Defining Fat Necrosis in Plastic Surgery:

Inhibition of Adipocyte Necroptosis Alleviates Fat Necrosis and Fibrosis After Grafting in a Murine Model

BACKGROUND

Because of the delicate structure of the adipose tissue, fat necrosis accounts for 43.7% of all complications after autologous fat grafting; however, its regulation remains unclear.

OBJECTIVES

The purpose of this study was to examine the role of necroptosis in fat graft remodeling after grafting.

METHODS

Clinical fat graft necrosis samples were collected, and the expression levels of the necroptosis marker phosphorylated(p)-MLKL were analyzed. Transcriptome analysis was performed on fat grafts before and 1 week after transplantation in C57BL/6 mouse fat grafting models. Additionally, the in vivo effects of RIPK1 inhibitor Nec-1s or RIPK3 inhibitor GSK'872 on the fat grafting complications, including fat necrosis and fibrosis, were investigated.

RESULTS

Necroptosis markers were observed and associated with higher occurrence of fibrosis in clinical fat graft necrosis samples compared to normal fat tissue. Amplification and RNA-Seq were conducted on RNA isolated from fat grafts before and after grafting. MLKL, RIPK1, and RIPK3's expression levels were significantly upregulated in comparison to controls. Higher expression levels of necroptotic RNAs were associated with higher levels of DAMPs, including Cxcl2, HMGB1, S100a8, S100a9, Nlrp3, and IL33, and activated proinflammatory signaling pathways, including the TNF, NF-kappa B, and chemokine signaling pathways. Necroptotic inhibitor Nec-1s and GSK'872 robustly suppressed the p-MLKL expression level and significantly inhibited necroptotic cell death, especially in adipocytes. Moreover, administration of Nec-1s and GSK'872 significantly alleviated fat necrosis and subsequent fibrosis in fat grafts.

CONCLUSIONS

Collectively, our study findings highlight the potential therapeutic applications of necroptosis inhibitors in preventing fat necrosis and fibrosis after grafting.

LEVEL OF EVIDENCE: 4

Are We Speaking the Same Language? A Systematic Review on the Use of Consistent Language in Reporting Fat Necrosis in Autologous Fat Grafting of the Breast

BACKGROUND

Autologous fat grafting is a widely adopted approach to optimize outcomes in breast reconstruction and augmentation. Although fat necrosis is a well-known consequence of autologous fat grafting, it remains inconsistently defined in the literature. In late 2014, the Food and Drug Administration released a draft guidance to restrict future autologous fat grafting-a statement that was permissively modified in late 2017. In the context of evolving guidelines and autologous fat grafting outcome data, the language and descriptions of fat necrosis are inconsistent in the literature.

METHODS

Five databases were queried for studies reporting fat necrosis following autologous fat grafting for breast reconstruction or augmentation from inception to August 11, 2022. Studies were temporally stratified according to released FDA guidelines: pre-2015, 2015-2017, and 2018-2022.

RESULTS

Sixty-one articles met inclusion criteria. Prior to 2015, 6 of 21 studies (28.6%) offered clear definitions of fat necrosis. In contrast, the 2015-2017 period demonstrated an absence of clear fat necrosis definitions (0/13 studies, p = 0.03). Though the 2018-2022 period exhibited a rise in annual publications compared with the pre-2015 period (5.4 vs. 1.9, respectively, p = 0.04), this was not matched by a rise in clear fat necrosis reporting (14.8% studies, p = 0.45). Across all periods, only 16.4% of articles offered clear definitions, which exhibited wide heterogeneity.

CONCLUSION

Despite the increasing popularity of autologous fat grafting, fat necrosis remains inconsistently defined and described, especially in the context of changing FDA guidelines. This limits the reliable interpretation and application of the current literature reporting fat necrosis outcomes.

LEVEL OF EVIDENCE IV

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 .

Free-style technique versus computed tomographic angiography-guided perforator selection in deep inferior epigastric perforator flap harvest: A prospective clinical study

BACKGROUND

Computed tomographic angiography (CTA) is the preferred diagnostic tool in preoperative deep inferior epigastric perforator (DIEP) flap assessment, though some surgeons prefer approaching perforator selection with intraoperative findings alone.

METHODS

This prospective observational study conducted between 2015 and 2020 assessed our intraoperative decision-making "free-style" technique for DIEP flap harvest. Any patient with indication for immediate or delayed breast reconstruction using abdominally based flaps and who received preoperative CTA was enrolled. Only unilateral cases performed by the same surgeon were considered. Allergy to iodine-based contrast media, renal impairment and claustrophobia were other exclusion criteria. Primary endpoint consisted in comparing operative times and complication rates between free-style technique and CTA-guided approach. Secondary endpoints included evaluation of agreement rate between intraoperative findings and CTA, and identification of variables affecting operative time and complication rate. Demographics, surgical information, agreement versus non-agreement and complications were collected.

RESULTS

Starting from 206 patients, 100 were enrolled. Fifty were assigned to Group A, receiving DIEP flap with free-style technique. The other 50 were assigned to Group B, receiving DIEP flap with CTA-guided perforators selection. Study groups' demographics were homogenous. Operative time was statistically lower (p = .036) in free-style group (252.4 ± 44.77 min vs. 265.6 ± 31.67 min). Complication rates were higher in CTA-guided group (10% vs. 2%) though this was not significant (p = .092). Overall agreement rate in dominant perforator selection between intraoperatively and CTA-based assessment was 81%. Multiple regression analysis showed no variable increased complication rate, though CTA-guided approach, BMI > 30 and harvesting more than one perforator were respectively associated with B-coefficient of 17.391 (2.430-32.351, 95% CI) [p = .023], 3.50 (0.640-6.379, 95% CI) [p = .017] and 18.887 (6.232-31.542, 95% CI) [p = .004], predicting increased operative time.

CONCLUSIONS

The free-style technique proved to be a useful tool for guiding DIEP flap harvest with good sensibility in detecting the dominant perforator suggested by CTA without statistically increasing surgery duration and complications.

Research progress of mechanisms of fat necrosis after autologous fat grafting: A review

Currently, autologous fat grafting is the common surgery employed in the department of plastic and cosmetic surgery. Complications after fat grafting (such as fat necrosis, calcification, and fat embolism) are the difficulties and hotspots of the current research. Fat necrosis is one of the most common complications after fat grafting, which directly affects the survival rate and surgical effect. In recent years, researchers in various countries have achieved great results on the mechanism of fat necrosis through further clinical and basic studies. We summarize recent research progress on fat necrosis in order to provide theoretical basis for diminishing it.

The treatment of symptomatic fat necrosis: A review and introduction of a new treatment algorithm

OBJECTIVE

Fat necrosis (FN) is a well-known complication in plastic surgery. Excision of symptomatic FN has been the gold standard, but it often results in contour irregularities that require subsequent treatment. Different alternative surgical and nonsurgical management strategies have been described; however, there are currently no guidelines. This literature review aims to provide an overview of available treatment options and current management standards to support clinical decision making.

METHOD

A literature search in the databases PubMed, Embase (via Ovid), and Web Of Science was carried out to identify eligible articles. The search strategy included combinations of the following terms: "Fat necrosis "AND (treatment OR management OR therapy). Six articles discussing or reporting management strategies of FN in a plastic surgery context were included.

RESULTS

A variety of techniques were used to manage symptomatic FN. Asymptomatic or small lesions can be treated conservatively. Oil cyst and moderately sized areas of symptomatic FN can effectively be treated by aspiration, ultrasound-assisted liposuction, or needle aeration. Calcified and large areas of FN require excision and debridement of necrotic fat tissue CONCLUSION: At present, there is no consensus on the management of symptomatic FN. The authors propose a new classification system to aid the guidance of management of symptomatic FN.

Introducing a new medical method and innovative suture technique to reduce scars in central lip lift medical surgery

"The central lip lift surgery with a new suture technique called; continuous locking suture in three cases is reported in this article. In this novel method, we used a 5.0 chromic suture by applying a 30-degree angle of the entrance to the skin semi-deeply. We start suturing at the middle of the wound,3-4 mm from the edges of the skin. The needle should be way out at the exact point of entrance, and this process is repeated to reach out to the two sides of the wound. More than 90% of patients (in more than 100 cases) were satisfied with the cosmetic results. Moreover, 90% of cases did not demonstrate any scar after three months without laser or reconstructive ointments. We evaluate many patients who undergo central lip lift surgery with this novel technique, and the scar problem was resolved in more than 90 % of cases with no supportive treatment."

Dual-Layer Rotation: A Versatile Therapeutic Mammoplasty Technique

Background

Multifocal or complex breast lesions are a challenge for breast-conserving surgery, particularly surgery in small breasts or those located in the upper inner quadrant. The dual-layer rotation technique exploits the idea of manipulating the skin and glandular tissue in separate layers to fill the resection cavity via vertical mammoplasty if skin excision is not required, except in the central area.

Methods

The authors performed a retrospective review of consecutive breast cancer patients who underwent DLR mammoplasty between 2017 and 2019 at a single institution. Clinical data, reoperations, surgical complications, delays in adjuvant treatments, and the need for late revisional surgery were evaluated. Aesthetic outcomes were evaluated objectively and subjectively from photographs.

Results

The study included 46 breasts of 40 patients. Tumors were located in the UIQ (30%, 14/46) or in multiple quadrants (22%, 10/46). One third (33%, 13/40) of the patients had a small breast cup size (A–B). Negative margins were primarily achieved in 45 of the 46 breasts. Major complications occurred in three patients, who needed reoperation, and adjuvant therapy was delayed for one of these patients. Late refinement surgery was needed for two patients. The objective and subjective aesthetic outcomes were good or excellent regardless of the tumor position.

Conclusion

As a novel oncoplastic approach, DLR mammoplasty offers a one-step procedure to treat selected breast cancer patients with challenging resection defects due to different breast sizes or lesion locations. The technique preserves the breast’s natural appearance.

Treatment Algorithm of Postsurgical Fat Necrosis of the Breast—Revisited

Fat necrosis is a common complication of breast surgery, with the potential to cause both functional and aesthetic repercussions that can affect patient satisfaction. Although several fat necrosis classification systems have been proposed, fat necrosis management varies widely across institutions, requiring revisiting of existing treatment protocols. We evaluated the postoperative outcomes on 335 breasts following either breast reduction or reconstruction with deep inferior epigastric perforator (DIEP) flaps at our institution between 2016 and 2020, with particular attention to the development of fat necrosis and the need for subsequent surgical intervention. Fat necrosis was diagnosed in 36 (10.74%) breasts, of which 16 (44.4%) were surgically removed and 20 (55.5%) were conservatively managed. Time of fat necrosis diagnosis: early (≤one-month after breast surgery) or late (>1 month) was the only variable associated with surgical intervention. Fat necrosis management should be approached on a case-by-case basis. Whenever possible, conservative management with regular clinical and radiological follow-up, and patient reassurance, should be pursued even for large masses, in the absence of concomitant complications.

Oil Cyst Formation after Lower Blepharoplasty with Fat Grafts

BACKGROUND

Fat grafting is increasingly used as an adjuvant surgery to blepharoplasty to refill the volume loss of an aged face and promote cellular regeneration. Complications, such as hematoma, infection, seroma, and palpable mass, may occur. We collected the patients that underwent lower blepharoplasty combined with fat graft to evaluate the incidence of oil cyst formation in the lower eyelid and to identify risk factors.

MATERIAL AND METHODS

A retrospective review was performed of all patients who underwent lower or total blepharoplasty combined with fat graft at the authors' institution between January 2018 and June 2020. Complication rates were observed, and associations between preoperative variables and outcomes were assessed.

RESULTS

A total of 119 patients were included in the series (all bilateral, 238 eyelids). The average patient age was 54.88 ± 11.94 years, and the average grafted fat was 1.88 ± 1.0 mL. On a per-eyelid basis for all patients, the complication rate of oil cyst formation was 6.72% (16 of 238 eyelids). The occurrence of oil cyst formation was associated with hypertension (P = 0.012; adjusted odds ratio, 9.27; 95% confidence interval, 1.62-52.99) and diabetes mellitus (P = 0.005; adjusted odds ratio, 14.02; 95% confidence interval, 2.22-88.45), but not associated with anticoagulants use (P = 0.931), age (P = 0.784), sex (P = 0.317), or fat volume (P = 0.215). The mean interval between the fat graft procedure and oil cyst noted was 236.5 ± 118.9 days.

CONCLUSIONS

Oil cyst in lower eyelid can be defined as a palpable, firm, and persistent subcutaneous cystic lesion found postoperatively in any size during physical examination. The complication rate of oil cyst formation occurring after lower blepharoplasty with autologous fat grafting is 6.72%. Hypertension and diabetes mellitus maybe are risk factors of oil cyst formation. Steroid injection, needle capsulotomy, liposuction, and excision are safe and effective treatments. Reduce surgical trauma by diminishing anterior lamina trauma and capsulopalpebral fascia repair might decrease the complication rate of oil cyst formation.Transconjunctival lower blepharoplasty with fat graft or 2-stage surgery may be a choice to prevent oil cyst formation.

[Diagnosis and management of fat necrosis after autologous fat transplantation of breast]

Objective

To review the diagnosis and management of fat necrosis after autologous fat transplantation of breast.

Methods

Based on the latest related literature, the pathology, clinical and radiographic examinations, influence factors, as well as the management of fat necrosis after autologous fat transplantation for breast augmentation and reconstruction were summarized.

Results

Fat necrosis after breast autologous fat transplantation is histologically manifested as hyaline degeneration, fibrosis, and calcification. The diagnosis of fat necrosis includes clinical examination, imaging examination (ultrasound, mammography, and MRI), and biopsy. The occurrence of fat necrosis is closely related to patient's own reason and fat transplantation technology. Optimizing the process of fat acquisition, purification, and transplantation can reduce the occurrence of fat necrosis. Intervention or not after fat necrosis depends on the nature of the nodules. According to the nature of the the nodules, various methods such as simple aspiration, vibration amplification of sound energy at resonance liposuction, or direct excision can be selected.

Conclusion

Fat necrosis after autologous fat transplantation of breast are difficult to control. How to process fat to minimize the injury and maximize the activity of grafted fat needs further researches.

A Systematic Review of the Utility of Indocyanine Angiography in Autologous Breast Reconstruction

BACKGROUND

In the last decade, a number of studies have demonstrated the utility of indocyanine green (ICG) angiography in predicting mastectomy skin flap necrosis for immediate breast reconstruction. However, data are limited to investigate this technique for autologous breast reconstruction. Although it may have the potential to improve free flap outcomes, there has not been a large multicenter study to date that specifically addresses this application.

METHODS

A thorough literature review based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines was conducted. All studies that examined the use of intraoperative ICG angiography or SPY to assess perfusion of abdominally based free flaps for breast reconstruction from January 1, 2000, to January 1, 2020, were included. Free flap postoperative complications including total flap loss, partial flap loss, and fat necrosis were extracted from selected studies.

RESULTS

Nine relevant articles were identified, which included 355 patients and 824 free flaps. A total of 472 free flaps underwent clinical assessment of perfusion intraoperatively, whereas 352 free flaps were assessed with ICG angiography. Follow-up was from 3 months to 1 year. The use of ICG angiography was associated with a statistically significant decrease in flap fat necrosis in the follow-up period (odds ratio = 0.31, P = 0.02). There was no statistically significant difference for total or partial flap loss.

CONCLUSIONS

From this systematic review, it can be concluded that ICG angiography may be an effective and efficient way to reduce fat necrosis in free flap breast reconstruction and may be a more sensitive predictor of flap perfusion than clinical assessment alone. Future prospective studies are required to further determine whether ICG angiography may be superior to clinical assessment in predicting free flap outcomes.

Orbital fat necrosis following a revision endoscopic dacryocystorhinostomy

INTRODUCTION

This report details a case of a preseptal fat necrosis in a 55-year old female, following a revision endoscopic dacryocystorhinostomy (DCR).

CASE DESCRIPTION

Upon initial examination, significant right eyelid swelling, tenderness, and pain in the peritrochlear area, was observed. An overlying skin edema was noted in the supero-medial portion of the right upper eyelid. This edema was palpable, firm, and tender. Orbital computed tomography revealed heterogeneous infiltration including an ill-defined margin in the preseptal regions of the clinically evident location. Marked, soft tissue edema and thickening in the inner preseptal area were demonstrated through magnetic resonance images (MRI). An excision biopsy was required as the lesion did not respond to medical treatment. A necrosis of adipose tissue surrounded by abundant foamy macrophages and inflammatory infiltrates, was exposed.

CONCLUSION

This is an exceptionally rare case of orbital fat necrosis following a DCR. Four possible mechanisms for the development of fat necrosis are discussed.

Fat necrosis in level I oncoplastic breast-conserving surgery focusing on a modified round block technique

The modified round block technique (MRBT) is a level I oncoplastic breast-conserving surgery (OBCS), which contains a very wide glandular flap created by extensive dual-plane undermining that is achieved by entire subcutaneous dissection and approximately 50% dissection of the breast parenchyma from the pectoralis muscle. A retrospective analysis was performed for 100 patients who underwent OBCS using MRBT from February 2009 to October 2017. The incidence of positive margin was 7.0% (seven cases), and there has been no local recurrence during a median follow-up period of 68 months. Short- and long-term complications included fat necrosis (11.0%), infection (4.0%), and hematoma formation (4.0%). When patients were divided into two groups based upon the preoperative mammography findings, fat necrosis occurred in 5.2% of the patients with extremely dense or heterogeneously dense mammography, and in 19.0% of patients with scattered fibroglandular or entire fat mammography, which showed a statistically significant difference. Therefore, in level I OBCS, the extent of dual-plane undermining should be minimized to less than 50% of the total parenchyma in fatty breasts.

Tissue-Engineered Soft-Tissue Reconstruction Using Noninvasive Mechanical Preconditioning and a Shelf-Ready Allograft Adipose Matrix

BACKGROUND

Adipose tissue defects leading to severe functional (disability) and morphologic (disfigurement) morbidity are often treated in plastic surgery with fat grafting, which can be limited by resorption, necrosis, and cyst formation. This study aimed to assess whether adipose scaffolds could provide an environment for in situ autologous fat grafting, and to study whether adipose cell migration and proliferation (adipogenesis) within scaffolds could be enhanced by preliminarily increasing the vascularity (preconditioning) of the surrounding tissue receiving the scaffolds.

METHODS

Using an established rodent model of subcutaneous tissue/scaffold grafting, the authors tested the potential of a human-derived, shelf-ready, injectable, decellularized allograft adipose matrix to reconstruct soft-tissue defects when used in combination with noninvasive mechanical (suction-induced) skin preconditioning.

RESULTS

Combined use of the allograft adipose matrix and noninvasive skin preconditioning significantly improved long-term volume retention (50 to 80 percent higher at a 12-week follow-up) and histologic quality of reconstructed tissues compared with standard of care (autologous adipose grafts). The components of the allograft adipose matrix supported adipogenesis and angiogenesis. Combining the allograft adipose matrix with living adipose grafts mitigated negative outcomes (lower long-term volume retention, higher presence of cystic-like areas).

CONCLUSIONS

This study suggests that the synergistic use of the allograft adipose matrix and noninvasive tissue preconditioning provides an effective solution for improving fat grafting. These strategies can easily be tested in clinical trials and could establish the basis for a novel therapeutic paradigm in reconstructive surgery.

Evidence-Based Abdominoplasty Review With Body Contouring Algorithm

Abdominal contour deformities are an aesthetic challenge to the plastic surgeon. Patients present with diverse clinical histories, multiple comorbidities, and unique aesthetic demands. Weight loss, previous pregnancy, and aging are 3 principal indications for abdominoplasty. Bariatric surgery has increased demand for body contouring procedures. This heterogeneous patient cohort means a "one-size-fits-all" abdominoplasty is not appropriate. Precise evaluation, evidence-based decision-making, and artistic acumen are required while balancing patient goals with safe, realistic, and long-lasting aesthetic outcomes. This article reviews surgical options for abdominal body contouring, providing an evidence-based treatment algorithm for selecting the appropriate procedure for each patient to maximize clinical and patient reported outcomes.

Myth-Busting the DIEP Flap and an Introduction to the Abdominal Perforator Exchange (APEX) Breast Reconstruction Technique: A Single-Surgeon Retrospective Review

Supplemental Digital Content is available in the text.

This and Related “Classic” Articles Appear on Prsjournal.com for Journal Club Discussions.

Background:

Anatomical variations in perforator arrangement may impair the surgeon’s ability to effectively avoid rectus muscle transection without compromising flap perfusion in the deep inferior epigastric artery perforator (DIEP) flap.

Methods:

A single surgeon’s experience was reviewed with consecutive patients undergoing bilateral abdominal perforator flap breast reconstruction over 6 years, incorporating flap standardization, pedicle disassembly, and algorithmic vascular rerouting when necessary. Unilateral reconstructions were excluded to allow for uniform comparison of operative times and donor-site outcomes. Three hundred sixty-four flaps in 182 patients were analyzed. Operative details and conversion rates from DIEP to abdominal perforator exchange (“APEX”) arms of the algorithm were collected. Patients with standardized DIEP flaps served as the controlling comparison group, and outcomes were compared to those who underwent abdominal perforator exchange conversion.

Results:

The abdominal perforator exchange conversion rate from planned DIEP flap surgery was 41.5 percent. Mean additional operative time to use abdominal perforator exchange pedicle disassembly was 34 minutes per flap. Early postsurgical complications were of low incidence and similar among the groups. One abdominal perforator exchange flap failed, and there were no DIEP flap failures. One abdominal bulge occurred in the DIEP flap group. There were no abdominal hernias in either group. Fat necrosis rates (abdominal perforator exchange flap, 2.4 percent; DIEP flap, 3.4 percent) were significantly lower than that historically reported for both transverse rectus abdominis musculocutaneous and DIEP flaps.

Conclusions:

This study revealed no added risk when using pedicle disassembly to spare muscle/nerve structure during abdominal perforator flap harvest. Abdominal bulge/hernia was nearly completely eliminated. Fat necrosis rates were extremely low, suggesting benefit to pedicle disassembly and vascular routing exchange when required.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Therapeutic, III.

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

Fat Necrosis After Autologous Fat Transfer (AFT) to Breast: Comparison of Low-Speed Centrifugation with Sedimentation

BACKGROUND

Despite the advantages of autologous fat transfer to the breast, there are many complications after the surgery, such as oil cysts, calcification and palpable breast nodules. The fat purification process is a key step to reduce those complications, but there is currently no standard processing method. This study was designed to compare the incidence of fat necrosis after autologous fat grafting to the breast with low-speed centrifugation and sedimentation.

METHODS

This study analyzed 100 patients (167 breasts) who underwent autologous fat grafts to the breasts from January, 2015 to March, 2017. Patients were divided into two groups randomly, low-speed centrifugation (800 r/min) and sedimentation (15 min). Postoperative fat necrosis such as oil cysts and palpable breast nodules was measured using physical examination and breast ultrasound 3 months after the surgery. The number and the diameter of the fat necroses were detected.

RESULTS

A total of 100 patients (167 breasts) were included this research. There were 21 breasts with clinically palpable nodules (12.57%); fifteen (19.48%) were in the low-speed centrifugation group and six (6.67%) were in the sedimentation group (p < 0.05). According to postoperative breast ultrasounds, there were 83 breasts with hypoechoic cyst formations (49.7%); forty-five (58.44%) in the low-speed centrifugation group and 38 (42.22%) in the sedimentation group (p < 0.05). A positive correlation between the number of operative sessions and fat necrosis was found out.

CONCLUSION

Although low-speed centrifugation could achieve higher fat purification efficacy when compared with sedimentation, it causes more fat necrosis than sedimentation, such as clinically palpable nodules and subclinical nodules, especially in patients who had a history of breast surgery and those who needed more than one fat grafting session.

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 .

Preclinical Optimization of a Shelf-Ready, Injectable, Human-Derived, Decellularized Allograft Adipose Matrix

IMPACT STATEMENT

Trauma, disease, surgery, or congentital defects can cause soft tissue losses in patients, leading to disfigurement, functional impairment, and a low quality of life. In the lack of available effective methods to reconstruct these defects, acellular adipose matrices could provide a novel therapeutic solution to such challenge.

Predicting venous congestion before DIEP breast reconstruction by identifying atypical venous connections on preoperative CTA imaging

BACKGROUND

Venous congestion is the principle cause of flap failure after microsurgical breast reconstruction. We aim to correlate preoperative computed tomography angiography (CTA) findings with postoperative venous congestion to predict patients at risk of congestion.

METHODS

All patients undergoing deep inferior epigastric perforator (DIEP) breast reconstruction between August 2009 and August 2013 underwent preoperative CTA and prospectively entered the study. Patients with postoperative venous congestion were matched with a similar cohort of complication-free patients. Preoperative CTAs were randomized and re-interpreted by a radiologist, blinded to the subsequent clinical outcome. Inter-group comparisons were performed.

RESULTS

Two hundred and forty DIEP flaps were performed in 202 patients over the 4-year study. Venous congestion affected 15 flaps (6.3%). Preoperative CTA showed significantly more atypical venous connections between deep and superficial systems in congested flaps compared to controls (66.7% vs. 8%; P < .0001), with a positive predictive value of 83%. Atypical connections were narrow, tortuous, or incomplete. Patients with congestion-free flaps had more normal connections (80% vs. 26.7%; P < .001) and more cranial perforators (P = .02). Similar CTA findings between groups included perforator size and lateral position, superficial inferior epigastric vein size, crossing of midline, and absent connections (P > .05).

CONCLUSIONS

Preoperative CTA identifies atypical venous connections between deep and superficial systems that increase the risk of postoperative DIEP congestion five-fold. Identifying atypical venous connections maximizes the chances of flap survival and minimizes complications for patients considering DIEP breast reconstruction.