Relationship between Venous Congestion and Intraflap Venous Anatomy in DIEP Flaps Using Contrast-Enhanced Magnetic Resonance Angiography:

Indocyanine Green Angiography for Detecting Quantitative Perfusion Changes in Deep Inferior Epigastric Perforator Flap Breast Reconstruction With Second Venous Drainage

BACKGROUND

This study aims to compare perfusion dynamics using indocyanine green videoangiography before and after the creation of a second venous anastomosis between the superficial inferior epigastric vein and the retrograde internal mammary vein (IMV) in deep inferior epigastric perforator (DIEP) flap breast reconstructions.

METHODS

Indocyanine green videoangiography performed during DIEP flap reconstructions was analyzed prospectively. The areas of interest were above the perforators with the highest intensity (complete perfusion), the most distal lateral edge of the flap (partial perfusion), and the next lowest intensity (ischemic). We compared the zone intensities before and after the second venous anastomosis, assessing venous drainage patency and functionality. Patient characteristics, operative details, and complications were collected.

RESULTS

Seven patients (10 breasts) underwent DIEP reconstruction. Mean age was 54.5 ± 12.4 years. Mean operative duration was 575.5 ± 172.6 minutes. Donors included DIEV (n = 10, 100.0%), superficial inferior epigastric vein (n = 9, 90.0%), and superficial circumflex epigastric vein (n = 1, 10.0%). All DIEVs were anastomosed to the antegrade IMV (n = 10, 100.0%). Superficial inferior epigastric veins were anastomosed to the retrograde IMV (n = 10, 100.0%). Mean peak intensities of the complete perfusion zone before and after the second venous anastomosis were 160.7 ± 42.1 and 188 ± 42.1, respectively (P = 0.163). Mean peak intensities of the partial perfusion zone were 100.8 ± 21.5 and 152 ± 31.5, respectively (P < 0.001). Mean peak intensities of the ischemic zone were 90.4 ± 37.4 and 143.4 ± 45.3, respectively (P = 0.012).

CONCLUSION

These findings highlight the potential benefits of the super drainage technique in enhancing perfusion and reducing complications, emphasizing the need for further investigation and consideration of this technique in clinical practice.

MRA for Preoperative Planning and Postoperative Management of Perforator Flap Surgeries: A Review

Perforator flap magnetic resonance angiography (MRA) has emerged as a widely accepted and preferred modality for perforator flap mapping at several institutions. Autologous perforator flaps are a type of reconstructive microsurgical technique that involves transferring skin and fat from one part of the patient's body to another to replace tissue lost due to trauma, cancer resection, or other reasons. Autologous perforator flaps are based on a specific perforating blood vessel perfusing the transferred tissue. Hence, the surgery relies on the precise identification and mapping of perforating vessels to ensure successful outcomes. With its superior soft tissue contrast and multiplanar imaging capabilities, MRA has shown great potential in providing accurate and detailed visualization of perforator anatomy, size, and course. This review article summarizes the current literature on perforator flap MRA, including its technical considerations, imaging protocols, postprocessing, and reporting, specifically for autologous breast reconstructions. The advantages and limitations of MRA in evaluating perforator flaps are discussed, including its role in preoperative planning, intraoperative guidance, and postoperative assessment. Anatomy, brief surgical technique, specific technical modifications, and reporting of most commonly performed autologous breast flaps are described. Recent advancements in Perforator flap surgery and MRA techniques are discussed. Additionally, we examine the emerging role of artificial intelligence and machine learning in improving the accuracy and efficiency of perforator flap MRA interpretation. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 5.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

PROSPERO (CRD42022353591).

A Systematic Approach to Intraoperative Venous Congestion in the Deep Inferior Epigastric Artery Perforator (DIEAP) Flap

The deep Inferior epigastric artery perforator (DIEAP) flap is currently the gold standard for autologous breast reconstruction. This flap is susceptible to venous congestion, which can result in partial or complete flap loss. Apart from external causes, venous congestion may be caused by the flap's vascular architecture, either due to a dominance of the superficial venous system or due to impaired communication between the superficial and deep venous systems. This inefficient vascular architecture can be detected during surgery, and the venous outflow drainage can be improved through several techniques. We present two case reports of intraoperative venous congestion. In the first case, we performed an intra-flap rerouting, through a venous anastomosis between the superficial and the deep venous systems. In the second case, an extra-flap rerouting was executed, through a venous anastomosis between the superficial venous system and a recipient vein. We present the current institutional approach to DIEAP flap breast reconstruction, incorporating surgical insights for addressing intraoperative venous congestion.

Superficial outside-flap shunt (SOS) is associated with a low incidence of postoperative DIEP flap venous congestion: A single-institution retrospective cross-sectional study

INTRODUCTION

Venous congestion burdens up to 15% of deep inferior epigastric artery perforator (DIEP) flap breast reconstructions. For these cases, venous augmentation by superficial outside shunt (SOS) is associated with 100% success in secondary salvage surgeries. Intraoperative venous augmentation using other techniques yields a 0.3% rate of return to theater due to venous congestion, but there is no evidence assessing the effectiveness of the SOS technique applied preventively. Comparing this preventive approach to data prior to its implementation, we expect to find a reduced number of venous congested flaps with reduced flap losses and revision surgeries.

PATIENTS AND METHODS

This retrospective cross-sectional study involved DIEP flap breast reconstructions performed between 2011 and 2020. The control group included patients receiving additional venous anastomosis as a secondary salvage procedure. The "preventive SOS group" included patients who received preventive SOS during the main surgery. Age, body mass index (BMI), pregnancies, perioperative treatments (neoadjuvant or adjuvant chemo or radiotherapy), follow-up complications (arterial ischemia, venous congestion, hematomas, partial/total flap loss), and revision surgeries (breast debridement, flap remodeling) were recorded and compared.

RESULTS

Within 695 flaps performed, 397 flaps were included in the control group, and 298 flaps were included in the preventive SOS group. The groups were homogeneous for age (p = 0.418), BMI (p = 0.747), and flap weight (p = 0.064). Fifty-one flaps (12.8%) in the control group compared to zero (0.0%) in the preventive SOS group required return to theater (p < 0.001).

CONCLUSIONS

We reported encouraging preliminary results for SOS to prevent DIEP flap venous congestion. These results must be validated prospectively.

Creating a context for recipient vessel selection in deep inferior epigastric perforator flap breast reconstruction

BACKGROUND

In autologous tissue breast reconstruction, recipient vessels are important for artery perfusion and venous drainage to ensure free flap survival. There are insufficient clinical outcomes to select efficient recipient vessels in bi-pedicled deep inferior epigastric perforator (DIEP) flap reconstruction.

METHODS

We presented a retrospective observational series of 108 patients regarding the diameter, anastomosis time, and re-anastomosis rate in internal mammary (IM), circumflex scapular (CS), thoracodorsal (TD), thoracoacromial (TA), lateral thoracic (LT), and internal mammary perforator (IMP) vessels of bi-pedicled DIEP flaps for breast reconstruction after mastectomy. The outcomes were the vessel re-anastomosis rate, flap failure rate, vessel anastomosis time, and complications. Data were gleaned from the chi-square test, Fisher's test, and analysis of variance using Scheffe's test as a post hoc analysis. The level of significance was p < 0.05.

RESULTS

There were no significant differences in the diameters of the artery, first vein, and second vein across the recipient vessels (p > 0.05). However, the anastomosis time was longer in IM and TA than in CS, TD, and LT (p < 0.001). Also, there were no significant differences for re-anastomosis, flap necrosis, and fat necrosis among different recipient vessels (p > 0.05).

CONCLUSIONS

Because of the altered mastectomy incisions, this study provides complete anatomical vascular properties and suggests that altering recipient vessel selection for bi-pedicled DIEP flaps can shorten anastomosis time and better conceal scars.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Use of the superficial inferior epigastric vein in breast reconstruction with a deep inferior epigastric artery perforator flap

Background

Autologous breast reconstruction is highly regarded in reconstructive surgery after mastectomy. DIEP flap reconstruction represents the gold standard for autologous breast reconstruction. The major advantages of DIEP flap reconstruction are its adequate volume, large vascular caliber and pedicle length. Despite reliable anatomy, there are procedures where the plastic surgeon's creativity is required, not only to shape the new breast, but also to overcome microsurgical challenges. An important tool in these cases is the superficial epigastric vein (SIEV).

Methods

150 DIEP flap procedures performed between 2018 and 2021 were retrospectively evaluated for SIEV use. Intraoperative and postoperative data were analyzed. Rate of anastomosis revision, total and partial flap loss, fat necrosis and donor site complications were evaluated.

Results

In a total of 150 breast reconstructions with a DIEP flap performed in our clinic, the SIEV was used in 5 cases. The indication for using the SIEV was to improve the venous drainage of the flap or as a graft to reconstruct the main artery perforator. Among the 5 cases, no flap loss occurred.

Conclusions

Use of the SIEV is an excellent method to expand the microsurgical options in breast reconstruction with DIEP flap surgery. It provides a safe and reliable procedure to improve venous outflow in cases of inadequate outflow from the deep venous system. The SIEV could also provide a very good option for fast and reliable application as an interposition device in case of arterial complications.

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

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

The influence of venous system patterns on DIEP flap viability for breast reconstruction

A deep inferior epigastric artery perforator (DIEP) flap has unique variations in the anatomy of the vascular supply, and this idea has been adapted to the venous system. Venous system patterns, including connections between the superficial and deep inferior epigastric vein (SDC) or connections of the superficial inferior epigastric vein across the midline-crossing linking veins (MCLV), have gradually become recognized as a cause of fat necrosis and induration due to venous congestion. Therefore, it is important to select patients who are appropriate for transplantation by evaluating blood flow in the flap based on these patterns. The subjects were 52 consecutive patients who underwent DIEP flap breast reconstruction. Relationships of fat necrosis and induration of a transplanted flap and venous system patterns (presence of SDC on the contralateral side: cSDC or MCLV, direction and diameter of perforator vein) in the flap were investigated. Logistic regression and univariate and multivariate analyses were used to identify predictors of fat necrosis and induration of the flap. Fat necrosis and induration were detected in 17.4 and 34.8% of cases, respectively. These incidences were significantly linked to the absence of cSDC and MCLV patterns in the flap. Patients without a cSDC or MCLV pattern had harder fat tissue in Zone II, especially in the distal portion. These results suggest that the absence of a cSDC or MCLV pattern causes complications such as fat necrosis and induration in a transplanted flap. If neither pattern is detected before surgery, improvement of venous drainage is recommended.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

How to Design and Harvest a Propeller Flap

Propeller flaps are local flaps based either on a subcutaneous pedicle, a single perforator, or vessels entering the flap in such a way so as to allow the flap to rotate on their axis. Depending on the kind of pedicle and the anatomical area, the preoperative investigation and the harvesting techniques may vary. An adequate knowledge of skin and subcutaneous tissue perfusion in the different areas of the body is very important to plan a propeller flap to be successful. The surgeon should begin by finding the most suitable perforators in the area surrounding the defect using available technology. The position, size, and shape of the flap are planned about this point. For perforator-pedicled propeller flaps, the procedure starts with an exploration from the margins of the defect or through a dedicated incision to visualize any perforators in the surroundings. The most suitable perforator is selected and isolated, the skin island is replanned, and the flap is harvested and rotated into the defect. The variations in surgical technique for other types of propellers and in specific anatomical areas are also described. Compared with free flaps, propeller flaps have the advantage of a simpler, shorter operation, without the need for a recipient vessel for microanastomosis. Yet, from a technical point of view, an adequate experience in dissecting perforators and the use of magnifying glasses are almost always required.

Refining our knowledge of macrovascular arteriovenous shunts (MAS): Anatomical and pathological studies

BACKGROUND

The macrovascular arteriovenous shunt (MAS) connecting the deep inferior epigastric artery (DIEA) and superficial inferior epigastric vein (SIEV) in the abdominal wall has already been identified as an important structure, and further study has been deemed necessary to establish its role and function.

METHODS

Review of CT angiograms (CTA) of 38 female patients was undertaken, by means of analysis of fine-cut axial images and three-dimensional image reconstructions of the cutaneous vasculature of the deep and superficial vasculature. In vivo dissection of the structure was also performed to establish its communications. Lastly, a histopathological analysis was carried out to investigate its intrinsic structure and function.

RESULTS

The MAS was identified in both sides of the abdomen in all subjects and the diameter ranges from 0.72 to 2.81 mm with a median diameter of 1.28 mm. In vivo dissection revealed it as a distinct structure connecting the DIEA and SIEV. Pathological analysis showed that it has characteristics of both elastic and muscular arteries, which constitutes a new vessel.

CONCLUSION

These further investigations have yielded a better understanding of the MAS shunt, its position, structure and function. This can be of crucial importance to reconstructive surgeons when raising the DIEP flap.

Interdisciplinary Treatment of Breast Cancer After Mastectomy With Autologous Breast Reconstruction Using Abdominal Free Flaps in a University Teaching Hospital-A Standardized and Safe Procedure

Background: Breast cancer is the most common malignancy in women. The interdisciplinary treatment is based on the histological tumor type, the TNM classification, and the patient's wishes. Following tumor resection and (neo-) adjuvant therapy strategies, breast reconstruction represents the final step in the individual interdisciplinary treatment plan. Although manifold flaps have been described, abdominal free flaps, such as the deep inferior epigastric artery perforator (DIEP) or the muscle-sparing transverse rectus abdominis myocutaneous (ms-TRAM) flap, are the current gold standard for autologous breast reconstruction. This retrospective study focuses on the safety of autologous breast reconstruction upon mastectomy using abdominal free flaps. Methods: From April 2012 until December 2018, 193 women received 217 abdominal free flaps for autologous breast reconstruction at the University Hospital of Erlangen. For perforator mapping, we performed computed tomography angiography (CTA). Venous anastomosis was standardized using a ring pin coupler system, and flap perfusion was assessed with fluorescence angiography. A retrospective analysis was performed based on medical records, the surgery report, and follow-up of outpatient course. Results: In most cases, autologous breast reconstruction was performed as a secondary reconstructive procedure after mastectomy and radiotherapy. In total, 132 ms1-TRAM, 23 ms2-TRAM, and 62 DIEP flaps were performed with 21 major complications (10%) during hospital stay including five free flap losses (2.3%). In all cases of free flap loss, we found an arterial thrombosis as the main cause. In 24 patients a bilateral breast reconstruction was performed without free flap loss. The majority of free flaps (96.7%) did not need additional supercharging or turbocharging to improve venous outflow. Median venous coupler size was 2.5 mm (range, 1.5-3.5 mm). Conclusion: Using CTA, intraoperative fluorescence angiography, titanized hernia meshes for rectus sheath reconstruction, and venous coupler systems, autologous breast reconstruction with DIEP or ms-TRAM free flaps is a safe and standardized procedure in high-volume microsurgery centers.

CTA in preoperative planning for DIEP breast reconstruction: what the reconstructive surgeon wants to know. A modified Delphi study

AIM

To gather expert reconstructive surgical opinion to define and rank the surgically most important anatomy and provide guidance for report content to radiologists when reading a preoperative computed tomography angiography (CTA).

MATERIALS AND METHODS

A modified Delphi approach was used, involving a panel of 13 microsurgery experts across North America. Data from three consecutive online surveys were collected and returned to the respondents in the subsequent survey, allowing each respondent to see the range of opinions from other field experts.

RESULTS

Response rates were 62%, 77%, and 69% for each of the three survey rounds, respectively. The panel identified that the most important perforator characteristics in selecting the optimal perforator are diameter of the vein, perforator location within the flap, and diameter of the artery, respectively. The stated preference was for perforators located below the umbilicus. If no suitable perforator was located below the umbilicus, the panel would consider perforators up to 2 cm above the umbilicus. The most important considerations for the preoperative radiology planning report are: the size of the perforator vein, perforator location relative to landmarks, and the size of the perforator artery.

DISCUSSION

Based on the panel of expert reconstructive microsurgeons, the most surgically important anatomical considerations to be assessed and included in preoperative CTA reports for DIEP flap breast reconstruction were determined. The recommendations for reporting of preoperative DIEP breast reconstructions are presented, which, in consultation with local surgeons, can be used to form a template for reporting.

Utilisation of contrast-enhanced magnetic resonance angiography in the assessment of deep inferior epigastric artery perforator flap for breast reconstruction surgery

AIM

To identify and characterise the ideal-sized (defined as at least 2.7 mm based on the experience of plastic surgeons at Hull Royal Infirmary) perforators using magnetic resonance angiography (MRA). The study also evaluated a presumption that perforators on the left are generally larger than on the right.

MATERIALS AND METHODS

Fifty consecutive patients who had undergone MRA prior to deep inferior epigastric perforator (DIEP) reconstruction were included. MRA acquisition sequences, MRA images, radiologist reports, and surgical entry database were reviewed retrospectively. Intraoperative findings were compared. The diameter and characteristics of the perforators fulfilling the criteria of being "ideal-sized", at least 2.7 mm were collected. Wilcoxon's test was used to compare the size of the left and right perforators.

RESULTS

Ninety-three ideal-sized perforators were identified (diameter of 2.8-4.2 mm). Fifty-one of these were located on the left, and 42 on the right. The left perforators were indeed larger than the right (Wilcoxon's test, p=0.017). Most of the perforators were found in the superior region and medial rows. Additionally, lateral row perforators were observed to have a shorter intramuscular course.

CONCLUSION

Contrast-enhanced MRA is a useful preoperative imaging technique to locate ideal DIEPs for breast reconstruction. Perforators on the left were found to be larger than the right, and more ideal-sized perforators were located on the left.

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.

MRA of the skin: mapping for advanced breast reconstructive surgery

Autologous breast reconstruction using muscle-sparing free flaps are becoming increasingly popular, although microvascular free flap reconstruction has been utilised for autologous breast reconstructions for >20 years. This innovative microsurgical technique involves meticulous dissection of artery-vein bundle (perforators) responsible for perfusion of the subcutaneous fat and skin of the flap; however, due to unpredictable anatomical variations, preoperative imaging of the donor site to select appropriate perforators has become routine. Preoperative imaging also reduces operating time and enhances the surgeon's confidence in choosing the appropriate donor site for harvesting flaps. Although computed tomography angiography has been widely used for preoperative imaging, concerns over excessive exposure to ionising radiation and poor iodinated contrast agent enhancement of the intramuscular perforator course has made magnetic resonance angiography, the first choice imaging modality in our centre. Magnetic resonance angiography with specific post-processing of the images has established itself as a reliable method for mapping tiny perforator vessels. Multiple donor sites can be imaged in a single setting without concern for ionising radiation exposure. This provides anatomical information of more reconstruction donor site options, so that a surgeon can design a flap of tissue centralised around the best perforator, as well as a back-up perforator, and even a back-up flap option located on a different region of the body. This information is especially helpful in patients with a history of scar tissue from previous surgeries, where the primary choice perforator is found to be damaged or unsuitable intraoperatively. In addition, chest magnetic resonance angiography evaluates recipient site blood vessel suitability including vessel diameters, course, and branching patterns. In this article we provide a broad overview of various skin flaps, clinical indications, advantages and disadvantages of each of these flaps, basic imaging technique, along with advanced sequences for visualising tiny arteries in the groin and in the chest. Post-processing techniques, structure of the report and how automation of the reporting system improves workflow is described. We also describe applications of magnetic resonance angiography in postoperative imaging.

MRI anatomical preoperative evaluation of distally based peroneus brevis muscle flap in reconstructive surgery of the lower limb

BACKGROUND

The distally based peroneus brevis muscle flap has proved to be a simple solution for small- to moderate-sized wounds of the lower limb. The length of the muscle belly suitable for coverage is a crucial parameter. In this study, we evaluated the capability of 3D MRI of the lower limb to measure it preoperatively.

METHODS

Between 2008 and 2017, 32 patients with lower limb defects underwent preoperative MRI to measure the peroneus brevis muscle length. All patients underwent reconstruction, and the muscle was measured again intraoperatively during surgical dissection. Surgical measurements were then compared to the MRI ones.

RESULTS

MRI measures of the peroneus brevis muscle belly ranged from 9 to 21 cm (μ = 14.44 ± 3.43 cm), and intraoperative measures ranged from 9 to 20 cm (μ = 14.2 ± 2.3 cm). Thirty of 32 intraoperative measures corresponded to the MRI ones (variation = ± 1 cm, r = 0.92, p = 0.002). One patient showed an intraoperative muscle length 3 cm shorter than the MRI measure, and another patient had intraoperative muscle length 3 cm longer than the MRI one. All flaps survived, and no secondary local flap coverage was required, with no flap-related complication, limited donor site morbidity, and acceptable patient discomfort.

CONCLUSIONS

The reverse peroneus brevis muscle flap is a versatile alternative to free flap reconstruction in small- to moderate-sized defects of the lower limb. Preoperative 3D MRI is accurate to evaluate the anatomy of the muscle when performed by an expert radiologist. In our experience, it should become part of preoperative workup before performing a peroneus brevis flap procedure.

The Influence of a Pfannenstiel Scar on Venous Anatomy of the Lower Abdominal Wall and Implications for Deep Inferior Epigastric Artery Perforator Flap Breast Reconstruction

BACKGROUND

A Pfannenstiel incision involves the obstruction of superficial venous pathways and functional diversion of flow through alternative pathways and adjacent vessels. This study investigated the effect of a prior Pfannenstiel incision on venous anatomy of the lower abdominal wall; specifically, the superficial inferior epigastric vein (SIEV), using computed tomographic angiography.

METHODS

A case-control study was performed of 50 patients with Pfannenstiel scars and 50 age-matched, body mass index-matched control patients without Pfannenstiel scars. The authors compared the number of direct/indirect and total communications between the SIEV and deep inferior epigastric artery perforator (DIEP) venae comitantes, midline crossover, and other SIEV-related anatomical changes by using computed tomographic angiography. Flap-related clinical outcomes and donor-site-related complications were also assessed.

RESULT

The median number of direct and total communications between the SIEV and DIEP venae comitantes in the study group was greater than in the control group. The percentage of SIEVs having more than two branching patterns per hemiabdomen was significantly higher in the study group than in the control group. The study group also showed a significantly lower rate of fat necrosis compared with the control group (p = 0.03). The rate of donor-site seroma was significantly higher in the study group.

CONCLUSION

This study suggests that the presence of a Pfannenstiel scar may promote the development of direct and total communications between the SIEV and DIEP venae comitantes and branching within the SIEV in the lower abdominal wall, which may facilitate venous drainage of adipose tissue in DIEP flap breast reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Advances in imaging technologies for planning breast reconstruction

The role and choice of preoperative imaging for planning in breast reconstruction is still a disputed topic in the reconstructive community, with varying opinion on the necessity, the ideal imaging modality, costs and impact on patient outcomes. Since the advent of perforator flaps their use in microsurgical breast reconstruction has grown. Perforator based flaps afford lower donor morbidity by sparing the underlying muscle provide durable results, superior cosmesis to create a natural looking new breast, and are preferred in the context of radiation therapy. However these surgeries are complex; more technically challenging that implant based reconstruction, and leaves little room for error. The role of imaging in breast reconstruction can assist the surgeon in exploring or confirming flap choices based on donor site characteristics and presence of suitable perforators. Vascular anatomical studies in the lab have provided the surgeon a foundation of knowledge on location and vascular territories of individual perforators to improve our understanding for flap design and safe flap harvest. The creation of a presurgical map in patients can highlight any abnormal or individual anatomical variance to optimize flap design, intraoperative decision-making and execution of flap harvest with greater predictability and efficiency. This article highlights the role and techniques for preoperative planning using the newer technologies that have been adopted in reconstructive clinical practice: computed tomographic angiography (CTA), magnetic resonance angiography (MRA), laser-assisted indocyanine green fluorescence angiography (LA-ICGFA) and dynamic infrared thermography (DIRT). The primary focus of this paper is on the application of CTA and MRA imaging modalities.

Suprascarpal fat pad thickness may predict venous drainage patterns in abdominal wall flaps

BACKGROUND

Abdominal wall flaps are routinely used in reconstructive procedures. In some patients inadequate venous drainage from the deep vein may cause fat necrosis or flap failure. Occasionally the superficial inferior epigastric vessels (SIEV) are of sufficient size to allow for microvascular revascularization. This study looked at the ratio of the sub- and suprascarpal fat layers, the number of deep system perforators, and SIEV diameter to determine any correlation of the fat topography and SIEV.

METHODS

50 abdominal/pelvic CT angiograms (100 hemiabdomens) were examined in women aged 34-70 years for number of perforators, SIEV diameter, and fat pad thickness above and below Scarpa's fascia. Data was analyzed using multivariate model.

RESULTS

The average suprascarpal and subscarpal layers were 18.6 ± 11.5 mm and 6.2 ± 7.2 mm thick, respectively. The average SIEV diameter was 2.06 ± 0.81 mm and the average number of perforators was 2.09 ± 1.03 per hemiabdomen. Hemiabdomens with suprascarpal thickness>23 mm had greater SIEV diameter [2.69 mm vs. 1.8 mm (P < 0.0001)] The fat layer thickness did not correlate with the number of perforators. Neither subscarpal fat thickness nor suprascarpal-to-subscarpal fat layer thickness correlated significantly with SIEV caliber or number of perforators in multivariate model.

CONCLUSIONS

Suprascarpal fat pad thicker than 23 mm had larger SIEVs irrespective of the number of deep system perforators. This may indicate a cohort of patients at risk of venous congestion from poor venous drainage if only the deep system is revascularized. We recommend harvesting the SIEV in patients with suprascarpal fat pad >23 mm to aid in superficial drainage.

Anatomic and physiological fundamentals for autologous breast reconstruction

The success of autologous tissue transfer is reliant on adequate blood supply and as we endeavour to tailor our reconstructive options through our flap choices and design. Autologous breast reconstruction has made substantial progress over the years and the evolution of refinements over the last 30 years has allowed flaps to be based on specific perforators. The ultimate goal of breast reconstruction following mastectomy is to match optimal tissue replacement with minimal donor-site expenditure. In parallel surgeons will seek ways to ensure safe flap design and harvest while maintaining predictability and reliable tissue perfusion. Better understanding of the vascular anatomy and physiology of the cutaneous circulation of soft tissues, and that of patterns of blood flow from individual perforator has provided insight to advance perforator flap harvest and modifications in flap design. The aim of this article is to review the principles of blood supply and flap design exemplified through common flaps used in autologous breast reconstructive surgery, to better understand approaches for safe flap harvest and transfer of well perfused tissue.

Hydrogen peroxide priming of the venous architecture: a new technique that reveals the underlying anatomical basis for venous complications of DIEP, TRAM, and other abdominal flaps

BACKGROUND

Previous studies of venous anatomy lack the detail of their arterial counterparts because of (1) the technical challenge of retrograde perfusion against competent valves and (2) anterograde venous perfusion failing to adequately delineate the area of interest. We introduced a novel technique: retrograde hydrogen peroxide priming that dilates veins and renders valves incompetent, thereby facilitating complete cadaveric venous perfusion.

METHODS

The superficial and deep venous systems of 41 hemiabdomens and 20 hemichests of unembalmed human cadavers were primed by retrograde injection with 6% hydrogen peroxide. Specimens were then injected with lead oxide contrast, radiographed, and dissected. In five hemiabdomens, the valves were mapped by dissection. Results were compared with archival venous studies of six total body injections, six abdominal lipectomy specimens, and two intraoperative venograms of delayed transverse rectus abdominis musculocutaneous flaps.

RESULTS

Unprecedented venous filling of the anterior torso was demonstrated. Two types of superficial-to-deep venous connections were defined: large venae communicantes and small venae comitantes. Venae communicantes (>2 mm) formed major connections between large superficial and deep veins, mostly within 5 cm of the umbilicus in the abdomen, the axilla and fifth or sixth intercostal space parasternally. Seventy-four percent of venae communicantes coursed with arteries greater than 1.0 mm. Four major longitudinal valved subcutaneous pathways of the superficial inferior epigastric vein and superficial circumflex iliac vein were defined bilaterally with large avalvular transverse connections in the midline and small-caliber connections laterally that explain venous complications seen sometimes in transverse abdominal flaps.

CONCLUSION

Retrograde hydrogen peroxide priming of veins in cadavers renders valves incompetent and facilitates detailed venous studies that help refine flap design and explain venous complications.

Salvage of intraoperative deep inferior epigastric perforator flap venous congestion with augmentation of venous outflow: flap morbidity and review of the literature

BACKGROUND

Breast reconstruction with deep inferior epigastric perforator (DIEP) flaps has gained considerable popularity due to reduced donor-site morbidity. Previous studies have identified the superficial venous system as the dominant outflow to DIEP flaps. DIEP flap venous congestion occurs if superficial venous outflow via the deep venous system is insufficient for effective flap drainage. Although augmentation of venous outflow through a second venous anastomosis may relieve venous congestion, effects on flap morbidity remain ill defined.

METHODS

A retrospective analysis of 1616 patients who underwent 2618 DIEP flap breast reconstructions between March 2005 and January 2012 was performed. Patients with intraoperative venous congestion underwent a second venous anastomosis. Preoperative demographic data and methods used to relieve venous congestion were recorded. Incidence of flap morbidity was calculated and compared with a group of 418 controls having 639 DIEP flap breast reconstructions with no venous congestion.

RESULTS

Venous augmentation was required to relieve venous congestion in 87 (3.3%) DIEP flaps on 81 patients. The superficial inferior epigastric vein or accompanying deep inferior epigastric venae comitantes was used to augment venous outflow. Preoperative comorbidities were similar between both groups. Patients requiring a second venous anastomosis had a longer operative time and length of hospital stay. Overall, flap morbidity, delayed wound healing, fat necrosis, and flap loss were similar to controls.

CONCLUSIONS

Arterial and venous anatomies play unique roles in flap reliability. DIEP flap venous congestion must be treated expeditiously with venous augmentation to relieve venous congestion and mitigate flap morbidity.

Preoperative imaging for perforator flaps in reconstructive surgery: a systematic review of the evidence for current techniques

BACKGROUND

Although preoperative imaging of perforator vasculature in planning microvascular reconstruction is commonplace, there has not been any clear demonstration of the evidence for this practice, or data comparing the many available modalities in an evidence-based approach. This article aims to provide an objective, evidence-based review of the literature on this subject.

METHODS

The evidence supporting the use of various modalities of imaging was investigated by performing focused searches of the PubMed and Medline databases. The articles were ranked according to the criteria set out in March 2009 Oxford Centre for Evidence-Based Medicine definitions. Endpoints comprised objective outcome data supporting the use of imaging, including flap loss, unplanned returns to theater, operative time reduction, and surgeon-reported stress.

RESULTS

The objective high level of evidence for any form of preoperative perforator imaging is low with only small number of comparative studies or case series investigating computed tomographic angiography (CTA), magnetic resonance angiography, handheld Doppler, color duplex, and classic angiography. Of all modalities, there is a growing body of level 2b evidence supporting the use of CTA.

CONCLUSION

While further multicenter trials testing hard outcomes are needed to conclusively validate preoperative imaging in reconstructive surgery, sufficient evidence exists to demonstrate that preoperative imaging can statistically improve outcomes, and that CTA is the current gold standard for perforator mapping.

Contrast-enhanced magnetic resonance angiography

With technological advances in magnetic resonance angiography (MRA), spatial resolution of 1-mm perforating vessels can reliably be visualized and accurately located in reference to patients' anatomic landmarks without exposing patients to ionizing radiation or iodinated contrast, resulting in optimal perforator selection, improved flap design, and increased surgical efficiency. As their experience with MRA in breast reconstruction has increased, the authors have made changes to their MRA protocol that allow imaging of the vasculature in multiple donor sites (buttock, abdomen, and upper thigh) in one study. This article provides details of this experience with multiple donor site contrast-enhanced MRA.

Contrast-enhanced magnetic resonance angiography for preoperative imaging in DIEP flap breast reconstruction

BACKGROUND

Contrast-enhanced magnetic resonance angiography has been shown to be very accurate for identifying the perforator size, location, and intramuscular course, and the associated venous system, without exposing the patient to ionizing radiation. This study reports the authors' experience using this imaging modality in a large patient series.

METHODS

A retrospective review of patients who had undergone preoperative contrast-enhanced magnetic resonance angiography followed by free abdominal flap breast reconstruction was conducted. The results of imaging were compared with intraoperative findings, and surgical outcomes were compared with scan data. The results were compared with control data in patients who did not undergo presurgical imaging.

RESULTS

One hundred thirty-two patients underwent contrast-enhanced magnetic resonance angiography presurgical imaging, and the results were compared with 84 controls. The imaging was found to be accurate for evaluating the perforator anatomy for free abdominal flap planning, with a high concordance between imaging and intraoperative findings. Without presurgical angiography, the ratio of deep inferior epigastric perforator (DIEP) flap-to-free transverse rectus abdominis musculocutaneous flap harvest was 0.9:1; with presurgical imaging, the ratio was 1.6:1 (p < 0.05). With presurgical angiography, there was a mean reduction in operating time of 26 minutes for unilateral DIEP flap harvest and 40 minutes for bilateral harvest, although these values were not significant. There was a significant reduction in the partial flap failure rate with preoperative imaging.

CONCLUSIONS

Presurgical imaging using contrast-enhanced magnetic resonance angiography demonstrates a high concordance with intraoperative findings. In this series, the percentage of flaps that were raised as DIEP flaps was significantly increased in patients who underwent preoperative imaging, and the partial flap failure rate was significantly reduced.

CLINICAL QUESTION/LEVEL OF EVIDENCE

: Therapeutic, III.(Figure is included in full-text article.).

Computed tomographic angiography: assessing outcomes

Perforator flaps are preferable for breast reconstruction after mastectomy in many patients. Preoperative imaging of the perforators and source vessels is desirable to reduce surgeon stress, limit donor and recipient site complications, and minimize operative time and associated costs. Computed tomographic angiography (CTA) has been shown to provide highly accurate representations of vascular anatomy with excellent spatial resolution. A critical review of the currently available literature was performed to identify the benefits of preoperative imaging (specifically CTA) in perforator flap reconstruction.