the principles of "angiosomes" and evolved through the refinement of "perforator flaps," allows for safe harvest once a sizable cutaneous vessel is reliably identified. This approach resolves concerns regarding anatomical inconsistencies in conventional harvests. Successful execution relies on preoperative Doppler mapping or imaging studies, intricate flap design, and meticulous retrograde intramuscular dissection to address technical challenges when unforeseen vascular anatomy is encountered in commonly used flaps or unfamiliar donor sites. Free-style flaps can be employed as either locoregional or free flap transfers, while similar techniques allow for the reuse of previously transferred tissues. Such an approach substantially broadens the options for donor site selection, ensuring precise color and texture matching. However, it requires strict patient selection, flexible intraoperative adjustments, and multiple backup plans to ensure reconstructive success. If strategically employed, free-style flaps serve as a versatile alternative in challenging clinical scenarios.
Liver transplantation (LT) is an accepted curative therapy to save select patients with end-stage liver failure, congenital liver diseases affecting the liver or bile duct, and hepatocellular carcinoma. Living donor liver transplantation is an indispensable and alternative choice to manage the scarcity of deceased liver grafts and to provide a quick way to access a healthy graft. Successful hepatic artery reconstruction for liver transplantation is crucial for outcomes. Difficult hepatic artery reconstructions (HAR) are not uncommon in LT, especially in living donor liver transplantation (LDLT). They are defined as graft or recipient hepatic arteries smaller than 2 mm in diameter, size discrepancy greater than 2 to 1, and also include cases with multiple hepatic arteries, suboptimal quality, or those that require immediate redo HAR during transplantation. Technique refinements include selection of the appropriate recipient HA, precise HA dissection, early recognition of vessel injury under the microscope, meticulous use of clips for branch ligations whenever needed, deliberate oblique cut of the artery, and the use of a modified funneling technique, or shifting to an alternative artery to replace a pathologic HA. Reconstruction of an additional HA for dual arterial supply can also contribute to the improved result and minimize complications. Complex biliary anatomies are also commonly encountered in living donor liver transplantation. Reconstruction using microsurgical techniques and specific surgical strategies can lead to a significant reduction of biliary complications, as seen in our experience from an average of 10.35% between 2006 and 2021, to 6.5% in the year 2022. These techniques and approaches include using the ipsilateral bile duct as the first choice for duct anastomosis, an additional figure-of-8 suture over the anastomosis site, centralization of duct anastomosis when size discrepancy is greater than 2 to 1, and thoughtful selective biliary stent insertion in select cases. In conclusion, the application of microsurgical techniques and refined surgical strategies has tremendously improved the results of hepatic artery and biliary reconstructions in living donor liver transplantation, leading to lower complication rates and better outcomes.
