Venous perforators in DIEAP flaps: An observational anatomical study using duplex ultrasonography

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Current Applications of Ultrasound Imaging in the Preoperative Planning of DIEP Flaps

Background The deep inferior epigastric artery perforator (DIEP) flap has become the gold standard for autologous breast reconstruction at many institutions. Although the deep inferior epigastric artery displays significant anatomic variability in its intramuscular course, branching pattern and location of perforating vessels, the ability to preoperatively visualize and map relevant vascular anatomy has increased the efficiency, safety and reliability of the DIEP flap. While computed tomography angiography (CTA) is often cited as the preoperative imaging modality of choice for perforator flaps, more recent advances in ultrasound technology have made it an increasingly attractive alternative.

Methods An extensive literature review was performed to identify the most common applications of ultrasound technology in the preoperative planning of DIEP flaps.

Results This review demonstrated that multiple potential uses for ultrasound technology in DIEP flap reconstruction including preoperative perforator mapping, evaluation of the superficial inferior epigastric system and as a potential adjunct in flap delay procedures. Available studies suggest that ultrasound compares favorably to other widely-used imaging modalities for these indications.

Conclusion This article presents an in-depth review of the current applications of ultrasound in the preoperative planning of DIEP flaps and explores some potential areas for future investigation.

The Role of Supermicrosurgery and Arborization Capture in Improving Free-styled Propeller Flap Survival

Background:

Propeller flaps have a higher-than-normal incidence of partial flap necrosis. Although venous supercharging has been shown to reduce this risk, its application is limited outside the scope of lower limb propeller flaps. In this article, we look at the ability of arborization capture and supermicrosurgery to allow propeller flaps to capture adjacent perforasomes and significantly improve flap survival.

Methods:

In a retrospective case series across two institutions, the outcomes of two groups of patients who had propeller flaps were compared. Group A patients were those who had conventional free-styled propeller flaps (n = 25), whereas Group B (n = 19) patients had propeller flaps algorithmically selected for either (1) arborization capture or (2) venous supercharging, or both. Two-way ANOVA analysis was performed to evaluate inter-group differences.

Results:

Conventional propeller flaps had a 64% complete survival rate (32% partial necrosis rate and a 4% total necrosis rate) compared with a 94% complete survival rate in modified propeller flaps. Of the 12 cases of arborization capture (perforator complex diameters of 1–2 mm), only one flap sustained partial flap loss, whereas all seven supercharged propeller flaps (selected for perforator diameter <1 mm, with venous supercharging, in addition to arborization capture) survived completely.

Conclusions:

The arborization technique should be the mainstay technique for all propeller flaps with perforator complex diameters of less than 2 mm while supercharging further enhances its survival, particularly in perforator complex diameters of less than 1 mm.

Comparison of Various Modalities Utilized for Preoperative Planning in Microsurgical Reconstructive Surgery

BACKGROUND

 The benefits of preoperative perforator imaging for microsurgical reconstruction have been well established in the literature.

METHODS

 An extensive literature review was performed to determine the most commonly used modalities, and their applicability, advantages and disadvantages.

RESULTS

 The review demonstrated varioius findings including decreases in operative time and cost with the use of CT angiography to identification of perforators for inclusion in flap design with hand-held Doppler ultrasound. Modalities like MR angiography offer alternatives for patients with contrast allergies or renal dysfunction while maintaining a high level of clarity and fidelity. Although the use of conventional angiography has decreased due to the availability of less invasive alternatives, it continues to serve a role in the preoperative evaluation of patients for lower extremity reconstruction. Duplex ultrasonography has been of great interest recently as an inexpensive, risk free, and extraordinarily accurate diagnostic tool. Emerging technologies such as indocyanine green fluorescence angiography and dynamic infrared thermography provide real-time information about tissue vascularity and perfusion without requiring radiation exposure.

CONCLUSION

 This article presents an in-depth review of the various imaging modalities available to reconstructive surgeons and includes hand held Doppler ultrasound, CT angiography, MR angiography, conventional angiography, duplex ultrasonography, Indocyanine Green Fluorescence Angiography and Dynamic Infrared Thermography.

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.

Ultrasound and Plastic Surgery: Clinical Applications of the Newest Technology

BACKGROUND

Color Doppler ultrasound (CDUS) has not been routinely used in plastic and reconstructive surgery. Barriers to use have included large, cumbersome equipment, low-definition images, cost, and availability. In addition, programs in plastic surgery have not included training with ultrasound (US); thus, many current-day practitioners are unfamiliar with and reluctant to use this technology. Nevertheless, recent studies have demonstrated the utility of US in surgical planning. With the miniaturization, clearer imaging, and decreased costs of the latest US technology, previous barriers to use have largely been eliminated.

METHODS

Fifty-six patients scheduled for either reconstructive or aesthetic surgery were evaluated preoperatively and/or intraoperatively by a single surgeon with the linear 12-4 probe of a Philips Lumify CDUS device (Philips, Reedsville, Penn). For patients undergoing flap reconstruction, potential donor sites were imaged in order to locate the largest perforator. For patients undergoing abdominal procedures, intraoperative visualization of the abdominal muscular layers was used for the delivery of anesthesia during transversus abdominis plane block. Lastly, the superficial fascial system (SFS) was subjectively evaluated in all preoperative patients.

RESULTS

For flap reconstruction, 11 patients were preoperatively examined with CDUS in order to locate the largest perforators prior to perforator flap reconstruction. Flaps studied included the deep inferior epigastric perforator, anterolateral thigh, tensor fascia lata, thoracodorsal artery perforator, superior gluteal artery perforator, and the gracilis musculocutaneous. Color Doppler ultrasound findings were confirmed intraoperatively for all cases (100%). In 2 (18.2%) of 11 cases, CDUS identified perforators not detected by computed tomography angiography. Twenty-five patients undergoing either abdominoplasty or deep inferior epigastric perforator flap reconstruction had successful intraoperative visualization of the abdominal wall muscular layers, thus allowing administration of transversus abdominis plane blocks by the operating surgeon. Twenty patients undergoing body contouring surgery had preoperative visualization of the SFS. The SFS was found to be varied not only among different patients but also within individual patients.

CONCLUSIONS

The newest, miniaturized CDUS technology has a variety of applications that may improve patient outcomes and experience in plastic surgery. Our observations require further investigation to quantify the perceived benefits of this new technology.

Concordance between preoperative computed tomography angiographic mapping and intraoperative perforator selection for deep inferior epigastric artery perforator flap breast reconstructions

Background

Preoperative imaging for perforator identification prior to a deep inferior epigastric artery perforator (DIEP) flap elevation for breast reconstruction has many advantages. Currently, computed tomography (CT) angiography provides good visualization of the perforators and their course, and is thus the imaging technique of choice. The primary aim of this study was to determine the concordance between the perforators identified preoperatively and the perforators ultimately selected intraoperatively, with a standardized protocol, in a single institution. Secondly, we wanted to compare our results with those of other, similar studies and, thirdly, to identify those factors that may lead to a higher concordance.

Methods

A retrospective review was undertaken of a case series of 49 consecutive patients undergoing unilateral autologous breast reconstruction with a DIEP flap at the Gelre Hospital, in the Netherlands, over a 4-year period from 2013 to 2017. The preoperative identification and selection of perforator number and location with the aid of CT angiography scanning were compared to the intraoperative findings and preference.

Results

Our study revealed a concordance of 67.3% between one or more perforators advised preoperatively by the radiologist and chosen intraoperatively by the surgeon. We identified significant differences in our protocol compared to others.

Conclusions

The study confirmed the benefit to both the patient and the surgeon when preoperative CT angiography is used. Scanning protocols may vary considerably and should thus be carefully scrutinized before future comparisons are made. Based on this study, the scanning range, method of selecting perforators and timing of image acquisition may have to be optimized for future prospective clinical trials.

Techniques and Perforator Selection in Single, Dominant DIEP Flap Breast Reconstruction: Algorithmic Approach to Maximize Efficiency and Safety

BACKGROUND

Perforator selection is critical to deep inferior epigastric perforator (DIEP) flap harvest. Commitment to a single perforator has the potential benefit of a simpler dissection, but may increase fat necrosis or perfusion-related complications compared with multiple perforator harvest.

METHODS

A 3-year retrospective study was carried out of all patients who underwent DIEP flap breast reconstruction performed by the senior author (M.S.-C). Data were collected on patient demographics and surgical outcomes.

RESULTS

One hundred eighty-three flaps were performed (105 patients) over 3 years. One hundred fifty-six bilateral (78 patients) and 24 unilateral flaps were included in the final study. Mean age was 47.8 ± 8.4 years and mean body mass index was 29.1 ± 5.3 kg/m. Seventy-five percent of flaps were based on single dominant perforators. Single perforators were used in 33.3 percent of flaps weighing over 1000 g, 80 and 74 percent of flaps weighing 500 to 1000 g and less than 500 g, respectively (p = 0.01). There were no differences in overall complications between single- versus multiple-perforator DIEP flaps. Neither body mass index nor flap weight posed additional risk to overall complications. Conversion to a muscle-sparing flap was 9.4 percent.

CONCLUSIONS

The authors present an algorithm for perforator selection, stepwise approach to flap harvest, and considerations for intraoperative decision-making in DIEP flap reconstruction. Single-dominant perforator flaps can be safely performed, but inclusion of the largest perforator is critical to flap perfusion. Additional perforators must be weighed against the associated tradeoff with donor-site morbidity. The threshold for conversion to a muscle-sparing flap is reduced with increased clinical experience.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Complete DIEP flap survival following pedicle resection, 4 years after its transfer. Clinical evidence of autonomization

We report a case of complete DIEP flap survival, following venous congestion due to the excision of a local recurrence with main pedicle, 4 years after its transfer for breast reconstruction.

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.

Quantifying Blood Flow in the DIEP Flap: An Ultrasonographic Study

Supplemental Digital Content is available in the text.

Background:

The maximum weight of tissue that a single perforator can perfuse remains an important question in reconstructive microsurgery. An empirically based equation, known as the flap viability index (FVI), has been established to determine what weight of tissue will survive on one or more perforators. The equation is FVI = Sum d(n)^4/W, where d is the internal diameter of each perforator and W is the final weight of the flap. It has been shown that if FVI exceeds 10, total flap survival is likely, but if under 10, partial flap necrosis is probable. The aim of this study was to measure absolute flow rates in deep inferior epigastric perforator (DIEP) flap pedicles and assess correlation with the determinants of the FVI, perforator diameter and flap weight.

Methods:

Color Doppler ultrasound was used to quantify arterial flow in 10 consecutive DIEP flap pedicles 24 hours after anastomosis.

Results:

In single-perforator DIEP flaps, flow rate was highly correlated with perforator diameter (r = 0.82, P = 0.01). Mean arterial flow rate was significantly reduced in DIEP flaps with 2 or more perforators (6 vs 38 cm³/min; P < 0.05).

Conclusions:

This study confirms that perforator size is a critical factor in optimizing blood flow in perforator-based free tissue transfer. Further research is required to understand the flow dynamics of perforator flaps based on multiple perforators. However, surgeons should be cognizant that a single large perforator may have substantially higher flow rates than multiple small perforators. Routine FVI calculation is recommended to ensure complete flap survival.

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.

Safety of salvaging impending flap congestion in breast reconstruction by venous supercharging of the cephalic vein

Autologous flap breast reconstruction is an established technique that carries a risk of vascular failure. We evaluated the safety of salvaging impending venous congestion by using the cephalic vein for supercharging autologous abdominal flaps. Our main outcome measures were flap survival, triggering or impairing lymphedema as measured by the physician or reported by the patient, and scar severity as measured by the Vancouver scar scale. We were able to save 100% of the flaps, but could not find any statistical association with or without increased lymphedema before and after the procedure. One patient reported that lymphedema worsened. The patients accepted the scars (mean Vancouver scar scale score, 5.7). In sum, using the cephalic vein to improve venous drainage of autologous breast reconstruction was safe and did not trigger or impair lymphedema, but scarring in the upper arm was unavoidable.