A Classification System for Partial and Complete DIEP Flap Necrosis Based on a Review of 17,096 DIEP Flaps in 693 Articles Including Analysis of 152 Total Flap Failures:

Contemporary Microsurgical Breast Reconstruction: Abdominally Based Flaps

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the types of abdominally based flaps, their anatomy, and their drawbacks. 2. Understand important aspects of the history and physical examination of patients wishing to undergo these procedures. 3. Understand the benefits of preoperative planning and its role in avoiding complication. 4. Understand the operative steps of the procedures and tips to increase efficiency. 5. Understand the postoperative care of these patients and the role of enhanced recovery pathways.

SUMMARY

In this article, the authors review the history, current state, and future directions related to abdominally based microsurgical breast reconstruction. This article covers preoperative, intraoperative, and postoperative considerations intended to improve patient outcomes and prevent complications. Evidence-based findings are reported when available to comprehensively review important aspects of these procedures.

Extrinsic Vascular Pathway Preservation Improves Survival in a Rat Three-Territory Flap Model Based on the Deep Circumflex Iliac Artery

BACKGROUND

Extended flaps are commonly applied for large defects. However, a postoperative flap necrosis incidence of 11% to 44% remains a major complication. Previous clinical studies have shown that maintaining the extrinsic vascular pathway (EVP) can increase the survival area of extended flaps. The authors hypothesized that preserving the EVP would improve flap survival by reducing blood resistance within the vascular territory.

METHODS

Twenty-four adult male Sprague-Dawley rats were used. Tissue samples were obtained from eight untreated rats as a baseline control. Three-territory flaps were elevated in the remaining 16 rats. The EVP was preserved or ligated. Flap perfusion was assessed immediately using indocyanine green angiography. Rats were euthanized on day 7. The flap survival area was measured using Adobe Photoshop. Hematoxylin and eosin staining, CD31 immunostaining, and Western blot analysis of vascular endothelial growth factor protein expression were used to quantitatively assess vasodilation and angiogenesis in choke zones.

RESULTS

Indocyanine green angiography revealed that blood could flow through the preserved EVP and perfuse the third vascular territory of the flap. EVP preservation significantly increased flap survival area (86.3%, 19.3% difference; P < 0.001), promoted vasodilation (5.0/choke zone, 3.0/choke zone difference; P = 0.013) and angiogenesis (29.3/mm 2 , 14.3/mm 2 difference; P = 0.002), and increased vascular endothelial growth factor expression (0.6, 0.2 difference; P = 0.067) in the second choke zone.

CONCLUSIONS

EVP preservation improves flap survival in this rat three-territory flap model. Further investigation in large-animal models is required for clinical translation.

CLINICAL RELEVANCE STATEMENT

Although further validation in large animal models and prospective clinical trials are necessary to verify the efficacy of the authors' hypothesis, their findings suggest that the EVP preservation procedure could provide an alternative for surgeons to create an extended flap in defect reconstruction.

Secondary solution for breast reconstruction following total DIEP flap loss: A single-center experience after 3270 DIEP flaps

BACKGROUND

Total deep inferior epigastric perforator (DIEP) flap failure is a significant concern in autologous breast reconstruction. Literature on secondary reconstruction options following total flap failure is limited. This study outlines the outcomes of patients who underwent reconstruction post-DIEP flap failure at our institution.

METHODS

We conducted a retrospective analysis of patients receiving autologous breast reconstruction between 2004 and 2021. We aimed to identify causes of total DIEP flap failure, outcomes of revision surgery, and outcomes of secondary breast reconstruction procedures.

RESULTS

From 2004 to 2021, 3456 free flaps for breast reconstruction were performed, with 3270 being DIEP flaps for 2756 patients. DIEP flap failure was observed in 40 cases (1.22%). Bilateral reconstructions had a higher failure rate (2.31%) than unilateral (0.72%). The primary cause was intraoperative complications during flap harvest (18 cases), followed by insufficient arterial perfusion (seven cases). Other causes included postoperative hematoma (seven cases), venous congestion (six cases), and late-onset fat necrosis (two cases). Post-failure, five patients received a second free flap with three cases of repeated flap failure. Twenty patients received implant-based reconstruction with two cases of reconstruction failure, while seven patients received a pedicled latissimus dorsi (LD) flap reconstructions with no cases of reconstruction failure. Eight patients declined further reconstruction.

CONCLUSION

A second free flap post-DIEP failure was associated with a high risk of reconstruction failure, suggesting the need for careful patient selection. Implant-based and pedicled LD flap seem to be reliable secondary reconstruction options.

Systematic review of pathologic markers in skin ischemia with and without reperfusion injury in microsurgical reconstruction: Biomarker alterations precede histological structure changes

BACKGROUND

Ischemia and ischemia-reperfusion injury contribute to partial or complete flap necrosis. Traditionally, skin histology has been used to evaluate morphological and structural changes, however histology does not detect early changes. We hypothesize that morphological and structural skin changes in response to ischemia and IRI occur late, and modification of gene and protein expression are the earliest changes in ischemia and IRI.

METHODS

A systematic review was performed in accordance with PRISMA guidelines. Studies reporting skin histology or gene/protein expression changes following ischemia with or without reperfusion injury published between 2002 and 2022 were included. The primary outcomes were descriptive and semi-quantitative histological structural changes, leukocyte infiltration, edema, vessel density; secondary outcomes were quantitative gene and protein expression intensity (PCR and western blot). Model type, experimental intervention, ischemia method and duration, reperfusion duration, biopsy location and time point were collected.

RESULTS

One hundred and one articles were included. Hematoxylin and eosin (H&E) showed inflammatory infiltration in early responses (12-24 h), with structural modifications (3-14 days) and neovascularization (5-14 days) as delayed responses. Immunohistochemistry (IHC) identified angiogenesis (CD31, CD34), apoptosis (TUNEL, caspase-3, Bax/Bcl-2), and protein localization (NF-κB). Gene (PCR) and protein expression (western blot) detected inflammation and apoptosis; endoplasmic reticulum stress/oxidative stress and hypoxia; and neovascularization. The most common markers were TNF-α, IL-6 and IL-1β (inflammation), caspase-3 (apoptosis), VEGF (neovascularization), and HIF-1α (hypoxia).

CONCLUSION

There is no consensus or standard for reporting skin injury during ischemia and IRI. H&E histology is most frequently performed but is primarily descriptive and lacks sensitivity for early skin injury. Immunohistochemistry and gene/protein expression reveal immediate and quantitative cellular responses to skin ischemia and IRI. Future research is needed towards a universally-accepted skin injury scoring system.

Standardized Pre-clinical Surgical Animal Model Protocol to Investigate the Cellular and Molecular Mechanisms of Ischemic Flap Healing

BACKGROUND

Some of the most complex surgical interventions to treat trauma and cancer include the use of locoregional pedicled and free autologous tissue transfer flaps. While the techniques used for these reconstructive surgery procedures have improved over time, flap complications and even failure remain a significant clinical challenge. Animal models are useful in studying the pathophysiology of ischemic flaps, but when repeatability is a primary focus of a study, conventional in-vivo designs, where one randomized subset of animals serves as a treatment group while a second subset serves as a control, are at a disadvantage instigated by greater subject-to-subject variability. Our goal was to provide a step-by-step methodological protocol for creating an alternative standardized, more economical, and transferable pre-clinical animal research model of excisional full-thickness wound healing following a simulated autologous tissue transfer which includes the primary ischemia, reperfusion, and secondary ischemia events with the latter mimicking flap salvage procedure.

RESULTS

Unlike in the most frequently used classical unilateral McFarlane's caudally based dorsal random pattern skin flap model, in the herein described bilateral epigastric fasciocutaneous advancement flap (BEFAF) model, one flap heals under normal and a contralateral flap-under perturbed conditions or both flaps heal under conditions that vary by one within-subjects factor. We discuss the advantages and limitations of the proposed experimental approach and, as a part of model validation, provide the examples of its use in laboratory rat (Rattus norvegicus) axial pattern flap healing studies.

CONCLUSIONS

This technically challenging but feasible reconstructive surgery model eliminates inter-subject variability, while concomitantly minimizing the number of animals needed to achieve adequate statistical power. BEFAFs may be used to investigate the spatiotemporal cellular and molecular responses to complex tissue injury, interventions simulating clinically relevant flap complications (e.g., vascular thrombosis) as well as prophylactic, therapeutic or surgical treatment (e.g., flap delay) strategies in the presence or absence of confounding risk factors (e.g., substance abuse, irradiation, diabetes) or favorable wound-healing promoting activities (e.g., exercise). Detailed visual instructions in BEFAF protocol may serve as an aid for teaching medical or academic researchers basic vascular microsurgery techniques that focus on precision, tremor management and magnification.

A systematic review of the scientific evidence of venous supercharging in autologous breast reconstruction with abdominally based flaps

BACKGROUND

Abdominally based free flaps are commonly used in breast reconstruction. A frequent complication is venous congestion, which might contribute to around 40% of flap failures. One way to deal with it is venous supercharging. The primary aim of this study was to investigate the scientific evidence for the effects of venous supercharging.

METHODS

A systematic literature search was conducted in PubMed, CINAHL, Embase, and Cochrane library. The included articles were critically appraised, and certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

RESULTS

Thirty-six studies were included. Most studies had serious study limitations and problems with directness. Three studies report 'routine' use of venous supercharging and performed it prophylactically in patients who did not have clinical signs of venous congestion. Seventeen studies report on flap complications, of which one is a randomised controlled trial demonstrating statistically significant lower complication rates in the intervention group. The overall certainty of evidence for the effect of a venous supercharging on flap complications, length of hospital stay and operative time, in patients without clinical signs of venous congestion, is very low (GRADE ⊕ ⊕ ⊝ ⊝), and low on and surgical takebacks (GRADE ⊕ ⊕ ⊝ ⊝). Twenty-one studies presented data on strategies and overall certainty of evidence for using radiological findings, preoperative measurements, and clinical risk factors to make decisions on venous supercharging is very low (GRADE ⊕ ⊝ ⊝ ⊝).

CONCLUSION

There is little scientific evidence for how to predict in which cases, without clinical signs of venous congestion, venous supercharging should be performed. The complication rate might be lower in patients in which a prophylactic venous anastomosis has been performed.

TRIAL REGISTRATION

PROSPERO (CRD42022353591).

Cadaveric Study for Safe Elevation of a Profunda Artery Perforator Flap: Anatomy of the Perforators and Obturator Nerves

BACKGROUND

 This cadaveric study aimed to describe the anatomy of the profunda artery perforators (PAPs).

METHODS

 In total, nine free cadavers with 18 upper thighs were dissected, 12 of which were from female cadavers, and 6 were from male cadavers. The average age of the cadavers was 84.7 ± 4.2 years. Dissection was performed to evaluate the anatomic position and characteristics of the femoral PAPs. The perforator distance from the gluteal sulcus, number of perforators, perforating muscles, diameter of the perforators, origin of the perforators, and number of nerves passing above and below the perforators were determined.

RESULTS

 The average number of perforators that penetrate the adductor magnus muscle was 2.5. The average distance from the origin of the perforators to the gluteal sulcus was 71.72 ± 28.23 mm. The average numbers of the obturator nerves passing above and below the perforator in the adductor magnus muscle were 1.3 (range, 0-4) and 0.7 (range, 0-2), respectively.

CONCLUSION

 The results provide a detailed anatomic basis for the PAP flap. The perforators of a PAP flap may be included in a flap with a transverse design. Sacrificing the small obturator nerves during dissection may not lead to significant donor site morbidity.

Natural course of fat necrosis after deep inferior epigastric perforator flap-based breast reconstruction: Evaluation based on ultrasound examination

BACKGROUND

Fat necrosis, often developing following deep inferior epigastric perforator (DIEP) flap-based breast reconstruction, is not a negligible complication. This study aimed to conduct a longitudinal assessment of the clinical course of fat necrosis in breast reconstruction with DIEP flap.

METHODS

Among patients undergoing immediate DIEP flap-based breast reconstruction between 2009 and 2017, those who developed fat necrosis on ultrasonographic examination and did not undergo surgical intervention for the lesion were reviewed. Changes in lesion size over time were assessed based on regular ultrasound examinations.

RESULTS

A total of 37 cases were analyzed, with a mean follow-up of 52.6 months (range, 19-114). Their mean age was 45.8 years, and the mean body mass index was 23.4 kg/m2 . Of these, 21 lesions had disappeared over time. The mean time from detection to the disappearance was 30.4 months. The remaining 16 lesions did not disappear and persisted for a median follow-up of 43.5 months. Compared with the lesions that persisted, those that disappeared were significantly smaller in initial size (p = 0.040) and had a lower inset ratio of the harvested flap (p = 0.006). The optimal cutoff value for the initial size for disappearance was ≤1.97 cm. Among the lesions >1.97 cm in size, 6 (35.3%) of 17 lesions disappeared, whereas in those ≤1.97 cm, 15 (75.0%) of 20 disappeared over time, with a significant difference (p = 0.041).

CONCLUSION

The natural course of fat necrosis that develops following the DIEP flap may differ according to its initial size.

Efficacy of superficial inferior epigastric vein superdrainage in free TRAM and DIEP flap: An indocyanine green angiography study of 68 cases

BACKGROUND

This study aimed to evaluate the clinical efficacy of venous augmentation using superficial inferior epigastric vein (SIEV) in free transverse rectus abdominis musculocutaneous (TRAM) and deep inferior epigastric artery perforator (DIEP) flap and investigate the factors that hinder the venous superdrainage.

METHODS

A retrospective review of 62 free muscle-sparing (MS)-TRAM and 6 DIEP unilateral breast reconstructions from September 2017 to July 2022. Intraoperative indocyanine green angiography was performed on the harvested flap, with the SIEV contralateral to the pedicle side clamped and unclamped for 20 min. The relative ratio of hypoperfused area to the total flap area was calculated and compared quantitatively. The preoperative computed tomography (CT) angiography was reviewed to obtain information on the SIEV diameter and number of midline-crossing medial branches.

RESULTS

The participants were categorized into three groups: 42 patients in Group 1 (>3% decrease in hypoperfused area), 20 patients in Group 2 (change in hypoperfused area ranging from -3% to 3%), and six patients in Group 3 (>3% increase in hypoperfused area). The mean number of midline-crossing branches (p = 0.002) and mean difference in the diameter of bilateral SIEVs (p = 0.039) were significantly greater in Group 1 than in the other groups.

CONCLUSIONS

Thirty-eight percent (26/68 cases) resulted in sustained or aggravated perfusion after SIEV superdrainage. Superdrainage using the contralateral SIEV in free MS-TRAM/DIEP flap is recommended when there are more than two midline-crossing medial branches of SIEV and when the caliber of SIEV is relatively greater compared with the pedicle side.

Deep Inferior Epigastric Perforators Topography for "Island Transverse Rectus Abdominis Musculocutaneous Flap" in Breast Reconstruction

Background  The Island transverse rectus abdominis musculocutaneous (TRAM) flap is well vascularized with very reliable blood flow, because all perforators of the zone I are included when it is harvested. The number of perforators, topographic mapping, and their relationship with reconstructed outcomes were investigated. Methods  Fifty patients with Island TRAM breast reconstruction from September 2021 to August 2022 were investigated. The zone I was divided into a total of eight sections. Under the loupe magnification, all perforators larger than 0.5 mm in zone I were counted with fine dissection, and photographs were taken in background of vessel loops. Complications like flap necrosis, seroma, and hematoma were also investigated. Result  There are 12 ideal perforators on average in zone I such as one perforator in section I, II, IV, V, VI, VIII, and three perforators in section III and VII. However, two perforators (M6 and L6) below arcuate line were sacrificed in the time of flap harvest to prevent hernia. Island TRAM included 10 perforators on average (5 perforators in each side) above arcuate line to be transferred to the recipient site. Only minor complications were identified. Conclusion  The Island TRAM flap includes 10 perforators to get the vigorous blood flow. The periumbilical to upper medial perforators become more dominant in the perfusion of the flap after deep inferior epigastric artery division. Well preserved perforators will guarantee the satisfactory breast reconstruction with the least complication.

Near-infrared fluorescence angiography with indocyanine green for perfusion assessment of DIEP and msTRAM flaps: A Dutch multicenter randomized controlled trial

Background

A common complication after a DIEP flap reconstruction is the occurrence of fat necrosis due to inadequate flap perfusion zones. Intraoperative identification of ischemic zones in the DIEP flap could be optimized using indocyanine green near-infrared fluorescence angiography (ICG-NIR-FA). This randomized controlled trial aims to determine whether intraoperative ICG-NIR-FA for the assessment of DIEP flap perfusion decreases the occurrence of fat necrosis.

Design/methods

This article describes the protocol of a Dutch multicenter randomized controlled clinical trial: the FAFI-trial. Females who are electively scheduled for autologous breast reconstruction using DIEP or muscle-sparing transverse rectus abdominis muscle (msTRAM) flaps are included. A total of 280 patients will be included in a 1:1 ratio between both study arms. In the intervention arm, the intraoperative assessment of flap perfusion will be based on both regular clinical parameters and ICG-NIR-FA. The control arm consists of flap perfusion evaluation only through the regular clinical parameters, while ICG-NIR-FA images are obtained during surgery for which the surgeon is blinded. The main study endpoint is the difference in percentage of clinically relevant fat necrosis between both study arms, evaluated two weeks and three months after reconstruction.

Conclusion

The FAFI-trial, a Dutch multicenter randomized controlled clinical trial, aims to investigate the clinical added value of intraoperative use of standardized ICG-NIR-FA for assessment of DIEP/msTRAM flap perfusion in the reduction of fat necrosis.

Clinical trial registration number

NCT05507710; NL 68623.058.18.

Evidence based recommendations for perioperative vasopressor use and fluid resuscitation in microsurgery

Blood pressure regulation is critical in patients undergoing microsurgical free tissue transfer; however, guidelines for addressing and preventing perioperative hypotension remain highly debated, with two current thought paradigms: (1) intravenous fluid administration with a balanced salt solution (e.g., lactate ringer and normal saline) and/or colloid (e.g., albumin) and (2) vasoactive pharmacological support with vasopressors (e.g., dobutamine, norepinephrine, epinephrine), with fluid administration being the preferred conventional approach. Here, we review the most up to date available literature and summarize currents perspectives and practices for fluid resuscitation and vasopressor use, while offering evidence-based guidelines to each.

Effect of sevoflurane-remifentanil and propofol-remifentanil anesthesia on glycocalyx shedding during deep inferior epigastric perforator flap breast reconstruction: a prospective randomized, controlled trial

BACKGROUND

The endothelial glycocalyx (EG) is an important structure that regulates vascular homeostasis. Deep inferior epigastric perforator (DIEP) flap is expected to cause substantial EG breakdown owing to the long procedural duration and ischemia- reperfusion injury. This prospective, randomized, controlled study aimed to compare syndecan-1 levels during sevoflurane-remifentanil and propofol-remifentanil anesthesia in patients who underwent DIEP flap breast reconstruction.

METHODS

Fifty-one patients were randomized to either sevoflurane (n = 26) or propofol (n = 25) groups. Anesthesia was maintained with remifentanil in combination with either sevoflurane or propofol. The primary endpoint was the concentration of serum syndecan-1 measured at 1 h after surgery.

RESULTS

Fifty patients (98.0%) completed the study. Patients in the propofol group had significantly lower levels of syndecan-1 than patients in the sevoflurane group at 1 h after operation (23.8 ± 1.6 vs. 30.9 ± 1.7 ng/ml, respectively; Bonferroni corrected P = 0.012). There were no significant differences between groups in postoperative complications. The postoperative hospital stay was 8.4 ± 2.5 days in the sevoflurane group and 7.4 ± 1.0 days in the propofol group (P = 0.077).

CONCLUSIONS

Propofol-remifentanil anesthesia resulted in lesser increases in syndecan-1 levels compared to increases with sevoflurane-remifentanil anesthesia in patients who underwent DIEP flap reconstruction. Our results suggest that propofol-remifentanil anesthesia shows protective effects against EG damage during DIEP flap breast reconstruction in contrast to sevoflurane-remifentanil anesthesia.

The Role of Measurement of Pedicle Length for DIEP Flap Transferring in Breast Reconstruction: A Single-Center, Open-Label, Randomized Controlled Trial

BACKGROUND

Intraoperative venous congestion is a main complication in deep inferior epigastric artery perforator (DIEP) flap for breast reconstruction. We present a pedicle measuring technique to precisely predict the length of pedicle needed in DIEP free flap, to improve the outcome, and to reduce the risk of donor site morbidity and complications.

MATERIALS AND METHODS

A single-center, open-label, prospective, randomized study was carried out to access efficacy and safety of a pedicle measuring technique in 389 patients. Each patient received a delayed breast reconstruction using free unipedicled DIEP flap, and internal mammary vessels were chosen as recipient vessels. During the surgery, the conventional DIEP flap technique was used in the control group, in which the course of the pedicle was fully dissected. In the measuring group, the flap in setting way was decided preoperatively, the distance (A) between the internal mammary vessels (a) and the point of DIEP perforator into the subcutaneous tissue (b) was measured, and then the length (B) of the perforator (c) and the main trunk (d) is measured and dissected to achieve 1 cm longer than A.

RESULTS

There are 180 and 209 patients enrolled in the control and measuring group, respectively. Venous congestion occurred in 15 patients (8.3%) in the control group, and 1 patient (0.5%) in the measuring group ( P < 0.001). All the 16 patients were found venous thrombosis. Then successful free flap salvage surgeries were performed in 10 patients. Six patients (3.3%) had total flap necrosis due to recurrent venous thromboembolisms. Fat necrosis occurred in 16 patients (8.9%) in the control group, and 5 patients (2.4%) in the measuring group ( P = 0.006). Partial flap necrosis was found in 12 patients (6.7%) in the control group, and in 3 patients (1.4%) in the measuring group ( P = 0.008). Total flap necrosis occurred in 6 patients (3.3%) in the control group, but no (0%) patient in the measuring group ( P = 0.009).

CONCLUSIONS

Measurement of pedicle length for DIEP flap transferring in breast reconstruction is a reliable technique that could secure the DIEP free flap, reduce operative invasiveness, and lower the risk of complications considerably.

Deep Inferior Epigastric Perforator Flap for Immediate Breast Reconstruction following Mastectomy in Breast Cancer Patients: An Initial Experience in Vietnam

Background

Breast reconstruction in breast cancer patients is an optional surgery that improves the quality of life while preserving the efficacy of chemotherapy and radiotherapy. Deep inferior epigastric perforator (DIEP) flap is a new but reliable and safe technique for autologous breast reconstruction. After mastectomy, immediate reconstruction is the preferred method because of its aesthetic result and convenience. This study is aimed at summarizing our experience in DIEP flap for immediate breast reconstruction.

Methods

A prospective study was performed on 30 breast cancer patients who underwent intermediate breast reconstruction for DIEP flap after mastectomy from June 2019 to June 2021 in Hanoi Medical University Hospital. Clinicopathology characteristics, tumor stage, treatment, and complications were evaluated.

Result

The mean age of patients was 44.9 (range: 29-73 years). 86.7% of patients were in stages I and II. Five patients (16.7%) received neoadjuvant chemotherapy. 20 patients (66.7%) underwent nipple-sparing mastectomy (NSM) procedures. The mean operating time was 341 minutes. The mean time to receive chemotherapy was 34.68 days. The mean number of perforators was 1.30. The overall flap success rate was 90%. Twelve patients (40%) experienced complications. Four patients (13.3%) returned to the operating room due to venous congestions. Two patients (6.67%) had complete flap loss. Other complication: fat necrosis (6.7%), seroma (13.3%), partial flap loss (3.3%), abdominal wound dehiscence (6.7%), pneumonia (3.3%), and pulmonary embolism (6.7%). After one-month postoperation, 88.9% of patients were satisfied with their breasts, and 74.07% were satisfied with the operation.

Conclusion

DIEP flap is a new but reliable and safe technique for autologous breast reconstruction. Though patients opting for breast reconstruction still have a low risk of complication and reconstruction failure, this procedure should be used more frequently in appropriate patients to improve their quality of life.

The Anatomic Features and Role of Superficial Inferior Epigastric Vein in Abdominal Flap

In lower abdominal flap representing transverse rectus abdominis musculocutaneous (TRAM) flap or deep inferior epigastric perforator (DIEP) flap, superficial inferior epigastric vein (SIEV) exists as superficial and independent venous system from deep system. The superficial venous drainage is dominant despite a dominant deep arterial supply in anterior abdominal wall. As TRAM or DIEP flaps began to be widely used for breast reconstruction, venous congestion issue has been arisen. Many clinical series in regard to venous congestion despite patent microvascular anastomosis site were reported. Venous congestion could be divided in two conditions by the area of venous congestion and each condition is from different anatomical causes. First, if venous congestion was shown in whole flap, it is due to the connection between SIEV and vena comitantes of DIEP. Second, if venous congestion is limited in above midline (Hartrampf zone II), it is due to problem in venous midline crossover. In this article, the authors reviewed the role of SIEV in lower abdominal flap based on the various anatomic and clinical studies. The contents are mainly categorized into four main issues; basic anatomy of SIEV, the two cause of venous congestion, connection between SIEV and vena comitantes of DIEP, and midline crossover of SIEV.

The Impact of Indocyanine Green Angiography on Fat Necrosis in Deep Inferior Epigastric Perforator Flap Breast Reconstruction

BACKGROUND

The deep inferior epigastric perforator flap (DIEP) is a widely known reliable option for autologous breast reconstruction. One common complication of DIEP procedures is fat necrosis. Consequences of fat necrosis include wound healing complications, pain, infection, and the psychological distress of possible cancerous recurrence. Clinical judgment alone is an imperfect method to detect at-risk segments of adipose tissue. Objective methods to assess perfusion may improve fat necrosis complication rates, reducing additional surgeries to exclude cancer and improve cosmesis for patients.

METHODS

The authors performed a retrospective review of patients who underwent analysis of DIEP flap vascularity with or without intraoperative indocyanine green angiography (ICGA). Flap perfusion was assessed using intravenous ICGA and was quantified with both relative and absolute value units of fluorescence. Tissue with observed values less than 25% to 30% relative value units was resected. Postoperative outcomes and fat necrosis incidence were collected.

RESULTS

Three hundred fifty-five DIEP flaps were included in the study, 187 (52.7%) of which were assessed intraoperatively with ICGA. Thirty-nine patients (10.9%) experienced operable fat necrosis. No statistically significant difference in incidence of postoperative fat necrosis was found between the 2 groups (P = 0.732). However, a statistically significant relationship was found between fat necrosis incidence and body mass index as both a continuum (P = 0.001) and when categorized as greater than 35 (P = 0.038).

CONCLUSIONS

Although ICGA is useful for a variety of plastic surgery procedures, our retrospective review did not show a reduction in operable fat necrosis when using this technology.

Standardization of the Rat Dorsal Random Pattern (McFarlane) Flap Model and Evaluation of the Pharmacological Agents Aiming to Salvage Partial Flap Necrosis: A Systematic Review and a Meta-analysis

INTRODUCTION

Partial flap necrosis is a common complication after surgery. McFarlane flap model has been used for assessment of various agents' effects on random flap survival. The aim of this study was to review the methodology of studies using this flap model and reveal the most successful agents.

MATERIALS AND METHODS

PubMed, Scopus, and Web of Science databases were screened for words "McFarlane flap," "flap survival," and ("flap" and "rat") by using time limits between 1965 and 2019. A total of 71 original articles were reviewed. Dimensions and base (cranial/caudal) of the flap, treatment protocol, follow-up period, and survival rates were extracted. Modified survival rates were calculated. Coefficients of variation of cranial/caudally based control group flaps and most commonly used flap models were calculated to assess interstudy variability.

RESULTS

A total of 165 different treatment regimens were studied. One-hundred twelve regimens (67.9%) were found to increase flap survival. Most common flap dimensions were 9 cm × 3 cm, followed by 10 cm × 3 cm, 8 cm × 2 cm and 6 cm × 2 cm. Studies using caudally based flaps showed less interstudy variability, but survival rates were similar. Pentoxifylline, sildenafil, chlorpromazine, phenoxybenzamine, and phentolamine were reported to be successful in multiple studies.

CONCLUSIONS

There are numerous agents found to be effective for treatment of partial flap necrosis, but further clinical research is needed. To overcome standardization problems, use of commonly used flap dimensions with a caudal base and interpretation of results after 7 days of follow-up seems appropriate.

Assessment of deep inferior epigastric perforator flap perfusion with near-infrared fluorescence: A pilot study and description of a standardized working protocol

Fat necrosis (FN) is a common complication after autologous breast reconstruction (ABR) using a free flap, which can influence reconstruction outcome and patient satisfaction. Intraoperative near-infrared fluorescence imaging using indocyanine green (ICG) permits the visualization of flap perfusion. The aim of this study was to assess the effect of near-infrared fluorescence on FN incidence in patients undergoing an ABR with a deep inferior epigastric perforator flap (DIEP) and to propose a standard working protocol for this technique. In this prospective study, patients undergoing one-sided ABR with a DIEP were included. The standard DIEP procedure was complemented with near-infrared fluorescence imaging using the fluorescent tracer ICG to evaluate flap perfusion. This cohort was compared to a retrospective cohort of DIEP procedures without near-infrared fluorescence imaging. Patients and surgery characteristics, as well as postoperative complications, were registered and compared. In both cohorts, 24 patients were included. No significant differences were present between patients and surgery characteristics, including no difference in duration of surgery. In the prospective and retrospective group, the incidence of FN was 4.2% and 33%, respectively (p-value = 0.023). Moreover, microsurgeons were positive about using near-infrared fluorescence as it either provided additional information about perfusion or confirmed the clinical assessment. Our pilot study showed a significant decrease of FN in patients undergoing an ABR with a DIEP when near-infrared fluorescence imaging was used to assess flap perfusion. This study provides a standardized working protocol for near-infrared fluorescence imaging. In the future, large multicenter studies should focus on the quantification of near-infrared fluorescence imaging.

Validating machine learning approaches for prediction of donor related complication in microsurgical breast reconstruction: a retrospective cohort study

Autologous reconstruction using abdominal flaps remains the most popular method for breast reconstruction worldwide. We aimed to evaluate a prediction model using machine-learning methods and to determine which factors increase abdominal flap donor site complications with logistic regression. We evaluated the predictive ability of different machine learning packages, reviewing a cohort of breast reconstruction patients who underwent abdominal flaps. We analyzed 13 treatment variables for effects on the abdominal donor site complication rates. To overcome data imbalances, random over sampling example (ROSE) method was used. Data were divided into training and testing sets. Prediction accuracy, sensitivity, specificity, and predictive power (AUC) were measured by applying neuralnet, nnet, and RSNNS machine learning packages. A total of 568 patients were analyzed. The supervised learning package that performed the most effective prediction was neuralnet. Factors that significantly affected donor-related complication was size of the fascial defect, history of diabetes, muscle sparing type, and presence or absence of adjuvant chemotherapy. The risk cutoff value for fascial defect was 37.5 cm². High-risk group complication rates analyzed by statistical method were significant compared to the low-risk group (26% vs 1.7%). These results may help surgeons to achieve better surgical outcomes and reduce postoperative burden.

Setting up a new microsurgical breast service in a non-tertiary hospital: Is it safe, and do outcomes compare to centres of excellence?

AIMS

Access to autologous reconstruction continues to be limited in some areas of the United Kingdom. This is, in part, due to the perceived difficulty offering this service outside of a large tertiary centre. We present our experience setting up a new microsurgical breast reconstruction service in a district hospital and compare our results to the published outcomes of large volume centres.

METHODS

Patient data were collected prospectively from the start of the service to date (July 2018- July 2020) with the capture of demographics, management, and outcomes. The BREAST-Q tool was used preoperatively and at a minimum of 3 months.

RESULTS

The first 40 patients undergoing DIEP reconstruction were included. Of these, 70% were immediate, mean age was 49 years (27-68) and BMI was 28.1 kg/m2 (22-32.5). In all, 50% had one or more co-morbidities other than breast cancer. Median length of stay was 3 days (2-6) with 75% of patients discharged on day 2 or 3. Ten patients' stay exceeded 3 days - mostly due to social reasons. Flap loss occurred in 1 patient (2.5%). Twenty-one patients developed complications (52%) within 90 days: seven Clavien-Dindo Grade I, two Grade II and ten Grade IIIb. Fat necrosis and mastectomy flap necrosis were the most common complications. Surgical intervention was higher in those needing adjuvant therapy. Patient-reported outcomes showed post-operative improvement across all domains except abdominal physical well-being at median 11.3 months.

CONCLUSIONS

We present the shortest published length of stay for unilateral DIEP reconstructions. We are the first paper to publish patient-reported outcomes following a breast microsurgical enhanced recovery protocol. We demonstrate how a new microsurgical service, utilising an enhanced recovery protocol and careful patient selection can immediately achieve outcomes comparable to well-established centres. There is no reason why all patients should not have access to microsurgical breast reconstruction locally.

Hypofractionated versus conventional fractionated radiotherapy for breast cancer in patients with reconstructed breast: Toxicity analysis

PURPOSE

This study investigated whether hypofractionated adjuvant radiotherapy (RT) increased breast-related complication(s) compared to conventional fractionated RT in reconstructed breast cancer patients.

METHODS

We conducted a retrospective review including 349 breast cancer patients who underwent immediate breast reconstruction following mastectomy or breast-conserving surgery (BCS) between 2009 and 2018 at two institutions. All patients were treated with adjuvant RT via either a conventional fractionated or hypofractionated regimen. We defined a major breast complication as a breast-related toxic event requiring re-operation or re-hospitalization during the follow-up period after the end of RT.

RESULTS

The median follow-up was 32.3 months (4.8-118.5 months); 126 patients had conventional fractionated RT, and 223 patients received hypofractionated RT. In patients with mastectomy, there was no significant difference in the occurrence of any or major breast-related complications between the two fractionation regimens. In patients undergoing BCS, incidence of any breast complication showed no difference between two RT groups and no major breast complication was reported as well. Hypofractionated RT did not increase major wound problem (infection and dehiscence) compared to conventional RT. Incidence of major contracture was significantly lower in hypofractionated RT.

CONCLUSIONS

There was no significant difference in the occurrence of any or major breast-related complications between the two different fractionation regimens, even in patients with mastectomy. Hypofractionated RT may be used comparable to conventional fractionated RT in terms of breast-related complications in reconstructed breast cancer patients. The prospective randomized trial would be necessary to clarify this issue.

Effect of intravenous lidocaine on ischemia-reperfusion injury in DIEP microsurgical breast reconstruction. A prospective double-blind randomized controlled clinical trial

BACKGROUND

Ischemia-reperfusion injury in free flaps is associated with tissue damage and is one of the main factors causing flap failure in reconstructive microsurgery. The aim of this study is to assess whether any ischemia-reperfusion injury takes place during a microsurgical flap reconstruction as seen through the levels of malondialdehyde (MDA) and superoxide dismutase, biomarkers of oxidative stress, and to analyze the effect of lidocaine in this process.

METHODS

Twenty-four patients operated for immediate breast reconstruction using the Deep Inferior Epigastric Perforator free flap technique were divided into two groups: one group was treated with a lidocaine intravenous perfusion and the other group with a saline perfusion. MDA and superoxide dismutase (SOD) levels were measured at several points before, during, and after surgery.

RESULTS

There was an increase in MDA levels in both groups, but the lidocaine group experienced a decrease during reperfusion. On the other hand, we observed a rise in SOD levels in both groups, but a decrease during reperfusion in the placebo group. However, these differences between groups were not statistically significant.

CONCLUSIONS

The decreased SOD activity and increased MDA content in our research prove a redox imbalance and high reactive oxygen species levels in flaps, indicating that tissues experience ischemia-reperfusion injury during microsurgical reconstruction. Lidocaine may have a protective effect in free flap surgery, but our results were not statistically significant, so further studies will be required.

Differences of the midline-crossing venous drainage pattern in supraumbilical and infraumbilical regions: Angiographic study using fresh cadavers

Current clinical and anatomical studies show that the venous problem associated with the deep inferior epigastric perforator flap results from poor midline-crossing. We examined the venous anatomy of the infraumbilical midline area and the dynamic venous flow of the deep inferior epigastric perforator flap in nine fresh cadavers. All nine abdominal specimens were harvested between the subcostal margin and the groin crease. Two specimens were used to analyze the abdominal venous anatomy, one of which was divided into two hemi-abdominal specimens. The remaining seven specimens were harvested as deep inferior epigastric perforator flaps with one major paraumbilical perforator. Venous cannulation and serial angiographic agent injection were performed in several conditions. Each specimen was radiographed using a soft X-ray system. For additional information, computed tomography (CT) angiography-visualized superficial inferior epigastric veins (SIEVs) and the supraumbilical branch were analyzed. We noted that the venous drainage between the bilateral SIEVs was easier to configure in the supraumbilical area than in the infraumbilical area. Only one to two short polygonal venous networks connect the bilateral superficial inferior epigastric veins in the supraumbilical area; however, long and multiple polygonal venous networks connect the bilateral superficial inferior epigastric veins in the infraumbilical area, which could be a predisposing factor for venous congestion. The mean distance from the umbilicus upper border to evident supraumbilical midline crossover was 18.39±4.03 mm (range: 10.10–28.49) in CT angiograms. In cadaver specimens, the mean distance was 10.87±4.85 mm (range: 4.6–18.9). Supraumbilical midline crossover was more favorable than infraumbilical midline crossover in venous flow.

Meta-analysis of the effects of venous super-drainage in deep inferior epigastric artery perforator flaps for breast reconstruction

INTRODUCTION

Venous congestion is the most common vascular complication of the deep inferior epigastric artery perforator (DIEP) flaps. Adding a second venous drainage by anastomosing a flap vein and a recipient vein (super-drainage) is considered the solution of choice. Evidence to support this procedure, had not yet been confirmed by an analysis of the literature. We aimed to provide this evidence.

MATERIALS AND METHODS

We searched the literature (MedLine, Scopus, EMBASE, Cochrane Library, and Google Scholar), for studies discussing venous congestion and venous super-drainage in DIEP flap for breast reconstruction. Thirteen of the 35 articles compared results between one or two venous anastomoses. Meta-analysis was performed following PRISMA guidelines. Pooled risk ratio (RRs) for congestion, fat necrosis, partial necrosis, and total necrosis with corresponding 95% confidence intervals (CI) were calculated using a fixed-effect model with the Mantel-Haenszel method. The need to return to surgery (95% CI) was estimated with a random effect model using the DerSimonian and Liard method.

RESULTS

We showed a statistically significant advantage of super-drainage to reduce the venous congestion of the flap (RR: 0.12, 95% CI: 0.04-0.34, p-value <.001), partial flap necrosis (RR: 0.50, 95% CI: 0.30-0.84, p-value .008), total flap necrosis (RR: 0.31, 95% CI: 0.11-0.85, p-value .023), and the need to take the patient back to surgery for perfusion-related complications (RR: 0.45, 95% CI: 0.21-0.99, p value .048).

CONCLUSIONS

Performing a second venous anastomosis between the SIEV and a recipient vein (venous superdrainage) reduces venous congestion and related complications in DIEP flaps for breast reconstruction.

Fat Necrosis After DIEP Flap Breast Reconstruction: A Review of Perfusion-Related Causes

INTRODUCTION

Fat necrosis is a common complication for the deep inferior epigastric perforator (DIEP) flap. A thorough understanding of the factors associated with fat necrosis will aid operative planning for reconstructive surgeons.

METHODS

A systematic review of the literature was performed between January 1989 and April 2019. Studies were included if they reported on fat necrosis in DIEP flap or evaluated the perfusion of the DIEP flap. Twenty-eight out of 312 studies met the inclusion and exclusion criteria.

RESULTS

Fat necrosis rates ranged from 12.0 to 45.0% on clinical examination within the literature. The four main perforator-specific factors identified included perforator perfusion zones, perforator location, perforator number and venous congestion. Medial row perforators have a wider perfusion zone, while lateral row perforators have a narrow perfusion zone. Holm zone III has a higher rate of fat necrosis compared to Holm zone II. One to two perforators and more than five perforators and a Type III atypical connection between the superficial and deep venous system had a higher rate of fat necrosis.

CONCLUSION

The DIEP flap should incorporate between two and three perforators of a substantial calibre; Holm zone III should be excluded if able and careful review of the pre-operative imaging should be performed to analyse the connections between the deep and superficial venous system. There are multiple perfusion-related factors to consider when planning the DIEP flap and ultimately a patient-specific approach to the vascular anatomy is essential.

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 .

Different Hydraulic Constructs to Optimize the Venous Drainage of DIEP Flaps in Breast Reconstruction: Decisional Algorithm and Review of the Literature

BACKGROUND

 Venous congestion is the most common perfusion-related complication of deep inferior epigastric artery perforator (DIEP) flap. Several hydraulic constructs can be created for venous superdrainage in case of flap venous engorgement or as a preventive measure. These can be classified based on the choice of the draining vein of the flap, either a second deep inferior epigastric vein (DIEV) or a superficial inferior epigastric vein (SIEV), and of the recipient vein, either a vein of the chest or the DIEV.

METHODS

 We conducted a comprehensive systematic literature review in Medline, Scopus, EMBASE, Cochrane Library, and Google Scholar to find publications that reported on venous congestion in DIEP flap. The keywords used were DIEP Flap, breast reconstruction, venous congestion, supercharging, superdrainage, SIEV, and DIEV.

RESULTS

 Based on the studies found in the literature, we developed an algorithm to guide the surgeon's decision when choosing the veins for the superdrainage anastomosis.

CONCLUSION

 Several alternatives for venous anastomosis in superdrainage are available. We propose an algorithm to simplify the choice. The use of the ipsilateral SIEV to be connected to a vein of the chest appears to be advantageous. The anatomical position that allows the easiest anastomosis dictates which chest vein to favor.

Immediate and delayed autologous abdominal microvascular flap breast reconstruction in patients receiving adjuvant, neoadjuvant or no radiotherapy: a meta-analysis of clinical and quality-of-life outcomes

BACKGROUND

Effects of postmastectomy radiotherapy (PMRT) on autologous breast reconstruction (BRR) are controversial regarding surgical complications, cosmetic appearance and quality of life (QOL). This systematic review evaluated these outcomes after abdominal free flap reconstruction in patients undergoing postoperative adjuvant radiotherapy (PMRT), preoperative radiotherapy (neoadjuvant radiotherapy) and no radiotherapy, aiming to establish evidence-based optimal timings for radiotherapy and BRR to guide contemporary management.

METHODS

The study was registered on PROSPERO (CRD42017077945). Embase, MEDLINE, Google Scholar, CENTRAL, Science Citation Index and ClinicalTrials.gov were searched (January 2000 to August 2018). Study quality and risk of bias were assessed using GRADE and Cochrane's ROBINS-I respectively.

RESULTS

Some 12 studies were identified, involving 1756 patients (350 PMRT, 683 no radiotherapy and 723 neoadjuvant radiotherapy), with a mean follow-up of 27·1 (range 12·0-54·0) months for those having PMRT, 16·8 (1·0-50·3) months for neoadjuvant radiotherapy, and 18·3 (1·0-48·7) months for no radiotherapy. Three prospective and nine retrospective cohorts were included. There were no randomized studies. Five comparative radiotherapy studies evaluated PMRT and four assessed neoadjuvant radiotherapy. Studies were of low quality, with moderate to serious risk of bias. Severe complications were similar between the groups: PMRT versus no radiotherapy (92 versus 141 patients respectively; odds ratio (OR) 2·35, 95 per cent c.i. 0·63 to 8·81, P = 0·200); neoadjuvant radiotherapy versus no radiotherapy (180 versus 392 patients; OR 1·24, 0·76 to 2·04, P = 0·390); and combined PMRT plus neoadjuvant radiotherapy versus no radiotherapy (272 versus 453 patients; OR 1·38, 0·83 to 2·32, P = 0·220). QOL and cosmetic studies used inconsistent methodologies.

CONCLUSION

Evidence is conflicting and study quality was poor, limiting recommendations for the timing of autologous BRR and radiotherapy. The impact of PMRT and neoadjuvant radiotherapy appeared to be similar.

Development and Evaluation of a Machine Learning Prediction Model for Flap Failure in Microvascular Breast Reconstruction

BACKGROUND

Despite high success rates, flap failure remains an inherent risk in microvascular breast reconstruction. Identifying patients who are at high risk for flap failure would enable us to recommend alternative reconstructive techniques. However, as flap failure is a rare event, identification of risk factors is statistically challenging. Machine learning is a form of artificial intelligence that automates analytical model building. It has been proposed that machine learning can build superior prediction models when the outcome of interest is rare.

METHODS

In this study we evaluate machine learning resampling and decision-tree classification models for the prediction of flap failure in a large retrospective cohort of microvascular breast reconstructions.

RESULTS

A total of 1012 patients were included in the study. Twelve patients (1.1%) experienced flap failure. The ROSE informed oversampling technique and decision-tree classification resulted in a strong prediction model (AUC 0.95) with high sensitivity and specificity. In the testing cohort, the model maintained acceptable specificity and predictive power (AUC 0.67), but sensitivity was reduced. The model identified four high-risk patient groups. Obesity, comorbidities and smoking were found to contribute to flap loss. The flap failure rate in high-risk patients was 7.8% compared with 0.44% in the low-risk cohort (p = 0.001).

CONCLUSIONS

This machine-learning risk prediction model suggests that flap failure may not be a random event. The algorithm indicates that flap failure is multifactorial and identifies a number of potential contributing factors that warrant further investigation.

The island-type pedicled TRAM flap: Improvement of the aesthetic outcomes of breast reconstruction

BACKGROUND

The pedicled transverse rectus abdominis myocutaneous flap (TRAM) remains an effective and widely-used method for breast reconstruction despite well-documented donor-site morbidity. We present the island-type pedicled TRAM flap as a way to obtain better and more reliable outcomes in breast reconstruction.

METHODS

A retrospective chart review of patients who underwent breast reconstruction with an island-type pedicled TRAM flap was performed. Patient demographics and complications were reviewed. In the island-type pedicled TRAM flap, we transversely resected the upper ipsilateral rectus muscle surrounding the origin of the superior epigastric vessels, preserving only a 1-cm muscle strip including the vascular pedicle to prevent epigastric bulging and inframammary fold (IMF) disruption. The flap was turned over into the ipsilateral breast pocket. The IMF was repaired except for the portion where the pedicle was placed.

RESULTS

From January 2013 to November 2017, 88 patients underwent surgery using the island-type pedicled TRAM flap. The etiology of the defect was breast cancer with mastectomy in 86 cases, and paraffinoma in two cases. Seventy-seven patients underwent unilateral reconstruction, and 11 patients underwent bilateral reconstruction. Minor fat necrosis occurred in eight cases. Mild inframammary or epigastric bulging was observed in five cases, and neither partial nor total flap necrosis was observed. The aesthetic outcome of the IMF was evaluated in 55 cases, and 53 cases received good overall scores.

CONCLUSION

Although the island-type pedicled TRAM flap is technically challenging because careful dissection and pedicle identification is required, it can provide more reliable and better aesthetic results without an increased risk of vascular compromise.

Comparison of the viscoelastic properties of human abdominal and breast adipose tissue and its incidence on breast reconstruction surgery. A pilot study

BACKGROUND

Breast cancer is the leading malignant tumor in women in the world. Reconstruction after mastectomy plays a key role in the physical and psychological recuperation, being the abdominal skin and adipose tissue the best current option for the DIEP surgery. The aim of the surgery is to obtain a reconstructed breast which looks and behaves naturally. Therefore, it would be useful to characterize the mechanical behaviour of the adipose tissue in the abdomen and breast to compare their mechanical properties, also investigating possible regional differences.

METHODS

Experimental tests have been carried out in breast and abdominal adipose tissue samples, obtaining their viscoelastic properties. The specimens have been subjected to uniaxial compression relaxation tests and a mechanical behaviour model has been fitted to the experimental curves. Afterwards, statistical analyses have been used to detect differences between different individuals' abdominal fat tissue and finally between different areas of the same individual's breast and abdominal adipose tissue.

FINDINGS

Several conclusions could be extracted from the results: 1) inter-individual differences may exist in the abdominal adipose tissue; 2) the breast fat could be regarded as a unique tissue from the mechanical point of view; 3) significant differences were detected between the superficial breast and all the locations of the abdomen, except for the superficial lateral one and 4) the mechanical properties of the abdominal adipose tissue seem to change with the depth. These conclusions can be of great value for DIEP surgeries and other surgeries in which the adipose tissue is involved.

Deep Inferior Epigastric Artery Perforator Flap Breast Reconstruction in Women With Previous Abdominal Incisions: A Comparison of Complication Rates

BACKGROUND

The deep inferior epigastric artery perforator (DIEP) flap is currently the most widely used method for autologous microsurgical breast reconstruction. There are mixed data in the literature regarding the impact of previous abdominal surgery on DIEP flap success in breast reconstruction. With this study, we take a closer look at the effect of prior abdominal surgery on DIEP flap and donor-site complications, with a particular focus on the different types of incisions and their influence on surgical outcomes.

METHODS

A retrospective cohort study was conducted over a 6-year period. Five hundred forty-four consecutive DIEP flaps were divided into a control group (321 flaps) without previous abdominal surgery and an incision group (223 flaps) with previous abdominal surgery. A comparison between both groups was made in terms of flap and donor-site complications followed by a subgroup analysis based on single types of abdominal incisions.

RESULTS

There were no significant differences between both groups in terms of age, body mass index, flap weight, smoking history, prior radiotherapy, diabetes, and coagulopathy (P > 0.05). The most common incision was low transverse incision (n = 116) followed by laparoscopy port (n = 103) and midline (n = 46) incisions. We found no significant differences between the control group and incision group in terms of flap complications. Subgroup analysis revealed that none of the 3 types of incision increase the flap or donor-site complications. Smoking and flap weight were the only 2 independent predictors for donor-site complications.

CONCLUSIONS

The results from this large series of consecutive DIEP flaps from our institution confirm that autologous breast reconstruction with DIEP flap can be safely performed in patients who have had previous abdominal surgeries; however, counseling patients about smoking is critical to avoid potential donor-site complications.

How should we manage women with fat necrosis following autologous breast reconstruction: An algorithmic approach

Fat necrosis is a common complication of autologous breast reconstruction; however, diagnostic criteria are yet to be standardized, making comparison of autologous breast reconstructive techniques challenging. A systematic review found six of 556 articles met inclusion criteria. These results were used to generate an algorithm for managing fat necrosis after autologous breast reconstruction.

Incidental finding of subclavian artery occlusion and subsequent hypoplastic internal mammary artery as a candidate recipient vessel in DIEP flap breast reconstruction

We report a case of autologous breast reconstruction in which a thoracodorsal vessel was used as a recipient vessel after a hypoplastic internal mammary vessel was found on preoperative computed tomography (CT) angiography. A 46-year-old woman with no underlying disease was scheduled to undergo skin-sparing mastectomy and breast reconstruction using a deep inferior epigastric artery perforator flap. Preoperative CT angiography showed segmental occlusion of the right subclavian artery with severe atherosclerosis and calcification near the origin of the internal mammary artery, with distal flow maintained by collateral branches. The thoracodorsal artery was selected to be the recipient vessel because CT showed that it was of adequate size and was not affected by atherosclerosis. The patient experienced no postoperative complications, and the flap survived with no vascular complications. The breasts were symmetrical at a 6-month follow-up. This case highlights that preoperative vascular imaging modalities may help surgeons avoid using diseased vessels as recipient vessels in free flap breast reconstructions.

[Complications of autologous breast reconstruction]

Flap reconstruction techniques are increasingly desired by French's patients and it represents almost half of breast reconstruction indications in 2017. The main reasons of this statistics are the growing concerns of the patients with breast implant of developing BIA-ALCL, as well as their desire of having a more natural reconstruction results without having any foreign bodies. The multiplication of autologous reconstruction techniques, especially microsurgical techniques which has been popularized in the recent years, makes possible to propose a reconstruction to the majority of patients without an implant. This type of reconstructions is associated with a significant number of complications; thus, a proper selection of patient should be done and a good knowledge of the surgical technique by the surgeon to reduce the complication. Our proposed study is divided into two main parts, the complications of the flap and the complications at the donor site. Based on the experience of our plastic surgery department in immediate and delayed breast reconstruction, the objective of this article is to describe and to analyze the possible complications of breast reconstruction by a flap and their surgical management in intra and post operatively. Our goal is to provide an algorithm for our young colleagues in order to obtain better understanding of this type of interventions difficulties and to provide an appropriate care in the event of complication, also to provide optimal care to the patients who wish to undergo autologous flap reconstructions.

Experimental study of pedicled subcostal artery perforator (SCAP) flap: A new application in breast reconstruction

BACKGROUND

Latissimus dorsi flap is the gold standard for pedicled breast reconstruction but is limited by donor site scarring, which is difficult to conceal, and a high rate of post-operative seroma. We investigated the anatomic characteristics and feasibility of using a subcostal artery perforator (SCAP) flap, which was taken from the flank area and vascularised by a perforator artery through a subcostal pedicle, for a breast reconstruction.

METHODS

A literature review was undertaken to determine the anatomy of the SCAP flap pedicle and the vascular supply to this dermal-fat flap. Pedicled SCAP flaps were dissected on cadavers to identify the anatomy of the perforator arteries and the pedicle length. Pedicled SCAP flaps were then tunnelled through the chest area to evaluate their feasibility for breast reconstruction.

RESULTS

Twelve SCAP flaps were prepared on six cadavers. Mean pedicle length was 17 cm (14.5-20 cm). Mean flap size was 13 × 18 cm (11.5 × 15.5-15 × 21 cm). For each flap, a pedicle of sufficient length was dissected to allow the tunnelling of the flap and to perform breast reconstruction with a dermal-fat flap of adequate size. In all cases, an SCAP flap was prepared, without taking muscle, to reduce the risk of parietal complications at the donor site in future clinical applications.

CONCLUSION

Pedicled SCAP flap is a feasible option in breast reconstruction and could represent a less arduous surgical alternative to free flaps for some patients. Donor site scarring was acceptable. Clinical application of SCAP flaps should be investigated further.

A Preliminary Study of the Effects of Venous Drainage Position on Arterial Blood Supply and Venous Return within the Conjoined Flap

Background:

Conjoined flap viability is associated with arterial blood supply and venous return. This study aimed to assess the effects of venous drainage position on arterial blood supply and venous return within the conjoined flap.

Methods:

Fifty-four rats were divided randomly into three groups (n = 18 per group). In experimental group 2, only the right intercostal posterior artery and the left iliolumbar vein were maintained; meanwhile, only the right intercostal posterior artery and the left intercostal posterior vein were preserved in experimental group 1. The control group had only the right intercostal posterior artery and vein preserved. The distances between angiosomes were measured. At 7 days after surgery, flap survival was evaluated, lead oxide–gelatin flap angiography was performed, and average microvessel density was assessed by hematoxylin and eosin staining, and lactate levels were assessed.

Results:

The distance between angiosomes I and II was the shortest, whereas angiosomes I and III were most distant (p < 0.05). At 7 days after surgery, survival rates in experimental group 2 and experimental group 1 were both 100 percent, whereas 86.5 ± 1.6 percent of controls survived. Furthermore, angiogenesis was more obvious in experimental group 2 than in experimental group 1 and controls. Moreover, lactate levels were lower in experimental group 2 (7.47 ± 0.17 mM) and experimental group 1 (8.03 ± 0.31 mM) compared with control values (9.98 ± 0.37 mM; p < 0.05).

Conclusion:

Changes in position of venous drainage might cause continuous arterial high-pressure perfusion and venous superdrainage, which improves flap survival.

Intraoperative Indocyanine Green Angiography for Fat Necrosis Reduction in the Deep Inferior Epigastric Perforator (DIEP) Flap

BACKGROUND

Fat necrosis is a frequent complication (up to 62.5%) of microsurgical breast reconstruction using the deep inferior epigastric perforator (DIEP) flap. This could have important clinical and psychological repercussions, deteriorating the results and increasing reconstruction costs.

OBJECTIVES

The aim of this study was to demonstrate the intraoperative use of indocyanine green angiography (ICGA) to reduce fat necrosis in DIEP flap.

METHODS

Sixty-one patients who underwent unilateral DIEP flap procedures for breast reconstruction after oncological mastectomy were included (24 cases with intraoperative use of ICGA during surgery, 37 cases in the control group). The follow-up period was 1 year after surgery. The association between the use of ICGA and the incidence of fat necrosis in the first postoperative year, differences in fat necrosis grade (I-V), differences in fat necrosis requiring reoperation, quality of life, and patient satisfaction were analyzed.

RESULTS

The incidence of fat necrosis was reduced from 59.5% (control group) to 29% (ICG-group) (P = 0.021) (relative risk = 0.49 [95% CI, 0.25-0.97]). The major difference was in grade II (27% vs 2.7%, P = 0.038). The number of second surgeries for fat necrosis treatment was also reduced (45.9% vs 20.8%, P = 0.046). The ICG group had higher scores on the BREAST-Q.

CONCLUSIONS

Intraoperative ICGA is a useful technique for reconstructive microsurgery that might improve patient satisfaction and reduce the incidence of fat necrosis by half as well as reduce its grade, especially in small fat necrosis cases; consequently, ICGA could reduce the number of secondary surgeries for treatment of fat necrosis.

LEVEL OF EVIDENCE: 4

The use of laser speckle contrast imaging to predict flap necrosis: An experimental study in a porcine flap model

BACKGROUND

We evaluated the use of laser speckle contrast imaging (LSCI) in the perioperative planning in reconstructive flap surgery. The aim of the study was to investigate whether LSCI can predict regions with a high risk of developing postoperative necrosis. Our hypothesis was that, perioperatively, such regions have perfusion values below a threshold value and show a negative perfusion trend.

METHODS

A porcine flap model based on the cranial gluteal artery perforator was used. Images were acquired before surgery, immediately after surgery (t = 0), after 30 min (t = 30 min), and after 72 h (t = 72 h). Regions of interest (ROIs) were chosen along the central axis of the flap. Clinical evaluation of the flap was made during each time point.

RESULTS

At t = 72 h, a demarcation line could be seen at a distance of 15.8 ± 0.4 cm away from the proximal border of the flaps. At t = 0, perfusion decreased gradually from the proximal to the distal ROI. At t = 30 min, perfusion was significantly lower in the ROI distal to the final demarcation line than that at t = 0, and in all flaps, these ROIs had a perfusion <25 PU. At t = 72 h, perfusion in the ROI proximal to this line returned to baseline levels, whereas perfusion in the distal ROI remained low.

CONCLUSIONS

In our model, a decrease in perfusion during the first 30 min after surgery and a perfusion <25 PU at t = 30 min was a predictor for tissue morbidity 72 h after surgery, which indicates that LSCI is a promising technique for perioperative monitoring in reconstructive flap surgery.

A Systematic Study of Vascular Distribution Characteristics and Axis Design of Various Flap Types

Background

The aim of this study was to define blood flow characteristics of multiple types of flaps and the theoretical basis of flap axis design.

Material/Methods

Sixty Sprague-Dawley (SD) rats were randomly divided into 6 groups: a normal skin group, and 5 groups with different types of flap: abdominal flap group, dorsal flap group, single-perforator flap group, double-perforators flap group, and delayed cutaneous nerve flap group. The vascular distribution characteristics of normal skin and various flap types were observed by gross morphology of specimens and X-ray after perfusion.

Results

There were distinct differences in vascular anastomosis and density in dorsal and ventral SD rats. The area of flap survival in the dorsal flap group was superior to that in the abdominal flap group, but the flap axis of the 2 groups passed straight through the middle of the pedicle. The flap surviving area in the double-perforators flap group was remarkably larger than in the single-perforator flap group, while the flap axis in the single-perforator flap group passed straight through the perforators, and in the double-perforators flap group there was a linking vessel between the 2 perforators. There were linking and reticulate vessels, in addition, linking vessels and cutaneous nerves were concomitant in the delayed cutaneous nerve flap group. The flap axis was the travel route of the cutaneous nerve.

Conclusions

Variations in flap blood supply patterns and axes with alterations based on flap types have implications for flap survival. Understanding blood flow characteristics within each flap type and accurately designing the flap axis is essential for flap survival.

Enhanced Preoperative Deep Inferior Epigastric Artery Perforator Flap Planning with a 3D-Printed Perforasome Template: Technique and Case Report

Optimizing preoperative planning is widely sought in deep inferior epigastric artery perforator (DIEP) flap surgery. One reason for this is that rates of fat necrosis remain relatively high (up to 35%), and that adjusting flap design by an improved understanding of individual perforasomes and perfusion characteristics may be useful in reducing the risk of fat necrosis. Imaging techniques have substantially improved over the past decade, and with recent advances in 3D printing, an improved demonstration of imaged anatomy has become available. We describe a 3D-printed template that can be used preoperatively to mark out a patient's individualized perforasome for flap planning in DIEP flap surgery. We describe this "perforasome template" technique in a case of a 46-year-old woman undergoing immediate unilateral breast reconstruction with a DIEP flap. Routine preoperative computed tomographic angiography was performed, with open-source software (3D Slicer, Autodesk MeshMixer and Cura) and a desktop 3D printer (Ultimaker 3E) used to create a template used to mark intra-flap, subcutaneous branches of deep inferior epigastric artery (DIEA) perforators on the abdomen. An individualized 3D printed template was used to estimate the size and boundaries of a perforasome and perfusion map. The information was used to aid flap design. We describe a new technique of 3D printing a patient-specific perforasome template that can be used preoperatively to infer perforasomes and aid flap design.

Double-Pedicled Free Deep Inferior Epigastric Perforator Flap for the Coverage of Thigh Soft-Tissue Defect

Soft-tissue defects caused by radiation injury are a challenging task for the reconstructive surgeon, due to the extent of the soft-tissue damage and the associated injuries of the local blood vessels and bone tissue. We present the application of the versatile deep inferior epigastric perforator (DIEP) flap for the coverage of an extended lateral thigh soft-tissue defect after the surgical resection of an undifferentiated pleomorphic high-grade sarcoma, neoadjuvant chemotherapy, and adjuvant chemo- and radiotherapy. A double-pedicled free DIEP flap (756 cm²) was harvested and anastomosed to the transverse branch of the lateral femoral circumflex artery and a lateral branch of the popliteal artery (P1). The flap survived completely without serious complications, and the patient was able to walk with crutches 3 months postoperatively. This is the first case report of a free bipedicled DIEP flap for the coverage of a thigh defect in a male patient.