Nipple viability after nipple-sparing mastectomy in patients with prior circum-areolar incisions.

Nipple-areola-sparing mastectomy (NSM) is becoming more commonplace as it offers a more esthetic breast appearance while still appropriately treating malignancy. However, patients with prior circum-areolar incisions are often considered at risk for nipple viability. The authors present a case series of all patients undergoing NSM at their institution between 2012 and 2016. Eighteen consecutive female nonsmoking patients underwent 32 NSMs. None of the patients had reconstructive failures including those relating to the nipple-areola complex (NAC), such as nipple necrosis. NSM is therefore feasible in cases with prior circum-areolar incisions. These patients can be safely reconstructed with both prosthetic devices and autologous tissue.

Comment to: "Complications and Outcomes After Gynecomastia Surgery: Analysis of 204 Pediatric and 1583 Adult Cases from a National Multi-center Database".

Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Enhanced Recovery After Surgery: The Plastic Surgery Paradigm Shift.

BACKGROUND: With a focus on providing high quality care and reducing facility based expenses there has been an evolution in perioperative care by way of enhanced recovery after surgery (ERAS). ERAS allows for a multidisciplinary and multimodal approach to perioperative care which not only expedites recovery but maximizes patient outcomes. This paradigm shift has been generally accepted by most surgical specialties, including plastic surgery. OBJECTIVES: The goal of this study was to evaluate the impact of ERAS on outcomes in cosmetic plastic surgery. METHODS: A prospective study consisting of phone call questionnaires was designed where patients from two senior plastic surgeons (N.H.R. and J.D.F.) were followed. The treatment group (n = 10) followed an ERAS protocol while the control group (n = 12) followed the traditional recovery after surgery which included narcotic usage. Patients were contacted on postoperative days (POD) 0 through 7+ and surveyed about a number of outcomes measures. RESULTS: The ERAS group demonstrated a significant reduction in postoperative pain on POD 0, 1, 2, and 3 (all P < 0.01). There was also statistically less nausea/vomiting, fatigue/drowsiness, constipation, and hindrance on ambulation compared to the control group (all P < 0.05). Significance was achieved for reduction in fatigue/drowsiness on POD 0 and 1 (P < 0.01), as well as ability to ambulate on POD 0 and 3 (P = 0.044). Lastly, opioid use (P < 0.001) and constipation (P = 0.003) were decreased. CONCLUSIONS: ERAS protocols have demonstrated their importance within multiple surgical fields, including cosmetic plastic surgery. The utility lies in the ability to expedite patient's recovery while still providing quality care. This study showed a reduction in postoperative complaints by avoiding narcotics without an increase in complications. Our findings signify the importance of ERAS protocols within cosmetic plastic surgery.

Complications and Outcomes After Gynecomastia Surgery: Analysis of 204 Pediatric and 1583 Adult Cases from a National Multi-center Database.

BACKGROUND: Gynecomastia is a common disease that is prevalent across all age groups of boys and men. Although benign in nature, it can lead to psychological and social distress, prompting affected patients to seek medical attention. Management strategies include observation and drug therapy, yet surgical procedures remain the hallmark of treatment. The goal of this study was to analyze patient demographics, outcomes, and complication rates of gynecomastia surgery in a large multi-institutional cohort. METHODS: We performed a retrospective analysis of the American College of Surgeons National Surgical Quality Improvement Program adult and pediatric databases to produce two cohorts that underwent gynecomastia surgical repair. The two populations were compared for comorbidities, perioperative details, and complication rates. Multivariate analyses helped detect risk factors associated with adverse events. RESULTS: A total of 204 pediatric and 1583 adult male patients were identified in our analysis. Mean ages were 15.8 and 39.6 years, respectively. A BMI of 28.2 in the latter cohort revealed an overweight adult population. Preoperative comorbidities (0.0-4.9% in children, 0.0-6.4% in adults) and American Society of Anesthesiologists scores (ASA 1 + 2: 98.5 and 82.7%) symbolized a healthy population. Procedures were subsequently performed mostly as outpatient (84.3 and 93.9%) and with short hospitalization durations (0.27 and 0.06 days). Our results demonstrated low surgical (3.9 and 1.9%) and medical (0.0 and 0.3%) complications within the standardized 30-day postoperative period. Children and adolescents, however, required double mean operative times compared to adults (111.3 vs 56.7 min). CONCLUSION: Operative gynecomastia treatment remains a safe treatment modality across all age groups. Patients with known preoperative medical or surgical comorbidities necessitate more extensive perioperative assessment and monitoring. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Impact of Metabolic Syndrome on the Morbidity and Mortality of Patients Undergoing Panniculectomy.

BACKGROUND: Metabolic syndrome (MetS) is defined as the concomitant disease process of obesity and at least two of the following variables: diabetes, hypertension, hypertriglyceridemia, or reduced high-density lipoprotein. These entities are well established as risk factors for complications following surgery. Obese patients are particularly prone to the development of MetS. The authors therefore aimed at elucidating the impact of MetS on the perioperative panniculectomy outcomes. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was analyzed for all primary procedures of panniculectomy from 2010 through 2015. The cases were stratified based on the presence or absence of MetS and evaluated for demographic data, intraoperative details, and their morbidity and mortality within 30 days after surgery. RESULTS: A total of 7030 cases were included in this study. Patients with MetS (6.2%) were of significantly worse health, required more emergency admissions (p = 0.022), longer hospitalization (p < 0.001), and more frequently inpatient procedures (p < 0.001) compared to the control group without MetS (3.8%). Plastic surgery was the predominant specialty operating on 79.5% of all cases. Surgical (23.3 vs. 8.7%) complications, readmission (8.7 vs. 3.0%), and reoperations (6.9 vs. 3.1%) rates were all significantly higher in patients with MetS that those without (p < 0.001). One fatality occurred in each cohort (0.23 vs. 0.02%, p = 0.010). CONCLUSION: Comorbidities are not uncommon in patients undergoing panniculectomy, especially in those diagnosed with MetS. Health-care providers need to be aware of the increased morbidity and mortality in this high-risk subgroup and need to consider preoperative optimization and management before proceeding with surgery. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Staged breast reconstruction utilizing primary nipple repositioning surgery prior to nipple-sparing mastectomy.

Staged nipple-sparing mastectomy (NSM) following mastopexy or breast reduction has become increasingly utilized in patients with large or ptotic breasts. The safety and efficacy of this approach has been demonstrated in recent years. However, the optimal timing between stages has not been established. The authors provide their experience with this staged approach with emphasis on timing between stages. An institutional review board approved this retrospective study. Data of all patients at a single institution who underwent staged NSM following mastopexy or reduction mammaplasty for therapeutic or prophylactic oncologic surgical management from 2016 to 2020 were reviewed. Timing between stages as well as surgical, oncologic, aesthetic, and patient-reported outcomes were evaluated. Nineteen patients (38 breasts) underwent staged NSM following planned mastopexy/breast reduction. The mean time interval between stages was 25 weeks. No patients developed nipple areolar complex necrosis. Infection and hematoma were seen in one breast (2.6%) and seroma in two (5.3%) after NSM. Delayed wound healing was seen in eight breasts (21.1%) after first stage mastopexy/reduction and in 12 breasts (31.6%) after NSM. Skin flap necrosis was noted in two breasts (5.3%) after NSM. No patients developed oncological recurrence. Mean patient-reported post-operative satisfaction and well-being scores were 63 and 67 out of 100, respectively. The authors describe their experience with staged NSM following nipple repositioning procedures. Their results suggest that this procedure can be performed safely with cosmetically favorable results if surgeons wait an average of 25 weeks between first and second stage procedures.

The Business of Employed Plastic Surgery: Creating Your Seat at the Table.

BACKGROUND: While the landscape of medicine changes, hospital employment continues to gain popularity in surgical specialties. The number of plastic surgeons entering an employed relationship has also grown, offering new opportunities and challenges alike. The authors studied the profitability of plastic surgery to the hospital and the necessity of the specialty to hospital administration through financial net revenue, contribution margin, and payer mix, to help plastic surgeons realize and capitalize on their importance and contribution to the hospital system. METHODS: Facility net revenue and contribution margin from Houston Methodist West Hospital were evaluated. Average net revenue and contribution margin for inpatient and outpatient cases for plastic surgery, orthopedic surgery, and all combined surgical specialties were studied for the 2018 and 2019 fiscal years. RESULTS: The authors demonstrated net increase per year for both outpatient and inpatient revenue in favor of plastic surgery versus orthopedics and combined surgical specialties. Plastic surgery contributed higher facility net revenue when compared to orthopedics, contributing 20 percent more per outpatient case and 86 percent more per inpatient case. A higher contribution margin for each year was realized for inpatient cases versus orthopedics and combined surgical specialties, increasing by 8 percent and 53 percent and 61 percent and 86 percent, respectively. CONCLUSIONS: A surgeon's ability to present objective financial data and develop leadership roles within the hospital system can lead to a favorable outcome for both physician and hospital. An objective dialogue with hospital administration is critical and offers an avenue to negotiate the development of your practice.

Revision Facelift and Neck Lift.

Facial rejuvenation procedures have become more commonly performed due to an increasing elderly population and greater general public acceptance. As a result, patients are now increasingly undergoing secondary and tertiary rhytidectomies to treat natural aging and/or to correct complications from prior procedures. Revision face and neck lifts are more complex by nature of the procedure and require a comprehensive preoperative assessment for enhanced outcomes. In this review, we discuss the preoperative evaluation, surgical challenges encountered, primary face and neck lift deformities, and their surgical management for patients undergoing secondary face and neck lifts.

Safety and efficacy of suction-assisted lipectomy on irradiated skin and subcutaneous tissue.

Reconstruction of soft tissue defects with standard myocutaneous or fasciocutaneous flaps often results in contour deformities due either to intrinsic characteristics of the flap or due to initial overcorrection of the defect when postoperative radiation therapy is planned. In such cases, revision with suction-assisted lipectomy is often necessary to achieve optimal cosmetic results. Since liposuction has been associated with decreased tissue perfusion, there remains significant concern that revision of irradiated flaps with liposuction places the patient at high risk for tissue necrosis and wound healing difficulty. To determine the safety of liposuction on irradiated tissue, the authors reviewed our experience of 9 patients treated for cancer with extirpation of tumor and immediate reconstruction with a free or pedicle flap. All patients required radiation therapy and ultimately underwent revision with liposuction due to contour irregularity. Flaps were treated with 60 to 64 Gy and between 30 and 300 mL of fat was removed at 6 weeks to 9 months after final dose of radiation therapy. All patients achieved improvement in contour with no significant fat or skin necrosis. We conclude that suction-assisted lipectomy of irradiated tissue is safe and effective for flap revision following conventional doses of radiation therapy.

Subcutaneous temporal browlift under local anesthesia: a useful technique for periorbital rejuvenation.

BACKGROUND: Various techniques have been described for periorbital rejuvenation and correction of the ptotic brow, including the coronal brow lift, the endoscopic brow lift, anterior hairline foreheadplasty in the subgaleal, subperiosteal, or subcutaneous planes, and the subcutaneous temporal brow lift. OBJECTIVES: The authors present results from a series of 28 patients treated with subcutaneous temporal brow lift over nearly four years. METHODS: A retrospective chart review was conducted of 28 patients who were treated with subcutaneous temporal brow lift by the senior author (JDF) between July 2003 and January 2007. All patients underwent the same subcutaneous temporal brow lift procedure under local anesthesia in an office-based setting. No combined procedures were performed on any of the patients in this series. RESULTS: Of the 28 patients, 27 were female and one was male; mean age was 54 years. Five patients underwent a unilateral brow lift for asymmetry and 23 patients underwent a bilateral procedure. The mean length of follow-up was 10.8 months. Scarring was minimal and rated as "good" or "excellent" by both patients and surgeon. The effectiveness of the browlift was also rated as "good" or "excellent" by all but one patient. Two patients underwent revision-one for scar revision and the other for a greater degree of lift. There were no incidences of hematoma, infection, numbness, or excessive scarring. CONCLUSIONS: The subcutaneous temporal brow lift is an effective, reproducible, and inexpensive technique that can be performed safely under local anesthesia.

Reconstruction of full-thickness calvarial defect: a role for artificial dermis.

The reconstruction of scalp defects presents a clinical challenge. Free tissue transfer has played an increasingly important role in the reconstruction of complex scalp defects. In many cases, patient medical comorbidities along with the length of the operative procedures incurs significant patient risk. Artificial dermis, used extensively in burn reconstruction, has emerged as a reconstructive option for the coverage of many complex posttraumatic and postoncologic defects; however, none have described its use for the reconstruction of full-thickness calvarial defects with exposed dura.We report a clinical case of an elderly, medically compromised patient with a full-thickness scalp defect, who underwent successful reconstruction with artificial dermis.The use of artificial dermis and subsequent skin grafting, as was performed in this case, provides a less invasive, less intensive, and satisfactory means of soft tissue reconstruction for full-thickness calvarial defects.

Umbilical hernia repair in conjunction with abdominoplasty: a surgical technique to maintain umbilical blood supply.

Abdominal wall hernias are often diagnosed on clinical examination or encountered intraoperatively during an abdominoplasty. Traditional surgical techniques for abdominoplasty and umbilical hernia repair, when performed simultaneously, can potentially compromise the vascular supply to the umbilicus. The authors describe a simplified surgical technique for the correction of umbilical hernias in conjunction with abdominoplasty. This procedure avoids any fascial incisions immediately adjacent to the umbilicus, thereby maintaining a maximal blood supply to the umbilical stalk. Over a six-year period, 17 patients underwent the described procedure. None have had a recurrence of their hernia or umbilical necrosis, and the aesthetics of the umbilicus have been improved.

Training Effects of Visual Stroboscopic Impairment on Surgical Performance: A Randomized-Controlled Trial.

OBJECTIVE: There have been numerous advances to accelerate and improve quality and dexterous proficiency of surgical training to meet the growing US demand of graduating surgeons. The authors aimed to investigate the learning effects of such limited visual input on the surgical proficiency in untrained novice surgeons. DESIGN: A prospective randomized-controlled study was created with 11 participants in the study and 11 in the control group. SETTING: An inanimate surgical simulation lab of a tertiary academic institution (Houston Methodist Hospital, Houston, Texas). PARTICIPANTS: Adult medical students in the experimental group were wearing stroboscopic eyewear while performing the same tasks as students in the control group with normal vision. For 5 weeks, the subjects were scored during 3 standardized surgical tasks from the American College of Surgeons and the Association of Program Directors in Surgery Resident Skills Curriculum: knot tying, simple interrupted sutures, and a running stitch. Pretrial, we employed the State-Trait Anxiety Inventory and post-trial, the NASA Task Load Index. RESULTS: The demographic characteristics of our study participants were uniformly distributed between the 2 cohorts: each group had 7 males and 4 females. Average ages were 23.6 and 24.2 years (p = 0.471). The anxiety was low during all 5 sessions and indifferent between both groups. At the end of the study, no changes were observed in the stroboscopic group for the knot-tying task (p = 0.619). However, for the simple interrupted and the running stitch, the students with stroboscopic glasses performed significantly better (p = 0.001 and p = 0.024, respectively). The stroboscopic students also had significantly lower NASA workload scores (p = 0.001). CONCLUSIONS: Regular training with stroboscopic glasses that limit visual input has a significant positive effect on the technical skills of novice surgical trainees with regards to more complex tasks such as multiple simple interrupted suturing or running suture. Intermittently impaired vision is beneficial in the early education of students and surgical residents.

Preventing recurrent pressure ulcers in veterans with spinal cord injury: impact of a structured education and follow-up intervention.

OBJECTIVE: To test the hypothesis that enhanced education and structured follow-up after pressure ulcer surgery will result in fewer recurrences. DESIGN: Randomized controlled trial. SETTING: Veterans Affairs medical center. PARTICIPANTS: Forty-nine veteran men with spinal cord injury or dysfunction were approached on admission for pressure ulcer surgery. Five never had surgery, 2 refused to participate, and one withdrew. Forty-one were randomized into 3 groups. Three participants' ulcers did not heal, so follow-up could not begin. INTERVENTIONS: Group 1 received individualized pressure ulcer education and monthly structured telephone follow-up (n=20); group 2 received monthly mail or telephone follow-up without educational content (n=11); and group 3 received quarterly mail or telephone follow-up without educational content (n=10). Follow-up continued until recurrence, death, or 24 months. MAIN OUTCOME MEASURE: Time to pressure ulcer recurrence. RESULTS: Group 1 had a longer average time to ulcer recurrence or end of study than groups 2 and 3 (19.6 mo, 10.1 mo, 10.3 mo; P=.002) and had a smaller rate of recurrence (33%, 60%, 90%; P=.007). Survival analysis confirmed these findings (P=.009). CONCLUSIONS: Individualized education and structured monthly contacts may be effective in reducing the frequency of or delaying pressure ulcer recurrence after surgical repair of an ulcer.

Multi-institutional analysis of independent predictors for burn mortality in the United States.

BACKGROUND: Previous reports individually identified different factors that predict death after burns. The authors employed the multi-center American Burn Association's (ABA) National Burn Repository (NBR) to elucidate which parameters have the highest negative impact on burn mortality. METHODS: We audited data from the NBR v8.0 for the years 2002-2011 and included 137,061 patients in our study. The cases were stratified into two cohorts based on the primary outcome of death/survival and then evaluated for demographic data, intraoperative details, and their morbidity after admission. A multivariable regression analysis aimed to identify independent risk factors associated with mortality. RESULTS: A total of 3.3% of patients in this analysis did not survive their burn injuries. Of those, 52.0% expired within 7 days after admission. Patients in the mortality cohort were of older age (p < 0.001), more frequently female (p < 0.001), and had more pre-existing comorbidities (p < 0.001). Total body surface area (TBSA), inhalation injury, hospitalization time, and occurrence of complications were higher compared to survivors (p < 0.001). Lack of insurance (odds ratio (OR) = 1.84, confidence interval (CI) 1.38-2.46), diabetes (OR = 1.24, CI 1.01-1.53), any complication (OR = 4.09, CI 3.27-5.12), inhalation injury (OR = 3.84, CI 3.38-4.36), and the need for operative procedures (OR = 2.60, CI 2.20-3.08) were the strongest independent contributors to mortality after burns (p < 0.001). Age (OR = 1.07, CI 1.06-1.07) and TBSA (OR = 1.09, CI 1.09-1.09) were significant on a continuous scale (p < 0.001) while overall comorbidities were not a statistical risk factor. CONCLUSION: Uninsured status, inhalation injury, in-hospital complications, and operative procedures were the strongest mortality predictors after burns. Since most fatal outcomes (52.0%) occur within 7 days after injury, physicians and medical staff need to be aware of these risk factors upon patient admission to a burn center.

Multi-institutional Analysis of Surgical Management and Outcomes of Mandibular Fracture Repair in Adults.

Mandibular fractures are rare, most commonly occurring in young male patients who present with facial trauma. The etiology, incidence, and presentation vary among previous publications depending on cultural and socioeconomic factors of the region of origin. This multi-institutional study aims to present demographic characteristics, surgical treatment, and clinical outcomes of surgical repair of mandible fractures in the United States. An analysis of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) adult databases of the years 2006 through 2014 was performed identifying 940 patients with an International Classification of Diseases, version 9 (ICD-9) diagnosis of either closed or open fracture of the mandible. Preoperative, perioperative, and postoperative details were categorized and evaluated for these two cohorts. Multivariate analysis was performed to detect risk factors related to any complications. Patients were predominantly male (85.7%), young with a mean age of 34.0 ± 14.8 years, and relatively healthy with body mass index of 23.6 ± 8.2 and an American Society of Anesthesiologists (ASA) class of 1 or 2 (84.4%). However, more than half were regular smokers (51.1%). The top five most frequent procedures performed for mandibular repair were exclusively open surgical approaches with internal, external, or interdental fixation in both cohorts. Patients with open fractures were more often admitted as emergencies, treated inpatient, required longer operative times, and presented with more contaminated wounds ( p < 0.05). Overall, medical (1.7%) and surgical complications (3.7%) were low. A high ASA class 3 or above and emergency operations were identified as risk factors for medical adverse events. Despite frequent concomitant injuries after trauma and a diverse array of mandibular injury types, our patient sample demonstrated favorable outcomes and low complication rates. Open surgical techniques were the most common procedures in this study representing the American population.

Safety of open ventral hernia repair in high-risk patients with metabolic syndrome: a multi-institutional analysis of 39,118 cases.

BACKGROUND: Metabolic syndrome (MetS) entails the simultaneous presence of a constellation of dangerous risk factors including obesity, diabetes, hypertension, and dyslipidemia. The prevalence of MetS in Western society continues to rise and implies an elevated risk for surgical complications and/or poor surgical outcomes within the affected population. OBJECTIVE: To assess the risks and outcomes of multi-morbid patients with MetS undergoing open ventral hernia repair. SETTING: Multi-institutional case-control study in the United States. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was sampled for patients undergoing initial open ventral hernia repair from 2012 through 2014 and then stratified into 2 cohorts based on the presence or absence of MetS. Statistical analyses were performed to evaluate preoperative co-morbidities, intraoperative details, and postoperative morbidity and mortality to identify risk factors for adverse outcomes. RESULTS: Mean age (61.0 versus 56.0 yr, P<.001), body mass index (39.2 versus 31.1, P<.001), and prevalence of co-morbidities of multiple organ systems were significantly higher (P<.001) in the MetS cohort compared to control. Patients with MetS received higher American Society of Anesthesiologists classifications (81.0% versus 43.1% class 3 or higher, P<.001), were more likely to require operation as emergency cases (11.4% versus 7.2%, P<.001), required longer operative times (103 versus 87 min, P<.001), had longer hospitalizations (3.5 versus 2.4 d, P<.001), and had more contaminated wounds (15.9% versus 12.0% class 2 or higher, P<.001). Overall, they had more medical (7.5% versus 4.2%, P<.001), and surgical complications (9.7% versus 5.4%, P<.001), experienced more readmissions (8.3% versus 5.7%, P<.001) and reoperations (3.4% versus 2.5%, P<.001), and were at higher risk for eventual death (.8% versus .5%, P=.008). CONCLUSIONS: The presence of MetS is related to a multitude of unfavorable outcomes and increased mortality after open ventral hernia repair compared with a non-MetS control group. MetS is a useful marker for high operative risk in a population that is generally prone to obesity and its associated diseases.

Vascularized fat transfer.

The use of free tissue transfers has dramatically improved the outcomes of soft tissue reconstructions of the face. This is particularly true when large volumes of soft tissue are needed or when the recipient bed has a compromised local blood supply. Although traditional fat grafting procedures often allow for satisfactory results in some patients, the use of scapular and parascapular free tissue transfers has markedly improved the predictability of these reconstructions, often in a single stage. As perforator flap reconstructions evolve over time, these types of flaps may eventually supplant the available fasciocutaneous free flaps as the flap of choice in these reconstructions primarily because of improved donor site scarring and morbidity.

Self-contained diffuse optical imaging system for real-time detection and localization of vascular occlusions.

Free flap surgery is a procedure where healthy tissue is transferred from a donor site to a recipient site of the body to fill a defect without maintaining the original blood supply to the flap. The anastomosis of the vascular network of the flap to the blood vessels adjacent to the recipient site has associated risks of arterial and/or venous occlusions that must be promptly detected to avoid temporary or permanent tissue damage. In this work, we present a skin-contact diffusion optical imaging (DOI) system able to continuously provide a three-dimensional representation of the flap oxygenation to promptly detect vascular occlusions potentially occurring in the flap. Multiple near-infrared LEDs and photodetectors were embedded into a self-contained optical sensor for prolonged monitoring of concentration changes of oxygenated (HbO) and deoxygenated hemoglobin (HbR) at multiple locations and depths. A time-efficient algorithm mapped measured oxygenation changes in a three-dimensional volume to allow surgeons and clinical personnel to detect and localize abnormal blood perfusion changes during or after surgery, in time for corrective intervention. The image reconstruction algorithm was validated using computerized flap models in which oxygenation was synthetically altered, whereas the optical system was preliminarily tested on a healthy forearm simulating a flap undergoing arterial and venous occlusions, proving the feasibility of implementing DOI in the form of a wearable patch for prolonged perfusion monitoring.