Donor-Site Hernia Repair in Abdominal Flap Breast Reconstruction: A Population-Based Cohort Study of 7929 Patients

Abdominal Wall Reinforcement Using OviTex after Deep Inferior Epigastric Perforator Flap

Abdominal wall bulges and hernias are not uncommon complications following deep inferior epigastric perforator (DIEP) flap harvest. Abdominal wall reinforcement using synthetic meshes has been found to decrease bulges by up to 70%; however, such meshes can be associated with other issues such as seromas and infections. Reinforced tissue matrix (RTM) mesh can be used for abdominal wall reinforcement due to its ability to recruit fibroblasts and provide a scaffold for cellular proliferation. There is no literature on the use of OviTex mesh for abdominal wall reinforcement following DIEP flap harvest. Therefore, this study aimed to evaluate the efficacy and safety of its use in this setting.A retrospective review was performed on patients undergoing DIEP flap harvest between January 2020 and June 2023. Patients who had completed at least 12 months of follow-up visits were included. Descriptive, univariate, and multiple logistic regression analyses were completed.A total of 199 patients were included. The mean age at the time of surgery was 51.1 ± 10.0 years and the mean body mass index (BMI) was 30.2 ± 5.9 kg/m2. Abdominal wall reinforcement was completed in 85 (42.7%) patients. Patients who had OviTex placed developed fewer bulges compared to the non-mesh cohort (0% vs. 5.3%, p = 0.04). Furthermore, OviTex mesh did not increase adverse events and was not significantly different in seroma/hematoma rates when compared to the non-mesh cohort (10.6% vs. 5.3%, p = 0.26).This study demonstrates that OviTex mesh is safe and efficacious in reducing the rate of bulges following DIEP flap harvest without increasing other complications.

A DIEP Dive into Patient Risk Factors for Hernia and Bulge Development: A Meta-regression

BACKGROUND

 This meta-regression aims to investigate risk factors for abdominal hernia and bulge in patients undergoing deep inferior epigastric perforator (DIEP) flaps and the effect of prophylactic mesh placement on postoperative complications.

METHODS

 A systematic search was conducted in July of 2022 in alignment with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Seventy-four studies published between 2000 and 2022 met the inclusion criteria. Sixty-four studies were included in the analysis for bulge and 71 studies were included in the analysis for hernia. Meta-regressions were run on the proportion of patients experiencing hernia or bulge to assess for patient risk factors and the role of prophylactic mesh placement. Proportions were transformed using the Freeman-Tukey double arcsine method.

RESULTS

 The average rates of hernia and bulge after DIEP flaps were found to be 0.18% and 1.26%, respectively. Increased age (β = 0.0059, p = 0.0117), prior abdominal surgery (β = 0.0008, p = 0.046), and pregnancy history (β = -0.0015, p = 0.0001) were significantly associated with hernia. Active smoking (β = 0.0032, p = 0.0262) and pregnancy history (β = 0.0019, p < 0.0001) were significantly associated with bulge. Neither the perforator vessel laterality nor the number of perforator vessels harvested had any association with hernia or bulge. Prophylactic mesh placement was not associated with hernia or bulge.

CONCLUSION

 Understanding the comorbidities associated with hernia or bulge following DIEP flap breast reconstruction, such as advanced age, prior abdominal surgery, pregnancy history, and active smoking status, allows surgeons to proactively identify and educate high-risk patients. Future studies may further explore whether prophylactic mesh placement offers patients any benefit.

Not All Deep Inferior Epigastric Artery Perforator Flaps Are Created Equal: A Review of Donor-site Morbidity in Abdominally Based Autologous Breast Reconstruction

Background

Breast reconstruction after mastectomy is one of the most common procedures performed in plastic surgery. Autologous reconstruction is associated with better long-term patient satisfaction than implant-based reconstruction but with the requisite donor site and potential for associated morbidity.

Methods

The authors review the literature regarding the technical evolution of abdominally based autologous breast reconstruction and the effect of these changes as well as patient morbidities on bulge, hernia, and all-cause donor-site morbidity.

Results

The impact of patient risk factors on surgical outcomes is evaluated in the context of constantly improving technical surgical innovation. Patients' premorbid abdominal condition and prior abdominal procedures along with traditional complicating factors such as age, obesity, and smoking are associated with increased rates of donor-site complications. Conversely, shorter fascial incisions with or without robotic and laparoscopic assistance are associated with lower rates of abdominal weakness and healing complications than traditional abdominal free flap harvest. Perforator selection and abdominal closure techniques also play a key role.

Conclusions

There are contributions of both patient factors and technical aspects that when optimized can help minimize the risk of donor-site morbidity in deep inferior epigastric artery perforator flap breast reconstruction.

[Robotic-Assisted DIEP Flap Harvest for Autologous Breast Reconstruction: Case Report, Technical Aspects and Identification of Suitable Patients]

BACKGROUND

Robotic-assisted harvest of the deep inferior epigastric perforator (DIEP) flap is an innovative modification of the traditional open preparation for autologous breast reconstruction. It is assumed that donor-site morbidity (herniae, bulging) is reduced by minimising the fascial incision length in robotic-assisted DIEP flap harvest.

MATERIAL & METHODS

This is the first report of a robotic-assisted DIEP harvest in Germany, which was performed in April 2023 at the University Hospital of Freiburg in an interdisciplinary approach of the Departments of Plastic Surgery, Urology and Gynaecology. To determine the value of this novel technique, we assessed the demand by retrospectively performing an analysis of potential patients and conducted a cost analysis based on the breast reconstructions with DIEP flap harvest performed between April 2021 and May 2023 at the Department of Plastic Surgery at Freiburg University Hospital. To this end, we carried out a retrospective analysis of preoperative CT angiographies to determine the proportion of patients suitable for a robotic-assisted procedure in a post-hoc analysis. Furthermore, we describe the basic robotic-assisted techniques and discuss the TEP and TAPP laparoscopic approaches.

RESULTS

In line with the previously published literature, a short intramuscular course (≤25 mm) and a perforator diameter of≥1.5 mm and≥2.7 mm (subgroup) were defined as a crucial condition for the robotic-assisted procedure. We analysed 65 DIEP flaps harvested in 51 patients, of which 26 DIEP flaps in 22 patients met both criteria, i. e.≤25 mm intramuscular course and≥1.5 mm diameter of the perforator, while 10 DIEP flaps in 10 patients additionally met the criteria of the subgroup (≥2.7 mm diameter). Based on the intramuscular course of the perforators in the CT angiographies of those 26 DIEP flaps, a potential reduction of the fascial incision of 96.8±25.21 mm (mean±standard deviation) compared with the conventional surgical approach was calculated. The additional material costs in our case were EUR 986.01. However, ischaemia time was 33,5 minutes longer than the median of the comparative cohort.

CONCLUSION

The robotic-assisted procedure has already proven to be a feasible alternative in a suitable patient population. However, further studies are needed to confirm that robotic-assisted DIEP flap harvest actually reduces harvest site morbidity and thereby justifies the additional costs and complexity.

Outcomes of posterior component separation with transversus abdominis release for repair of abdominally based breast reconstruction donor site hernias

PURPOSE

Abdominally based autologous breast reconstruction (ABABR) is common after mastectomy, but carries a risk of complex abdominal wall hernias. We report experience with posterior component separation (PCS) and transversus abdominis release (TAR) with permanent synthetic mesh repair of ABABR-related hernias.

METHODS

Patients at Cleveland Clinic Foundation and Penn State Health were identified retrospectively. Outcomes included postoperative complications, hernia recurrence, and patient-reported outcomes (PROs): Hernia Recurrence Inventory, HerQLes Summary Score, Patient-Reported Outcome Measurement Information System (PROMIS) Pain Intensity 3a Survey, and the Decision Regret Scale (DRS).

RESULTS

Forty patients underwent PCS/TAR repair of hernias resulting from pedicled (35%), free (5%), muscle-sparing TRAMs (15%), and DIEPs (28%) from August 2014 to March 2021. Following PCS, 30-day complications included superficial surgical site infection (13%), seroma (8%), and superficial wound breakdown (5%). Five patients (20%) developed clinical hernia recurrence. At a minimum of 1 year, 17 (63%) reported a bulge, 12 (44%) reported pain, median HerQLes Quality Of Life Scores improved from 33 to 63/100 (p value < 0.01), PROMIS 3a Pain Intensity Scores improved from 52 to 38 (p value < 0.05), and DRS scores were consistent with low regret (20/100).

CONCLUSION

ABABR-related hernias are complex and technically challenging due to missing abdominal wall components and denervation injury. After repair with PCS/TAR, patients had high rates of recurrence and bulge, but reported improved quality of life and pain and low regret. Surgeons should set realistic expectations regarding postoperative bulge and risk of hernia recurrence.

To Ablate or Not to Ablate: Does Umbilectomy Decrease Donor-Site Complications in DIEP Flap Breast Reconstruction?

BACKGROUND

Improving outcomes for deep inferior epigastric perforator (DIEP) flap breast reconstruction is an evolving area of interest. The aim of this study was to evaluate the effect of umbilectomy in abdominally based breast reconstruction.

METHODS

This retrospective study evaluated postoperative outcomes of patients who underwent autologous DIEP flap breast reconstruction at an academic center between January of 2015 and December of 2021 performed by one of two reconstructive surgeons. The primary outcome variable was abdominal donor-site complications. A secondary outcome variable was treatment outcomes for complications. Covariates included demographic information, comorbidities, cancer treatment, and smoking.

RESULTS

A total of 408 patients underwent DIEP flap breast reconstruction, with 194 (47.5%) undergoing umbilectomy. Umbilectomy resulted in decreased number of total wounds per patient (0.35 ± 0.795) compared with umbilical preservation (0.75 ± 1.322; P < 0.001), as well as decreased associated risk of any reported wounds (OR, 0.530; P = 0.009). Associations that trended toward significance occurred between umbilectomy and minor wound separation and partial necrosis, with both showing decreased risk. A significant association was noted between umbilectomy and donor-site seroma [χ 2 (1) = 6.348; P = 0.016], showing an increased risk (OR, 5.761).

CONCLUSIONS

Umbilectomy should be discussed with patients and considered as a part of DIEP flap breast reconstruction given the reduction in the risk of abdominal donor-site wounds. Although umbilectomy decreases the rate of wounds, it can increase the risk of seroma; therefore, other interventions, such as progressive tension sutures, may be explored to aid in reducing seroma and improving wound healing.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Correlation between abdominal visceral volume measured by a simple procedure and bulging at the abdominal free flap donor site for breast reconstruction

BACKGROUND

Breast reconstructions using autologous abdominal tissue result in breasts with a natural shape and consistency. One of the major complications is abdominal bulging. Because of the increased abdominal wall tension, high visceral volume (not visceral fat alone) may increase the occurrence rate of abdominal bulging. A simple procedure involving CT imaging was used to assess this relationship in patients undergoing an abdominal free flap for unilateral breast reconstruction.

METHODS

A total of 278 patients were enrolled in this study. The patients' demographics, the thicknesses of visceral volume were compared (Bulging (+) vs. Bulging (-)). Visceral volume was investigated based on the horizontal thickness, which was measured at the thickest part at the level of the umbilical fossa between both sides under the transverse abdominis muscles.

RESULTS

Bulging (+) consisted of 39 patients (14.0%), whereas Bulging (-) included 239 patients. Patients with Bulging (+) were significantly older, had higher gestational history rate, and had thin rectus abdominis muscle. In terms of visceral volume, the Bulging (+) group had significantly higher horizontal thicknesses (median 233 mm vs. 219 mm, P < 0.001). No significant differences were observed with respect to other factors (age, BMI, history of laparotomy, and operative details). The multivariate logistic regression analysis revealed that the thickness of the rectus abdominis muscle, horizontal visceral volume, and gestational history were independently significant predictors.

CONCLUSIONS

Not only the patients with thin rectus abdominis muscle but also patients with a thick horizontal visceral volume may have a higher risk of abdominal bulging.

Robotic Harvest of the Deep Inferior Epigastric Perforator Flap for Breast Reconstruction: A Case Series

BACKGROUND

Robotic surgery is emerging as a viable tool in reconstructive surgery. Harvesting of the deep inferior epigastric perforator flap is typically performed through an anterior approach, which involves a long fascial incision. A robotic approach allows the deep inferior epigastric pedicle to be harvested from the posterior surface. This approach reduces the length of the fascial incision and should decrease the abdominal morbidity associated with large fascial dissections.

METHODS

A case series study of 21 patients who underwent a robotic deep inferior epigastric perforator or during a 12-month period for breast reconstruction was performed. Patient demographics, surgical characteristics, and complications were assessed.

RESULTS

Mean patient age was 54.6 ± 7.6 years, and mean body mass index was 30.4 ± 3.9 kg/m2. Mean fascial incision and pedicle length were 3.6 ± 1.6 cm and 13.3 ± 1 cm, respectively. None of the patients required conversion to open harvest. Mean length of hospital stay was 3.8 ± 0.9 days. Surgical site occurrences were identified in five patients (31.3 percent). One patient had delayed wound healing at the donor site. None of the patients developed hernia or bulge. The mean benefit (B = C - A), defined as length of fascial incision spared and measured as the difference between pedicle length and intramuscular course, was 9.83 ± 2.28 cm. The precision of computed tomography angiography in identifying the intraoperative fascial incision was 86 percent.

CONCLUSION

The robotic deep inferior epigastric perforator flap is a safe and reliable technique that decreases the length of fascial incision and short-term complications associated with the open approach.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Prevention of Abdominal Bulging Using Onlay Dermal Autografts from Discarded Zone IV TRAM Flap Tissue

While the transverse rectus abdominis myocutaneous (TRAM) flap is a popular option for abdominal-based breast reconstruction, abdominal wall morbidities such as bulging or hernia remain a concern. Here, we introduced a surgical technique for reinforcing the abdominal wall using an onlay autograft obtained from discarded zone IV tissue following a primary closure. We compared abdominal wall morbidities between patients receiving an onlay graft and those receiving primary closure only. We retrospectively reviewed the medical charts of patients who underwent breast reconstruction using a TRAM flap between December 2018 and May 2021. Additionally, we assessed donor-site morbidities based on physical examination. Of the 79 patients included, 38 had received a dermal graft and 41 had not. Donor-site morbidities occurred in 10 (24.5%) and 1 (2.6%) patients, and bulging occurred in 8 (19.5%) and 1 (2.6%) patients in the primary closure and dermal autograft groups, respectively. A statistically significant difference in the incidence of bulging was observed between the groups (p = 0.030). In conclusion, the introduction of a dermal autograft after primary closure can successfully ameliorate morbidities at the TRAM flap site.

Autologous Reconstruction after Mastectomy for Breast Cancer

Background

Women undergoing autologous reconstruction (AR) after mastectomy for breast cancer and their surgeons must make decisions regarding timing of the AR and choose among various flap types. We conducted a systematic review to evaluate the comparative benefits and harms of (1) timing of AR relative to chemotherapy and radiation therapy, and (2) various flap types for AR.

Methods

We searched Medline, Embase, Cochrane CENTRAL, CINAHL, and ClinicalTrials.gov for studies, from inception to March 23, 2021, without language restriction. We assessed risk of bias of individual studies and strength of evidence (SoE) of our findings using standard methods.

Results

We screened 15,936 citations. Twelve mostly high risk of bias studies, including three randomized controlled trials and nine nonrandomized comparative studies met criteria (total N = 31,833 patients). No studies addressed timing of AR relative to chemotherapy or radiation therapy. Six flap types were compared, but conclusions were feasible for only the comparison between transverse rectus abdominus myocutaneous (TRAM) and deep inferior epigastric perforator (DIEP) flaps. The choice of either flap may result in comparable patient satisfaction with breasts and comparable risk of necrosis (low SoE for both outcomes), but TRAM flaps probably pose a greater risk of harm to the area of flap harvest (abdominal bulge/hernia and need for surgical repair) (moderate SoE).

Conclusions

Evidence regarding details for AR is mostly of low SoE. New high-quality research among diverse populations of women is needed for the issue of timing of AR and for comparisons among flap types.

Relationship between Preoperative Abdominal Wall Strength and Bulging at the Abdominal Free Flap Donor Site for Breast Reconstruction

BACKGROUND

Abdominal bulging at the donor site of free abdominal flaps for breast reconstruction is a common postoperative complication. In addition to the thickness of abdominal muscles, the authors identified the rectus abdominis diastasis as an important factor that compromises abdominal wall strength. This study aimed to assess the relationship between preoperative abdominal wall strength and postoperative abdominal bulging.

METHODS

A total of 224 patients were enrolled in this study. Patient demographics, the rectus and lateral abdominis muscle thicknesses, and the rate of rectus abdominis diastasis were compared (with versus without bulging). Muscle thickness and rectus abdominis diastasis were investigated by preoperative computed tomography.

RESULTS

The group with bulging consisted of 32 patients (14.3 percent), whereas the group without bulging consisted of 192 patients. The group with bulging had a significantly higher gestational history rate. The thickness of the rectus abdominis muscle in the group with bulging was significantly thinner (median, 8.6 mm versus 10.5 mm; p < 0.001) and the rate of rectus abdominis diastasis was significantly higher (78.1 percent versus 32.3 percent; p < 0.001). There were no significant differences with respect to the thickness of the lateral abdominal muscle and the other factors (i.e., age, body mass index, history of laparotomy. and operative details).

CONCLUSIONS

Because the diagnosis of abdominal bulging was based on severity, the rate may be high compared to that reported from previous studies. Because the factor of gestational history correlated to thickness of the rectus abdominis muscle and rectus abdominis diastasis, this factor influenced the occurrence of abdominal bulging. Patients with a thin rectus abdominis muscle and rectus abdominis diastasis were at higher risk of abdominal bulging.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Limiting the fascia incision length in a DIEP flap: Repercussion on abdominal wall morbidity

BACKGROUND

The evolution from free muscle-sparing transverse rectus abdominis myocutaneous flap to deep inferior epigastric perforator (DIEP) flap leads to less donor-site morbidity. However, rectus fascia is usually incised longitudinally from perforator(s) to iliac vessels, often exceeding 15 cm when including longitudinal muscle spreading. By using a limited fascia incisional (LFI-) technique, we try to diminish abdominal wall functional decrease.

METHODS

Twenty-seven patients who underwent unilateral breast reconstructions using free DIEP-flap with limited fascia incision between December 2014 and October 2017 were included in the study. Each patient received a periumbilical electromyogram (EMG) preoperatively, at 6 and 14 weeks postoperatively. They were compared with 27 patients having unilateral breast reconstructions using classic free DIEP-flap, performed at the same department between November 2009 and May 2011.

RESULTS

In our LFI-technique, one vertical (4 cm) incision is made where the pedicle exits the muscle. A second, oblique (3 cm) incision is made more distally where the pedicle runs into the iliac vessels. After release, the pedicle is tunneled through the incisions, leaving all fascia, and therefore muscle, intact. In the LFI-group small neurogenic changes were noticed in only 26% and 11% of the patients at, respectively, 6 and 14 weeks postoperatively. By contrast, in the control group, postoperative neurogenic deviations remained in 37% of the patients at 14 weeks postoperatively; significant different compared to the LFI-group.

CONCLUSION

This study shows the importance of preserving anterior rectus fascia. Nerve supply and abdominal rectus muscle function are less endangered using small segmental fascia incisions. We believe that our technique diminishes donor-site morbidity significantly and improves the postoperative recovery.

Incisional Hernia Incidence, Repair Techniques, and Outcomes Based on 1600 Consecutive Patients Receiving Abdominally Based Autologous Breast Reconstruction

BACKGROUND

As the number of postmastectomy patients who receive abdominally based autologous breast reconstruction (ABABR) increases, the frequency of unique paramedian incisional hernias (IHs) at the donor site is increasing as well. We assessed incidence, repair techniques, and outcomes to determine the optimal treatment for this morbid condition.

METHODS

A total of 1600 consecutive patients who underwent ABABR at the University of Pennsylvania between January 1, 2009, and August 31, 2016, were retrospectively identified. Preoperative and operative information was collected for these patients. Incisional hernia incidence was determined by flap type and donor site closure technique. Repair techniques and postoperative outcomes for all patients receiving IH repair (IHR) after ABABR at our institution were also determined. Univariate and multivariate analyses were conducted.

RESULTS

The incidence of IH after ABABR in our health system was 3.6% (n = 61). Fifteen additional patients were referred from outside hospitals for a total of 76 patients who received IHR. At the time of IHR, mesh was used in 79% (n = 60) of cases (13 biologic and 47 synthetic), with synthetics having significantly lower recurrent IH incidence (10.6% vs 38.5%, P = 0.017) when compared with biologics. Mesh position did not have any statistically significant effect on outcomes; however, sublay mesh position had zero adverse outcomes.

CONCLUSIONS

Mesh should be used in all cases when possible. Although retrorectus repair with mesh is optimal, this plane is often nonexistent or too scarred in after ABABR. Thus, intraperitoneal underlay mesh with primary fascial closure or primary closure with onlay mesh placement should then be considered.

Comparing Outcomes of Flap-Based Salvage Reconstructions in the Radiated Breast

INTRODUCTION

Chest wall irradiation significantly decreases the strength and quality of breast tissue supporting prostheses, increasing the risk of skin breakdown and implant or tissue expander extrusion. Autologous tissue, including the latissimus dorsi (LD) or abdominal-based flaps, including the muscle-sparing transverse rectus abdominis myocutaneous or deep inferior epigastric perforator flaps, may be used to salvage reconstructions. However, data comparing outcomes of the two flap options remains limited. We compare postoperative outcomes from both flap types after autologous salvage reconstruction in irradiated breasts.

METHODS

Charts were retrospectively reviewed from patients who underwent either chest wall radiation or postmastectomy radiation therapy followed by salvage autologous reconstruction with either a LD and an implant or an abdominal-based flap (muscle-sparing transverse rectus abdominis myocutaneous or deep inferior epigastric perforator flaps). Patients with a history of tissue expander or implant failure requiring autologous salvage as part of 2-staged or delayed-immediate breast reconstruction that were operated on between January 2005 and November 2015 were included. Basic demographics, comorbidities, and recipient site complications (infection, wound dehiscence, seroma, hematoma, fat necrosis, and flap failure) were collected.

RESULTS

A total of 72 patients met the inclusion criteria which included 72 flaps; 35 LD and 37 abdominally based flaps. Demographics and comorbidities did not vary significantly between patient groups. Mean follow-up was 767.6 weeks, and all reconstructions were unilateral. Nineteen (26.4%) patients had at least one complication, most commonly minor infections (9.7%). Overall complication rates were not significantly different between flap groups (P = 0.083). Wound dehiscence was significantly higher in the abdominal group (P = 0.045), and fat necrosis also trended higher in this group (P = 0.085). Major infection trended higher in the latissimus group (P = 0.069).

CONCLUSIONS

When comparing outcomes of salvage flap-based reconstruction in radiated breast tissue, overall complication rates were similar when comparing postoperative outcomes between the LD- and abdominal-based flaps. Wound dehiscence was significantly higher when salvage reconstruction used an abdominal flap. Understanding the complications after salvage procedures can help inform decision making and optimize patient care to improve outcomes after breast reconstruction in the radiated breast.

Open Laparoscopic-assisted Repair of Abdominal Wall Hernia and Bulge

Rectus abdominalis musculocutaneous (RAM) flaps have numerous uses in the treatment of large defects. However, flap harvesting can result in abdominal wall incisional hernia and bulge, which are challenging problems. Most of these problems occur below the arcuate line abdominal wall. However, there will be differences that are unique to each patient in the area of hernia or bulge. The open approach repair appears to be used most often, but the precise area of hernia and bulge is often not distinguished. This report describes a case that was treated using a new repair method, which had the clear advantage of allowing the precise area of abdominal wall weakness to be recognized. A 53-year-old man underwent left vertical RAM flap for reconstruction after tongue carcinoma resection. Six months after the operation, lower abdominal wall hernia and bulge were observed. Open laparoscopic-assisted repair was performed. Pneumoperitoneum led to distension of the abdominal cavity and outward stretching of the abdominal wall, so that the area of hernia and bulge protruded to a great degree. In this phase, by making the operating room slightly dark, the area became more clearly recognizable. When direct plication of the hernia and bulging area was required, the contralateral component separation technique was performed. This study describes an inventive repair procedure for abdominal wall hernia or bulge after RAM flap, with the combined advantages of open and laparoscopic repair.

Assessment of the risk of bulge/hernia formation after abdomen-based microsurgical breast reconstruction with the aid of preoperative computed tomographic angiography-derived morphometric measurements

BACKGROUND

No preoperative risk assessment tool is available to predict postoperative bulge formation after abdomen-based breast reconstruction. The authors evaluated the association between clinical variables and morphometric measurements on preoperative computed tomographic (CT) angiography and postoperative abdominal wall morbidity.

METHODS

The authors evaluated all cases of postoperative bulge/hernia and normal controls in patients who underwent preoperative CT angiography and abdomen-based microsurgical breast reconstruction between July 2009 and January 2018. CT-based abdominal wall profiles, including abdominal wall protrusion, abdominopelvic cavity cross-sectional area (CSA), and abdominopelvic cavity-to-total body CSA ratio, were obtained and analyzed. A novel risk stratification scoring system to stratify the risk of bulge/hernia was developed.

RESULTS

Among 463 patients who underwent abdomen-based breast reconstruction, 23 were diagnosed as having a bulge/hernia. Age (OR 2.912; 95% CI 1.157-7.333), lateral row perforator (OR 5.065; 95% CI 1.834-13.986), and abdominal wall protrusion (OR 3.687; 95% CI 1.494-9.100) were significant risk factors associated with postoperative bulge/hernia in the multivariate analysis. Using the risk stratification scoring system, the incidence rates of postoperative bulge/hernia were 1.7%, 4.8%, and 19.0% for low-, intermediate-, and high-risk patients, respectively (p<0.001).

CONCLUSIONS

Age, lateral row perforator, and abdominal wall protrusion were significantly associated with postoperative bulge/hernia formation after abdomen-based microsurgical breast reconstruction. The authors' risk score based on the three variables may help predict and minimize donor-site morbidity.

Spontaneously generated large adipose flaps in vivo tissue engineering chambers

AIM

Previous experiments using our in vivo tissue engineering chamber (TEC) model demonstrated that adipose flap was spontaneously generated without the need for adipocyte or stem cell implantation. The purposes of the present study are to clarify 1) the reproducibility of this method to create adipose flaps, 2) the time-course of adipogenesis, and 3) the long-term stability of the adipose flap generated.

METHODS

The chambers that afforded a protected space for tissue growth were implanted into the groins of rabbits. A vascular pedicle as the vascular source of newly formed tissue, a collagen sponge as a scaffold, and platelet-rich plasma (PRP) and fibroblast growth factor (bFGF) as growth factors were contained within the chamber. There were three experimental groups according to the implantation period of the chamber; Group 4 w, Group 8 w, and Group 12 w (n = 5 in each group).

RESULTS

The percent volumes of the combined adipose/pedicle tissue compared with the total volume of the generated tissue were 14.8% (0.437 cm³/2.96 cm³), 47% (0.87 cm³/1.85 cm³) and 80% (1.82 cm³/2.27 cm³) in Groups 4 w, 8 w, and 12 w, respectively. When a 12-week adipose flap was transferred outside the chamber on its vascular pedicle and retained for a further five months, it became more like mature adipose tissue and had increased fat density.

CONCLUSION

Adipose flaps were spontaneously generated in vivo in TECs at 12 weeks with reproducibility and showed long-term stability outside the chamber following pedicle transfer. The tissue-engineered adipose flap will contribute to breast reconstruction and augmentation without donor-site morbidity.

Umbilical Ablation During Deep Inferior Epigastric Perforator Flap Harvest Decreases Donor Site Complications

BACKGROUND

Donor site complications are a significant source of morbidity for patients undergoing abdominal-based free flap breast reconstruction, but there is a paucity of data regarding minimizing these postoperative complications. We hypothesize that selective ablation of the umbilicus at the time of deep inferior epigastric perforator (DIEP) harvest decreases the incidence of umbilical and abdominal wall complications in high-risk patients.

METHODS

A retrospective review was performed of all patients (n = 117) who underwent DIEP harvest with concomitant umbilical ablation from 2010 to 2015. This cohort was paired with 117 patients who underwent DIEP harvest without umbilical ablation. Preoperative risk factors, intraoperative factors, and postoperative complications were compared.

RESULTS

The umbilical ablation group had significantly higher body mass index (30.9 vs 27.4 kg/m, P < 0.001), presence of umbilical scar (20.9% vs 5.3%, P < 0.001), umbilical hernia (82.9% vs 8.5% P < 0.001), ventral hernia (23.9% vs 1.7%, P < 0.001), and rectus diastasis (10.3% vs 2.6%, P = 0.016). There were no significant differences of smoking, diabetes mellitus, hypertension, prior abdominal surgery, or midline abdominal scar. The umbilical ablation group had a significantly lower rate of postoperative abdominal wound dehiscence and skin loss (11.1% vs 22.2%, P = 0.023) and overall donor site complications (24.8% vs 39.3%, P = 0.017). There was no significant difference in incidence of cellulitis, seroma, or abscess. Mean follow-up time was 1.8 years.

CONCLUSIONS

Selective umbilical ablation in high-risk patients at the time of abdominal flap harvest can result in significantly fewer donor site wound complications, even in the setting of increased risk factors for poor wound healing. This is likely due to avoidance of umbilical incisions and decreased upper abdominal skin undermining. We conclude that umbilical ablation is a viable option to minimize donor site complications, especially in high-risk patients.

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 Phasix, polypropylene, and primary closure of the abdominal donor site after bilateral free flap breast reconstruction: Long-term evaluation of abdominal hernia and bulge formation

BACKGROUND

Abdominal free flap harvest for breast reconstruction may result in significant morbidity in terms of hernias and bulges. Reinforcement of the donor site with mesh has been recommended to minimize the risk of hernias and bulges, but no studies exist evaluating the optimal type of mesh. Polypropylene has traditionally been used but the development of Phasix restorable mesh may be a reasonable alternative. Here, we compared the use of Phasix to polypropylene and primary closure and hypothesize that the former has lower rates of abdominal morbidity in the long term.

PATIENTS AND METHODS

A retrospective review of all patients undergoing bilateral free flap breast reconstruction from the abdomen was performed while patients with pedicle flaps or alternative donor sites were excluded. Patient demographics, medical/surgical history, cancer treatments, and flap type were analyzed. All patients were monitored for a minimum of 2 years for early donor site complications as well as hernia/bulges.

RESULTS

Sixty-six consecutive patients were included (40 patients with Phasix, 20 patients with polypropylene, and 6 patients with primary closure). Use of Phasix mesh resulted in higher initial operative costs ($2,750 vs. $72 vs. $0). Two patients with polypropylene mesh and one patient undergoing primary closure developed an abdominal bulge in an average follow-up of 25.2 months (11.5% vs. 0%, p = .04).

CONCLUSIONS

Mesh placement for abdominal wall reinforcement after bilateral free flap breast reconstruction minimizes the risk of hernias and bulges. Although Phasix results in increased initial costs, abdominal morbidity is significantly decreased after follow-up beyond 2 years.

A systematic review of donor site aesthetic and complications after deep inferior epigastric perforator flap breast reconstruction

Background

The deep inferior epigastric perforator flap (DIEP) has gained widespread popularity in autologous breast reconstruction due to its natural aesthetic results and muscle-sparing design. However, donor site results regarding aesthetic outcome are often less favorable. Despite several studies on surgical technique and improvements of flap harvest, only a small number of studies addressing donor site aesthetic exist.

Methods

A systematic review was performed on donor site aesthetic after DIEP flap harvest according to the PRISMA guidelines. Secondary interests were abdominal wall morbidity and complication rates in general. The following electronic databases were included to identify relevant studies: Medline, Embase, PubMed, Cochrane, and Web of Science.

Results

The search yielded 95 articles for full-text analysis, with only four key studies found on donor site aesthetic specifically. Regarding complication rates, the overall rate of abdominal hernia ranges from 0 to 7.1%. Abdominal bulging occurs in 2.3% to 33%. Besides abdominal wall integrity, wound dehiscence (12-39%), seroma (1-48%), hematoma (1-15%), infections (1-12%), fat necrosis (0-11%) and umbilical necrosis (2-3%) significantly impair donor site aesthetic.

Conclusions

This systematic review reveals that the topic of donor site aesthetic and potential improvement of results has largely been neglected in the past decade. This study provides a thorough evaluation of potential problems that plastic surgeons may encounter and includes recommendations to improve results.

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.

Free tissue transfer with the free rectus abdominis flap in high-risk patients above 65 years: A retrospective cohort study

BACKGROUND

Though technically feasible, free tissue transfer carries the risk of perioperative morbidity and mortality in elderly patients. To minimize the operative treatment time and complication rates, we choose the rectus abdominis muscle (RAM) flap.

METHODS

Between 2012 and 2017, 34 patients (mean age: 74±7 years, range: 65-89 years) with comorbidities underwent defect reconstruction with a free RAM flap. Recipient-sites were: lower extremity (65%), trunk (18%), upper extremity (12%), and head and neck (6%).

RESULTS

The ASA status was 2 in 11 patients, 3 in 21 patients, and 4 in 2 patients. Twenty patients (59%) received additional vascular surgery. Three patients (9%) underwent simultaneous restoration of fractures. The mean operative time (OT) was 325±75 min. There was no total flap loss. Partial flap loss occurred in one patient (3%). The incidence of surgical and medical complications was 32% and 38%: 11 patients experienced a total of 22 surgical complications, of which 15 were major (requiring additional surgery) and 7 minor (conservative treatment). One patient died postoperatively because of progressive respiratory failure. Prolonged OT was highly associated with hematoma formation requiring re-operation (p = 0.01). ASA status was a significant predictor for postoperative critical care monitoring (p = 0.03). Reconstruction was successful in 31 out of 34 patients (91%) during a mean follow-up time of 17.7 ± 8.8 months (range: 2-51 months).

CONCLUSION

The free RAM flap has proven as a reliable and efficient tool in the armamentarium of reconstructive microvascular surgeons with some advantages in the treatment of multimorbid patients older than 65 years.

Preoperative and Postoperative Assessment of Rectus Abdominis Muscle Size and Function following DIEP Flap Surgery

BACKGROUND

Prospective evaluation of rectus abdominis muscle function after deep inferior epigastric artery perforator (DIEP) flap breast reconstruction is limited. Elimination of muscle harvest with this procedure is theoretically associated with preservation of rectus abdominis function and minimization of abdominal wall morbidity. In this study, the authors evaluate the change in rectus abdominis muscle size and function after DIEP flap surgery.

METHODS

Patients undergoing unilateral DIEP flap surgery were recruited prospectively. Using computed tomography, the change in preoperative to postoperative rectus abdominis muscle size was compared between the operative side rectus abdominis muscle and the contralateral, nonoperative control rectus abdominis. Postoperative muscle integrity and contractility were evaluated using ultrasound by comparing the change in rectus abdominis muscle dimensions between contractile and relaxed states. The BREAST-Q was used to score patients' subjective satisfaction. Clinical and radiographic hernia rates were also calculated.

RESULTS

Analysis of 26 paired rectus abdominis muscles revealed no significant change in muscle size from preoperative to postoperative values. Furthermore, dimensional change from contractile to relaxed states postoperatively was similar for paired operative and nonoperative rectus abdominis muscles. BREAST-Q scores indicated a high degree of satisfaction in abdominal well-being, breast satisfaction, and surgical experience domains. There were no clinical or radiographic abdominal wall hernias noted.

CONCLUSIONS

The DIEP flap is an effective surgical procedure with minimal abdominal wall morbidity that is associated with no measurable loss in rectus abdominis size and contractile function postoperatively. Patients are highly satisfied with their abdominal function postoperatively using this technique.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Donor-site morbidities in 615 patients after breast reconstruction using a free muscle-sparing type I transverse rectus abdominis myocutaneous flap: a single surgeon experience

Transverse rectus abdominis myocutaneous flap is one of the most commonly used reconstruction tools after oncological mastectomy. However, post-operative donor-site morbidities remain an issue to be addressed. In this study, we retrospectively reviewed patients with either immediate or delayed breast reconstruction using a free muscle-sparing type I transverse rectus abdominis myocutaneous flap only, performed by a single surgeon, regarding the donor-site morbidity. From January 2012 to July 2017, the study subjects summed up to 615 patients, in a single institution. Preoperative planning and actual surgical techniques were outlined including the evaluation of the location of the perforators using a three-dimensional abdominal computed tomography angiography scan, minimal fascia sacrifice, beveled dissection and minimization of the tension on the central abdomen during closure. During a 1-year follow-up, a total of 33 patients (5.4%) were complicated with any donor-site morbidity. Those in need of secondary revision on their donor-sites accounted for 23 patients (69.7%). No factor was found statistically significant to increase the risk of donor-site morbidity. Many surgical techniques have been devised for closure of the donor-site in transverse rectus abdominis myocutaneous flap patients. And, several factors have been proposed as increasing the risk of donor-site morbidity. Although all the suggested predictive factors failed to prove its significance on increasing the risk, a set of preoperative planning and surgical techniques employed in our study has proven to be both safe and efficient in lowering the postoperative donor-site morbidities.

Complications and Patient-Reported Outcomes after Abdominally Based Breast Reconstruction: Results of the Mastectomy Reconstruction Outcomes Consortium Study

BACKGROUND

Abdominal flap reconstruction is the most popular form of autologous breast reconstruction. The current study compared complications and patient-reported outcomes after pedicled transverse rectus abdominis myocutaneous (TRAM), free TRAM, deep inferior epigastric perforator (DIEP), and superficial inferior epigastric artery (SIEA) flaps.

METHODS

Patients undergoing abdominally based breast reconstruction at 11 centers were prospectively evaluated for abdominal donor-site and breast complications. Patient-reported outcomes were measured by the BREAST-Q and Patient-Reported Outcomes Measurement Information System surveys. Mixed-effects regression models were used to assess the effects of procedure type on outcomes.

RESULTS

Seven hundred twenty patients had 1-year follow-up and 587 had 2-year follow-up. Two years after reconstruction, SIEA compared with DIEP flaps were associated with a higher rate of donor-site complications (OR, 2.7; p = 0.001); however, SIEA flaps were associated with higher BREAST-Q abdominal physical well-being scores compared with DIEP flaps at 1 year (mean difference, 4.72, on a scale from 0 to 100; p = 0.053). This difference was not significant at 2 years. Abdominal physical well-being scores at 2 years postoperatively were lower in the pedicled TRAM flap group by 7.2 points (p = 0.006) compared with DIEP flaps and by 7.8 points (p = 0.03) compared with SIEA flaps, and in the free TRAM flap group, scores were lower by 4.9 points (p = 0.04) compared with DIEP flaps. Bilateral reconstruction had significantly lower abdominal physical well-being scores compared with unilateral reconstruction.

CONCLUSIONS

Although all abdominally based flaps are viable breast reconstruction options, DIEP and SIEA flaps are associated with higher abdominal physical well-being than pedicled and free TRAM flaps. Although SIEA flaps offer the advantage of not violating the fascia, higher rates of donor-site complications may diminish patient satisfaction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Meta-analysis of flap perfusion and donor site complications for breast reconstruction using pedicled versus free TRAM and DIEP flaps

OBJECTIVES

The transverse rectus abdominis musculocutaneous (TRAM) flap is an important option for breast reconstruction. Several studies have recently evaluated whether a greater number of complications result from the use of pedicled TRAM (pTRAM) flaps versus either free TRAM (fTRAM) flaps or deep inferior epigastric artery perforator (DIEP) flaps. To clarify the evidence regarding this issue, we performed an objective meta-analysis of published studies.

MATERIALS AND METHODS

A literature search of articles published between January 1, 1990, to January 1, 2017 was performed using the PubMed, EMBASE, Scopus, and Cochrane databases. Heterogeneity was statistically analyzed, and fixed effects and random effects models were used as appropriate.

RESULTS

Eleven articles comparing pedicled TRAM (pTRAM) flaps with either free TRAM (fTRAM) or DIEP flaps were included. The articles evaluated a total of 3968 flaps, including 1891 pTRAM flaps, 866 fTRAM flaps, and 1211 DIEP flaps. Patients with fTRAM flaps had a significantly lower risk of fat necrosis and partial flap necrosis than those with pTRAM flaps. No difference was observed in total flap necrosis and hernia or bulge between fTRAM and pTRAM flaps. No difference was noted in flap complications between DIEP and pTRAM flaps except for hernia or bulge..

CONCLUSION

Although pTRAM flaps are being replaced by fTRAM and DIEP flaps, which exhibit fewer complications related to flap ischemia and donor site morbidity, it was unclear from the literature which flap type was most beneficial regarding flap vascularity and donor site morbidity. Hence, surgeons should choose the appropriate option based on their preferences and on patient factors..

Consensus Review of Optimal Perioperative Care in Breast Reconstruction: Enhanced Recovery after Surgery (ERAS) Society Recommendations

BACKGROUND

Enhanced recovery following surgery can be achieved through the introduction of evidence-based perioperative maneuvers. This review aims to present a consensus for optimal perioperative management of patients undergoing breast reconstructive surgery and to provide evidence-based recommendations for an enhanced perioperative protocol.

METHODS

A systematic review of meta-analyses, randomized controlled trials, and large prospective cohorts was conducted for each protocol element. Smaller prospective cohorts and retrospective cohorts were considered only when higher level evidence was unavailable. The available literature was graded by an international panel of experts in breast reconstructive surgery and used to form consensus recommendations for each topic. Each recommendation was graded following a consensus discussion among the expert panel. Development of these recommendations was endorsed by the Enhanced Recovery after Surgery Society.

RESULTS

High-quality randomized controlled trial data in patients undergoing breast reconstruction informed some of the recommendations; however, for most items, data from lower level studies in the population of interest were considered along with extrapolated data from high-quality studies in non-breast reconstruction populations. Recommendations were developed for a total of 18 unique enhanced recovery after surgery items and are discussed in the article. Key recommendations support use of opioid-sparing perioperative medications, minimal preoperative fasting and early feeding, use of anesthetic techniques that decrease postoperative nausea and vomiting and pain, use of measures to prevent intraoperative hypothermia, and support of early mobilization after surgery.

CONCLUSION

Based on the best available evidence for each topic, a consensus review of optimal perioperative care for patients undergoing breast reconstruction is presented.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Silk based bioinks for soft tissue reconstruction using 3-dimensional (3D) printing with in vitro and in vivo assessments

In the field of soft tissue reconstruction, custom implants could address the need for materials that can fill complex geometries. Our aim was to develop a material system with optimal rheology for material extrusion, that can be processed in physiological and non-toxic conditions and provide structural support for soft tissue reconstruction. To meet this need we developed silk based bioinks using gelatin as a bulking agent and glycerol as a non-toxic additive to induce physical crosslinking. We developed these inks optimizing printing efficacy and resolution for patient-specific geometries that can be used for soft tissue reconstruction. We demonstrated in vitro that the material was stable under physiological conditions and could be tuned to match soft tissue mechanical properties. We demonstrated in vivo that the material was biocompatible and could be tuned to maintain shape and volume up to three months while promoting cellular infiltration and tissue integration.

Breast reconstruction with single-pedicle TRAM flap in breast cancer patients with low midline abdominal scar

Breast reconstruction with transverse rectus abdominis myocutaneous (TRAM) flap is challenging in patients with low midline abdominal scar. In this study, we aimed to investigate the clinical feasibility of immediate breast reconstruction using single-pedicle TRAM (SP-TRAM) flaps in patients with low midline abdominal scar. There were 4 strict selection criteria: 1) presence at least 3 perforators on the pedicle side; 2) perforators with regional average flow velocity of >20 cm/s; 3) upper edge of the abdominal scar at least 4 cm from the umbilicus; and 4) scar age >1 year. Eight breast cancer patients with low midline abdominal scar (scar group) and 20 without (control group) underwent immediate breast reconstruction with SP-TRAM flaps consisting of zone I and III and zone II tissues. Flap complications, donor-site complications, and cosmetic results were compared between the two groups. All flaps survived and both groups presented similar flap and donor site complications, including fat necrosis, seroma, hematoma, infection, delayed wound healing, and abdominal hernia, and patients in both groups had similar aesthetic results (p > 0.05). Thus, the study demonstrated that breast reconstruction using SP-TRAM flap was a safe approach in carefully selected patients with low midline abdominal scar.

Creation of a Large Adipose Tissue Construct in Humans Using a Tissue-engineering Chamber: A Step Forward in the Clinical Application of Soft Tissue Engineering

Tissue engineering is currently exploring new and exciting avenues for the repair of soft tissue and organ defects. Adipose tissue engineering using the tissue engineering chamber (TEC) model has yielded promising results in animals; however, to date, there have been no reports on the use of this device in humans. Five female post mastectomy patients ranging from 35 to 49 years old were recruited and a pedicled thoracodorsal artery perforator fat flap ranging from 6 to 50 ml was harvested, transposed onto the chest wall and covered by an acrylic perforated dome-shaped chamber ranging from 140 to 350 cm³. Magnetic resonance evaluation was performed at three and six months after chamber implantation. Chambers were removed at six months and samples were obtained for histological analysis. In one patient, newly formed tissue to a volume of 210 ml was generated inside the chamber. One patient was unable to complete the trial and the other three failed to develop significant enlargement of the original fat flap, which, at the time of chamber explantation, was encased in a thick fibrous capsule. Our study provides evidence that generation of large well-vascularized tissue engineered constructs using the TEC is feasible in humans.

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Tissue engineering has the potential to offer exciting alternatives for the repair of soft tissues and organ development,

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The tissue-engineering chamber has been shown to support tissue growth and the generation of specialized organs in animals.

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Here we report on the use of this chamber in humans for the successful generation of new adipose tissue.

Tissue engineering has traditionally relied on the combination of cells and scaffolds, which are subsequently implanted into the patient. However, such paradigm is limited to tissues that are thin enough to rely on diffusion for survival or that have a low metabolic rate. The tissue-engineering chamber represents an interesting approach to circumvent these obstacles, as it is able to support the growth of well-vascularized blocks of specialized tissues of varying kinds. This work presents the use of such chamber in five human patients, one of which generated a large three-dimensional well-vascularized piece of adipose tissue, probably the largest and thickest engineered tissue construct reported to date.

"Mini-Flow-Through" Deep Inferior Epigastric Perforator Flap for Breast Reconstruction with Preservation of Both Internal Mammary and Deep Inferior Epigastric Vessels

This procedure was developed for preservation of the rectus muscle components and deep inferior epigastric vessel after deep inferior epigastric perforator (DIEP) flap harvesting. A 53-year-old woman with granuloma caused by silicone injection underwent bilateral nipple-sparing mastectomies and immediate reconstruction with "mini-flow-through" DIEP flaps. The flaps were dissected based on the single largest perforator with a short segment of the lateral branch of the deep inferior epigastric vessel that was transected as a free flap for breast reconstruction. The short segments of the donor deep inferior epigastric vessel branch are primarily end-to-end anastomosed to each other. A short T-shaped pedicle mini-flow-through DIEP flap is interposed in the incised recipient's internal mammary vessels with two arterial and four concomitant venous anastomoses. Although it requires multiple vascular anastomoses and a short pedicle for the flap setting, the mini-flow-through DIEP flap provides a large pedicle caliber, enabling safer microsurgical anastomosis and well-vascularized tissue for creating a natural breast without consuming time or compromising the rectus muscle components and vascular flow of both the deep inferior epigastric and internal mammary vessels.