Estimation of Contralateral Perfusion in the DIEP Flap by Scoring the Midline-Crossing Vessels in Computed Tomographic Angiography

Noninvasive visualization of the midline-crossing arterial variation in the deep inferior epigastric artery perforator flap using photoacoustic tomography for application in patients with abdominal scars

BACKGROUND

The importance of the subcutaneous arterial network crossing the midline in transverse abdominal flaps has been reported. Photoacoustic tomography can be used to noninvasively visualize subcutaneous vascular networks. We applied this novel technology preoperatively in patients undergoing breast reconstruction to detect individual variations in the midline-crossing arteries.

METHODS

Six patients scheduled to undergo breast reconstruction using free deep inferior epigastric artery perforator flaps were examined. Each scan of the 12 × 8-cm region took approximately 8 min. The accuracy of the tentative artery evaluation defined by photoacoustic tomography was compared with the arterial phase detected by intraoperative indocyanine green angiography. The number of perforator vessels used for the flap, surgical time for flap elevation, and perfusion area ratio were compared with those of the control group.

RESULTS

The average match rate between tentative artery prediction by photoacoustic tomography and arterial-phase assessment by intraoperative angiography in five patients was 79.8%. Each midline-crossing artery showed individual variations. The photoacoustic tomography group (PAT-1 to 5) showed 1.8 perforators per flap, 163 min for flap elevation, and 93% perfusion area, with no significant differences from the control group (N = 5). A 63-year-old woman (PAT-6) with abdominal scars, including a midline abdominal incision, showed a preserved midline-crossing artery. The planned single perforator deep inferior epigastric perforator flap was successfully applied to the contralateral perfusion area.

CONCLUSIONS

Photoacoustic tomography noninvasively visualizes the subcutaneous midline-crossing arterial networks. Understanding individual vascular variations can support preoperative planning and surgical indication of abdominal flaps, especially in patients with postsurgical scars.

Effectiveness of the proximal medial branch in DIEP flaps for breast reconstruction using Hartrampf zone IV

BACKGROUND

When performing breast reconstruction using a deep inferior epigastric artery (DIEA) perforator (DIEP) flap, including Hartrampf zone IV, the bipedicled DIEP flap has been argued to be necessary to ensure stable perfusion. However, a proximal medial branch (PMB), which is the most proximal perforator of DIEA, may make it possible to obtain adequate perfusion in a unilateral DIEP flap. This study aimed to clarify the detailed anatomical characteristics of PMB and its potential clinical applications in breast reconstruction.

METHODS

This retrospective study was conducted on breast reconstruction using the DIEP flap between May 2020 and July 2023. Data on PMB anatomy were collected from preoperative contrast-enhanced computed tomography angiography, and contralateral perfusion of the flap was estimated using intraoperative indocyanine green angiography.

RESULTS

PMB was present in approximately 85% of the cases, arising near the lateral border of the rectus abdominis, branching caudomedially in more than half of the cases, and perforating 2.3 cm laterally and 8.8 cm caudally, on average, from the umbilicus. The average perfusion area of zones II and IV significantly expanded to 96.5% and 74.2%, respectively, when PMB was included in the DIEP flap, and 9 of 22 cases showed contrast extending to the entire zone IV.

CONCLUSIONS

The use of the DIEP flap with PMB is a good option for substantial-volume breast reconstruction. When utilizing PMB, it is important to consider its specific anatomy, location of the main perforator, and pedicle length.

Perfusion area versus volume of the DIEP flap: A multivariable analysis of perforator and flap characteristics for estimation of perfusion area and volume

BACKGROUND

The extent of perfusion of a deep inferior epigastric artery perforator (DIEP) flap is a primary concern for surgeons. This study aimed to determine whether the flap area or volume can be estimated using perforator and flap characteristics.

METHODS

Intraoperative flap perfusion was assessed using indocyanine green angiography in patients who underwent DIEP flap breast reconstruction between November 2018 and February 2023. The area perfused by a single dominant perforator was delineated on the surface of the flap and measured using the ImageJ software. Multiple linear regression analysis was conducted to estimate the 'perfusion ratio,' defined as the perfused area divided by the total flap area. Potential predictor variables included flap size (cm2), flap thickness (mm), perforator diameter (mm), perforator rows (medial/lateral), vertical location of perforator (at or above/below the umbilicus), and perforator eccentricity (vertical distance from upper flap margin to perforator, cm).

RESULTS

In total, 101 patients were included in this analysis. The mean 'perfusion ratio' was 67.8% ± 11.5%, predicted by perforator diameter (p = 0.022) and vertical location below umbilicus (p < 0.001) with positive correlations and negatively correlated with flap thickness (p = 0.003) in the multivariable analysis. Both perfusion area and weight were predicted by perforator diameter, vertical location of perforator, flap size, and flap thickness (p < 0.001). The coefficient of determination (adjusted R2) for prediction of perfusion weight was higher than that for the perfusion area (75.5% vs. 69.4%).

CONCLUSIONS

Flap volume, rather than area, is determined by a perforator of a given diameter and location.

Contemporary Microsurgical Breast Reconstruction: Abdominally Based Flaps

LEARNING OBJECTIVES

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

SUMMARY

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

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.

ACR Appropriateness Criteria® Imaging of Deep Inferior Epigastric Arteries for Surgical Planning (Breast Reconstruction Surgery): 2022 Update

Breast cancer is the most common malignancy in women in the United States, with surgical options including lumpectomy and mastectomy followed by breast reconstruction. Deep inferior epigastric perforator (DIEP) flap is a muscle-sparing perforator free flap breast reconstruction technique, which uses the deep inferior epigastric artery (DIEA) perforators to create a vascular pedicle. Multiple perforators are identified by preoperative imaging, which are typically ranked based on size, location, and intramuscular course. The goal of preoperative imaging is to aid the surgical team in preoperative planning given the variability of the DIEA perforator branches anatomy between patients. The objective of this document is to review the imaging modalities that can be used preoperatively to identify the optimal perforator and thereby reduce intraoperative complications, reduce postoperative complications, and improve clinical outcomes. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The Influence of Flow Velocity in the Feeding Vessel on Flap Perfusion in Deep Inferior Epigastric Artery Perforator Flap

Background Contralateral perfusion of zones II and IV is critical to estimate the amount of fat necrosis and determine intraoperative flap sacrifice during autologous breast reconstruction. We aimed to determine whether perfusion of the contralateral side was affected by the peak flow velocity in the feeding vessels in the deep inferior epigastric artery (DIEA) perforator free flap reconstructions.

Methods This was a retrospective review of patients who received DIEA perforator flap for autologous breast reconstruction from February to July 2020. Intraoperative indocyanine green (ICG) angiography and measurement software (Image J) were used to validate the perfusion of the contralateral side of the flap. Peak flow in the vessels was measured with duplex color Doppler and linear correlation was used to analyze the association between perfusion and blood flow velocity.

Results Forty-two patients received a DIEP flap. The average age of the patients was 48.5 years, and body mass index was 23.84 kg/m2. Peak flow velocity of the internal mammary artery (IMA) was significantly higher than that of the DIEA (p <0.05). Contralateral perfusion confirmed by ICG angiography was higher in the IMA than in the DIEA (p <0.05). A linear correlation was found between peak speed (p = 0.045) and ICG perfusion length (p = 0.00003).

Conclusion The status of flap perfusion depends on the feeding vessel. The velocity of blood flow between IMA and DIEA is different, and the flap perfusion varies accordingly. Therefore, ICG angiography should be performed after anastomosis at the recipient site for an accurate assessment.

Use of Indocyanine Green Angiography decreases the risk of complications in autologous- and implant-based breast reconstruction: A systematic review and meta-analysis

INTRODUCTION

Indocyanine Green Angiography (ICG-A) is an imaging technique used to visualize tissue perfusion in real time. The aim of this systematic review and meta-analysis is to evaluate all published papers on breast reconstruction using ICG-A, which provides information on complication rates and to investigate whether the use of this peroperative method decreases the risk of complications.

MATERIALS AND METHODS

MEDLINE/PubMed, EMBASE, Cochrane, and UpToDate were searched using relevant terms. The literature was assessed using the PRISMA guidelines. Inclusion criteria were: original articles written in English assessing ICG-angiography in breast reconstruction. The individual studies were evaluated according to Cochrane guidelines.

RESULTS

The search yielded 243 papers on ICG-A and breast reconstruction. Twenty-six of these were included for analysis. The risk of overall major complications ([OR] = 0.53, 95% confidence interval (CI) = 0.43-0.66, p = 0.00001) and overall loss of reconstruction ([OR] = 0.58, 95% CI = 0.37-0.92, and p = 0.020) was significantly lower when peroperative ICG-A was used. When using ICG-A to evaluate mastectomy flaps, a statistically lower risk of major complications ([OR] = 0.56 and p = 0.0001) and the loss of reconstruction was found ([OR] = 0.46, p = 0.006). ICG-A used in autologous breast reconstruction significantly reduced the risk of minor ([OR] = 0.62 and p = 0.001) and major complications ([OR] = 0.53 and p = 0.0028).

CONCLUSIONS

This is the first systematic review to analyze the use of ICG-A on both mastectomy flaps and autologous reconstruction. The results obtained in the current study indicate that the use of ICG-A in breast reconstructive procedures reduces the complications as well as the loss of reconstruction.

A Systematic Review and Meta-Analysis of Microvascular Stacked and Conjoined-Flap Breast Reconstruction

BACKGROUND

 Stacked and conjoined (SC) flaps are a useful means of increasing flap volume in autologous breast reconstruction. The majority of studies, however, have been limited to smaller, single-center series.

METHODS

 A systematic literature review was performed to identify outcomes-based studies on microvascular SC-flap breast reconstruction. Pooled rates of flap and operative characteristics were analyzed. Meta-analytic effect size estimates were calculated for reconstructive complication rates and outcomes of studies comparing SC flaps to non-SC flaps. Meta-regression analysis identified risk factors for flap complications.

RESULTS

 Twenty-six studies were included for analysis (21 case series, five retrospective cohort studies) for a total of 869 patients, 1,003 breasts, and 2006 flaps. The majority of flaps were harvested from the bilateral abdomen (78%, 782 breasts) followed by combined abdomen-thigh stacked flaps (22.2%, 128 breasts). About 51.1% of flaps were anastomosed to anterograde/retrograde internal mammary vessels (230 breasts) and 41.8% used internal mammary/intraflap anastomoses (188 breasts). Meta-analysis revealed a rate of any flap complication of 2.3% (95% confidence interval: 1.4-3.3%), Q-statistic value p = 0.012 (I ² = 43.3%). SC flaps had a decreased risk of fat necrosis compared with non-SC flaps (odds ratio = 0.126, p < 0.0001, I ² = 0.00%), though rates of any flap and donor-site complication were similar. Age, body mass index, flap weight, and flap donor site and recipient vessels were not associated with increased risk of any flap complication.

CONCLUSION

 A global appraisal of the current evidence demonstrated the safety of SC-flap breast reconstruction with low complication rates, regardless of donor site, and lower rates of fat necrosis compared with non-SC flaps.