Joon Pio Hong

Asan Medical Center | AMC · Department of Plastic Surgery

Wound healing is a central physiological process that restores the barrier properties of the skin after injury, comprising close coordination between several cell types (including fibroblasts and macrophages) in the wound bed. The complex mechanisms involved are executed and regulated by an equally complex, reciprocal signalling network involving n...

The relatively recent discovery of a novel lymphatic system within the brain meninges has spurred interest in how waste products generated by neurons and glial cells—including proteins associated with Alzheimer’s disease pathology such as Aβ and tau—are disposed of. Evidence is building that suggests disease progression in Alzheimer’s disease and o...

Optimal reconstruction of weight-bearing plantar foot defects is challenging due to the need for relatively thin coverage with simultaneous durability. The medial plantar flap provides an excellent tissue match but is not always available or appropriate (Figure 1, 2). Microsurgical free flap reconstruction provides many options for coverage. Howeve...

Lower extremity reconstruction still remains a challenge for several reasons, among which is the vascularity status of the limb with its direct implication on successful reconstruction. For that several modalities were described that are either diagnostic or, in some part, therapeutic to properly assess the vascularity status of the involved limb....

Over the years of reconstruction, the tools for diagnosis were limited for reconstructive microsurgeons. For decades, the main tools were the knowledge of anatomy, anecdotal experience, and most of all good judgment [1]. In the modern era, the angiogram and CT angiograms played a key role in providing critical information of the vascular status of...

Background This research aims to validate the proficiency and accuracy of the robotic microsurgery platform using rat femoral vessel model. Methods A total of 256 rat femoral vessels were performed, half using robotic and the other by manual microanastomosis by eight microsurgeons with less than 5 years of experience given eight trials (rats) each....

Background/Objectives: Recent advancements in breast cancer treatment have led to increased survival rates, prompting a shift towards addressing breast cancer-related lymphedema (BCRL). Despite the evolving role of lymphatic surgery in breast reconstruction, there is limited literature evaluating the current role of lymphatic surgery in breast reco...

Lymphedema is rare adverse effect of COVID-19 vaccination which was reported at several literatures. We present a case of surgically treated secondary lymphedema after the COVID-19 vaccination. The patient presented lymphedema at the upper extremity with no specific history except the COVID-19 vaccination 18 months before the visit. LVA and liposuc...

Vascularized lymph node transfer (VLNT) is an advanced surgical approach for secondary lymphedema (SLE) treatment, but tissue fibrosis around the lymph node flap (VLNF) inhibiting lymphangiogenesis is the biggest challenge undermining its therapeutic efficacy. This study explored the effects of periodic hyaluronidase (HLD) injection in reducing fib...

Background As the number of extremity amputations continues to rise, so does the demand for prosthetics. Emphasizing the importance of a nerve interface that effectively amplifies and transmits physiological signals through peripheral nerve surgery is crucial for achieving intuitive control. The regenerative peripheral nerve interface (RPNI) is rec...

In this chapter, relatively recent concept of “perforator-based flap” along with flaps emerging from this concept is reviewed by presenting the five landmark publication that have contributed to the evolution of modern flaps. Details are not given on individual techniques but rather discuss how these papers have shaped the direction of modern recon...

Despite the long existence of diabetes and its most dreaded complication, diabetic foot, the treatment for diabetic foot remains difficult. The multiple factors involved, and the wide spectrum of treatment makes it difficult for one surgeon to manage. Nevertheless, with a team approach, plastic surgeons can play a crucial role in managing the diabe...

Introduction Primary lymphedema is characterized by lymphatic dysplasia in which one variant is Milroy’s disease. The association with congenital chylothorax is even rarer with poor outcome. This is the first report to utilize peripheral lymphovenous anastomosis (LVA) and lymph node to vein anastomosis (LNVA) for the management of such condition....

Background Lipedema is a chronic, incurable disorder characterized by painful fat accumulation in the extremities. While the application of liposuction in lipedema management has become increasingly popular, the safety and effectiveness of this approach remain contentious. Our systematic review and meta-analysis aimed to assess various liposuction...

Background: Vascularized lymph node transfer (VLNT) is an innovative surgical technique used for the treatment of secondary lymphedema (SLE), an incurable disease resulting from impairment of the lymphatic system. The success of VLNT largely depends on lymphangiogenesis, the process of new lymphatic vessel formation. However, fibrosis around the tr...

Lateral ankle soft tissue defects pose challenges, especially in cases due to chronic pressure from cross-legged sitting, which usually present with a large dead space, small skin opening that often accompanies an open joint. Traditional reconstruction methods using fasciocutaneous flaps may result in donor site morbidity such as delayed wound heal...

Előrehaladott szájüregi daganatok eltávolítása után kialakult kiterjedt szövethiányok helyreállítására funkciómegtartó céllal a leggyakrabban alkalmazott eljárás a mikrovaszkuláris technikával végzett szabad szövetátültetés. Hazánkban a felületes szájüregi hiányok helyreállítására a leggyakrabban választott szabadlebeny a radiális alkarlebeny. Első...

Many young microsurgeons begin their careers at established hospitals where microsurgery resources are limited. This article shares the authors’ experiences in overcoming challenges and establishing a microsurgery practice in a new hospital. Due to the lack of equipment, limited support from colleagues, absence of discussion partners, fear of failu...

Microsurgery is a surgical approach or a specialty using surgical microscopes to manipulate small tissues such as vessels of the flap to reconstruct a defect caused by various reasons. Thus, it is the flap itself that facilitates the wound to heal. Flap reconstruction for wounds is frequently considered in cases of lacking healing progress despite...

Inflammation after surgical incisions is related to the degree of tissue damage. Healing with low inflammation is desirable, especially in patients with compromised healing potential. This experimental study was conducted to assess the degree of inflammatory reaction and scar formation from incisions made by an ultra-polished scalpel (UPS). Two par...

Background Lymph nodes may play a potential role in lymphedema surgery. Radiologic evaluation of nodes may reveal the status of pathologic conditions but with limited accuracy. This study is the first to evaluate the efficacy of ultrasound in detecting functioning nodes in lymphedema patients and presents a criterion for determining the functionali...

Diabetic foot ulcer represents the primary cause of hospital admissions, amputations, and mortality in diabetic patients. The development of diabetic foot ulcers is influenced by peripheral neuropathy, infection, and ischemia, with diabetes contributing to peripheral artery disease. Free tissue transfer combined with revascularisation of the lower...

Background This study aimed to quantify the blood flow of free flaps and compare the blood flow of small vessel (<0.8 mm) and larger vessel (>0.8 mm) anastomosed free flaps. Methods This retrospective study included patients treated successfully with a perforator free flap in the lower extremity between June 2015 and March 2017. A color duplex ultr...

Introduction Lower limb lymphedema (LLL) is a chronic condition that requires long-term treatment and affects quality of life by causing symptoms such as pain, heaviness, discomfort, and restriction of movement. And it is one of the common complications in patients undergoing gynecological cancer surgery including pelvic lymph node dissection (PLND...

Surface electromyography (sEMG) sensors play a critical role in diagnosing muscle conditions and enabling prosthetic device control, especially for lower extremity robotic legs. However, challenges arise when utilizing such sensors on residual limbs within a silicon liner worn by amputees, where dynamic pressure, narrow space, and perspiration can...

Intuitive and perceptual neuroprosthetic systems require a high degree of neural control and a variety of sensory feedback, but reliable neural interfaces for long‐term use that maintain their functionality are limited. Here, a novel hybrid bionic interface is presented, fabricated by integrating a biological interface (regenerative peripheral nerv...

Light-emitting diode (LED) lights produce a variety of wavelengths that have demonstrable efficacy in therapeutic and aesthetic fields. However, a repetitive treatment regimen is required to produce treatment outcomes, which has created a need for portable LED devices. In this study, we aimed to develop a portable therapeutic LED device and investi...

Introduction The functional and dilated lymphatic vessel and veins with minimal backflow and pressure are considered ideal for lymphaticovenous anastomsosis (LVA). However, how to select the ideal vein remains to be determined. This study aims to provide further insight in selecting the ideal vein. Material and Methods This is a retrospective stud...

The evolution is continuing in the field for diabetic foot reconstruction. The advent of supermicrosurgery and the other advanced techniques described in this chapter have expanded the possibilities for reconstruction and decreased the morbidity associated with traditional flap surgery. This chapter describes the use of these tools that has allowed...

Lymphatics vessel wall and lumen visualization during anastomosis process is quite challenging for which different techniques were described with variable efficacy. Double opposing color contrast is created using 10% Sodium Fluorescein (FS) which stains lymphatic fluid with yellow causing a clear contrast to blue marker painted lymphatic wall impro...

INTRODUCTION: Lipedema is a progressive connective tissue disease with enlargement of adipose tissue, fibrosis, fluid collection and dermal thickening. Herein, we present a case of lipedema associated with skin hypoperfusion and ulceration in which soft tissue debulking with liposuction improved patients’ symptoms. CASE PRESENTATION: A 39-year-old...

Introduction: In advanced lymphedema, lymphovenous anastomosis (LVA) can be a solution based on utilizing the pressure gradient between the high pressure lymphatics and low pressure veins. If the vein pressure in high, the effect affect surgery will be less optimal. This study evaluated the effect of axillary vein perivascular scar release on LVA....

Escin, a naturally derived material isolated from horse chestnut, is used as an anti-inflammatory and anti-edema agent. This study aimed to evaluate its effects on lymphedema in a rat tail model. We divided the rats into five groups. The treatment groups received topical application of escin gel at concentrations of 20%, 10%, 2%, and 0.5% for 4 wee...

Background Flaps based on the medial plantar artery (MPA) accomplish favorable surgical outcomes in palmar resurfacing due to its outstanding texture, pliability and contour, but primary closure could not be achieved at the donor site when the flap was designed to be relatively large. In this study, the kiss technique was employed for the reconstru...

Background: Diabetic foot wounds are usually chronic and prone to infection. As chronic wounds can induce various malignancies, and malignancies can sometimes present as chronic wounds, the accurate diagnosis of concomitant skin malignancies requires careful attention. We report eight cases of skin malignancies presented with diabetic foot wounds.M...

Flap reconstruction for wounds are frequently considered in cases lacking healing progress despite good wound care or complex wounds which timely coverage will benefit the overall healing process. A flap is taking a section of skin with an intact blood supply and placing it over the wound. It can be taken near the defect (local flap) or remotely (f...

Microvascular anastomoses can be challenging to perform when edematous fluids and blood continuously flood and compromise the field of view. Intermittent irrigation and suctioning disturb workflow, require an assistant, and can increase risk of arterial thrombosis from vessels being drawn into suction drains. The authors developed and patented a no...

Высокоинтенсивный фокусированный ультразвук (HIFU) оказывает омолаживающее действие на кожу с признаками фотостарения. В клинической практике процедуру применяют как один из методов стимуляции синтеза коллагена, уменьшения дряблости кожи, улучшения ее текстуры и устранения мелких морщин. Подробно описано исследование на животных, показавшее фотоста...

Background: Although many efforts have been made to create thinner anterolateral thigh (ALT) flaps, their thickness varies among patients and may be still too thick to match the shallow defects. We successfully harvested an ALT flap through the most superficial elevation plane, the superficial fat layer, which was useful to match the shallow defec...

Microsurgery, which deservedly sits on top of the reconstruction ladder, has been a boon to plastic surgery. It is because of this marvelous tool that plastic surgeons the world over have been able to tackle many reconstructive dilemmas, which were once considered to be an improbability. Microsurgery-aided revolutions have rendered a new meaning to...

Background: Adipocyte dysregulation of lipid droplet (LD) metabolism caused by altered expression of LD proteins contributes to obesity-related metabolic diseases. Objectives: We aimed to investigate whether expression levels of PLIN1, CIDEA, and CIDEC were altered in adipose tissues of women with obesity and type 2 diabetes and whether their al...

Introduction: The recovery of sensation for non-innervated perforator flap is not well understood. This prospective study aims to evaluate the quality, tendency and related factors for recovery of sensation. Material and methods: Total of 187 patients over a 6-year period were evaluated at 3, 6, 12, +24 months intervals for demographic data and...

Background: Free flap after lower extremity revascularization may enable limb salvage in defects following critical limb ischemia. This study examined the outcomes of reconstruction of ischemic diabetic foot according to the severity of the vessel occlusion and assessed whether recanalized vessels may serve as a reliable recipient vessel. Methods...

Soft tissue reconstruction of the upper extremity especially at the joint area requires a thin and pliable flap for coverage to maximize the cosmetic outcome and facilitate early mobilization preventing joint stiffness. This case presents a patient with a myxofibrosarcoma at proximal forearm. After wide excision of the tumor, the defect extended fr...

Worldwide, approximately 15% of patients with diabetes mellitus will develop foot ulcers during their lifetime. Limb salvage procedures can increase the 5-year survival rate and also improve the quality of life. Multidisciplinary team approach is very important to manage the wound in every medical aspect. Hyperglycemia, nutritional status, infectio...

Tongue reconstruction after carcinoma resection is essential to assure adequate deglutition, speech, and social interactions. Depending on the location of the carcinoma and the size of the defect, reconstructive options should be prioritized between providing mobility or bulkiness. Hemiglossectomy defects include resections of up to two-thirds of t...

Introduction Elevation in different layers achieving thin flaps are becoming relatively common practice for perforator flaps. Although postreconstruction debulking achieves pleasing aesthetic results and is widely practiced, customized approach during elevation to achieve the ideal thickness will increase efficiency while achieving the best possibl...

Acellular dermal matrix (ADM) grafts can provide coverage for full‐thickness skin defects and substitute for dermal defects. We tested the effectiveness of micronized ADM (mADM) as a dressing material, combined with negative pressure wound therapy (NPWT), for managing superficial wounds. We compared the wound healing effect of mADM in combination w...

Treatment of facial palsy is essential because neglecting this disorder can lead to serious sequelae and further damage. For an objective evaluation and consistent rehabilitation training program of facial palsy patients, a clinician’s evaluation must be simultaneously performed alongside quantitative evaluation. Recent research has evaluated facia...

Introduction: The purpose of this retrospective study is to describe, evaluate and compare the outcome between end-to-end (ETE) and side-to-end (STE) LVA for all stages of lymphedema. Material and method: Total of 123 patients were divided into ETE (n=63) or STE (n=60) group. The demographics, intraoperative and postoperative findings were evalu...

Background: Despite remarkable improvements in free flap procedures, partial flap losses in perforator flap still occur. This study aimed to analyze partial necrosis cases which underwent reconstruction of the lower extremities using anterolateral thigh (ALT) free flaps and identifies risk factors causing the occurrence of partial necrosis. Metho...

Background In lymphedema, lymphatic fluid accumulates in the interstitial space, and localized swelling appears. Lymphovenous anastomosis (LVA) is the most widely used surgery to rebuild a damaged lymphatic system; however, assessing outcome of LVA involves performing volume measurements, which provides limited information on body composition chang...

Chylothorax is a rare disease and massive lymph fluid loss can cause life-threatening condition such as severe malnutrition, weight loss, and impaired immune system. If untreated, mortality rate of chylothorax can be up to 50%. This is a case report of a 3-year-old child with iatrogenic chylothorax. Despite conservative treatment and procedures, li...

Background: This study aimed to evaluate the usefulness of the selective use of the superficial circumflex iliac artery perforator (SCIP) and the superficial inferior epigastric artery (SIEA) flap as a workhorse flap from the groin area with precise preoperative surgical planning. Methods: A total of 79 free flap reconstructions were performed i...

Objective: Leukocyte cell-derived chemotaxin 2 (LECT2) is an obesity-upregulated hepatokine inducing skeletal muscle insulin resistance. The study's aim was to explore whether LECT2 is expressed in human adipose tissue and whether the expression is dysregulated during obesity and associated with obesity-related metabolic disorders. Methods: This...

Background High-Intensity Focused Ultrasound (HIFU) therapy has emerged as an option for skin rejuvenation. However the application against photo-damaged skin remains obscure. This study evaluates the effect of HIFU against photoaged skin using a mouse model. Methods Total of 60 mice were used and divided into 3 groups; Group 1: natural aging cont...

Background: This retrospective case series compares the outcomes and postoperative oxygen levels in patients who underwent free flap versus primary closure/local flap reconstruction for ischemic diabetic foot wounds to determine the influence of free flap on the surrounding ischemic tissues. The authors hypothesized that the free flap would benefi...

Introduction Despite the extensive use of various imaging modalities, there is limited literature on comparing the reliability between indocyanine green (ICG) lymphography, MR Lymphangiogram (MRL), and high frequency color Doppler ultrasound (HFCDU) to identify lymphatic vessels. Method In this study of 124 patients, the correlation between preoper...

The treatment of diabetic foot ulceration is complex with multiple considerations involving the multidisciplinary team. Despite the efforts of the team, the aggravation of the wound often leads to limb amputation. Throughout this book, important concepts such as multidisciplinary approach, understanding the overall systemic condition, improving vas...

Introduction Among the many factors involved in reconstructive microsurgery, identifying a good recipient vessel is one of the key elements leading to a successful result. Material and Method Multiple modalities have been used to identify recipient vessels from simple palpation of axial arteries to hand-held Doppler, duplex ultrasound, computed tom...

Background: Perforator flaps have revolutionized lower limb reconstruction by offering single-stage thin, pliable coverage with an excellent aesthetic match. Although anastomosis of the flap to a major artery remains the gold standard, perforator-to-perforator anastomosis has several advantages, including expedient recipient dissection and increas...

Flaps are an essential part of reconstruction. Where the defect bed is not able to accommodate grafts or to improve function and esthetics, the flaps are used. Flap is a tissue with its own vascular supply allowing transfer from near or far one place to another. Understanding the classification (6Cs) based on circulation, constituents (composition)...

Background Patients with soft tissue tumors of extremities are at risk to develop secondary lymphedema after tumor resection caused by disruption of lymphatic vessels and sclerosis. Subsequently, this study aimed to evaluate the beneficial effects of lymphaticovenous anastomoses (LVAs) after soft tissue tumor resection of the thigh in a prophylacti...

Background: One of the critical factors for free flap survival is to maintain adequate perfusion. The authors evaluated the effect of epidural anesthesia on arterial maximal flow velocity of the free flap in microvascular lower extremity reconstruction. Methods: This is a prospective randomized study where patients were allocated to receive eith...

Background The local flaps, especially perforator and keystone flaps, are used as first-line treatment option in reconstruction of small tomoderate-sized defect of the extremity. However, the high complication rate associated with these flaps may hinder this usage. Methods This article reviews the technical and clinical aspect of using color duplex...

Context The up-regulation of TRIB3, a stress-inducible gene encoding a pseudokinase, has been implicated in the development of insulin resistance in the skeletal muscle and liver of patients with obesity and type 2 diabetes. However, there is little information regarding TRIB3 expression in human adipose tissue. Objectives To investigate whether T...

Background: A superficial circumflex iliac artery perforator flap has several advantages, such as reduced thickness, minimal donor-site morbidity, and inconspicuous scar. However, the application of a superficial circumflex iliac artery perforator flap is restricted because of its limited pedicle length. The aim of this article was to outline the...

Adequate arterial inflow is mandatory for a successful free tissue transfer. Maximizing this inflow appears to be especially important during distal lower extremity reconstruction, where perfusion pressures can be significantly lower than in the trunk or head and neck. In the current study, the authors used color and pulsed-wave Doppler ultrasonogr...

In order to provide a physiological solution for patients with breast cancer-related lymphedema (BCRL), the surgeon must understand where and how the pathology of lymphedema occurred. Based on each patient’s pathology, the treatment plan should be carefully decided and individualized. At the authors’ institution, the treatment plan is made individu...

Background Transmetatarsal amputation (TMA) preserves functional gait while avoiding the need for prosthesis. However, when primary closure is not possible after amputation, higher level amputation is recommended. We hypothesize that reconstruction of the amputation stump using free tissue transfer when closure is not possible can achieve similar b...

Lymphedema is a chronic and progressive disease that affects many of the patients who underwent cancer ablative surgery and decreases the quality of life of them. Surgical management including lymphovenous shunting and vascularized lymph node transfer become popular in the field of microsurgery. For the better outcome of microsurgical approach to l...

The microsurgical options for lower limb lymphedema is challenging. In search to improve the overall result, we hypothesized it would be beneficial to add functioning lymph node to vein anastomosis (LNVA) in addition to lymphovenous anastomosis (LVA). This is a retrospective study of 160 unilateral stage II & III lower extremity lymphedema comparin...

Supermicrosurgery is defined as microsurgery working on vessels less than 0.8 mm, allowing applications in smaller-dimension microsurgery, such as lymphedema, minimal invasive reconstruction, small parts replantation, and application of perforator as recipient. To accommodate this technique, developments and use of finer instruments, smaller suture...

The superficial circumflex iliac artery perforator flap is evolved from the groin flap, which was one of the early free flaps with a good concealed donor site. By further understanding the anatomy of perforators and elevating the flap based on it, this will provide added advantage of being a thin flap, harvesting as a composite flap, and help estim...