Simplified profunda artery perforator (PAP) flap design using power Doppler ultrasonography (PDU): A prospective study

Evolution and Application of Ultrasound for Flap Planning in Upper Extremity Reconstruction

Accurate preoperative localization of dominant perforators provides crucial information about their location and diameter, leading to reduced surgical time, improved flap viability, and decreased complications. Ultrasound has increased in popularity in recent years, with the advantages of providing reproducible, accurate, cost-effective, and real-time information while reducing radiation exposure. Precise preoperative mapping of perforators allows for rapid and safe elevation of suprafascial, thin, and superthin flaps. This review focuses on the role of ultrasound as a tool for preoperative flap planning in the upper extremities.

One versus two vein anastomoses in breast reconstruction with a profunda artery perforator flap-does it make a difference

BACKGROUND

The profunda artery perforator (PAP) flap has gained popularity as a reliable alternative in breast reconstruction. Extensive research has focused on its vascular supply, dissection techniques, and broader applications beyond breast reconstruction. This study aims to investigate the correlation between the number of veins anastomosed for the PAP flap and postoperative complications.

METHODS

A retrospective study was conducted to evaluate the outcomes of breast reconstructions with PAP flaps at our institution between 2018 and 2022. A total of 103 PAP flaps in 88 patients were included. Statistical analysis was performed to compare outcomes between flaps with one vein anastomosis and those with two vein anastomoses. Patient characteristics, intra and postoperative parameters were analysed.

RESULTS

One vein anastomosis was used in 36 flaps (35.0%), whereas two vein anastomoses were used in 67 flaps (65.0%). No significant differences were found in patient characteristics between the one vein and two vein groups. The comparison of ischemia times between flaps with one versus two veins revealed no statistically significant difference, with mean ischemia times of 56.2 ± 36.8 min and 58.7 ± 33.0 min, respectively. Regarding outcomes, there were no statistically significant differences in secondary lipofilling, revision of vein anastomosis, or total flap loss between the two groups. Fat necrosis was observed in 5 (13.9%) one vein flaps and 5 (7.5%) two vein flaps, indicating no statistically significant difference between the two groups (p = .313). In the one vein group, the most frequently employed coupler ring had a diameter of 2.5 mm. In the two vein group, the most prevalent combination consisted of a 2.0 mm diameter with a 2.5 mm diameter.

CONCLUSION

Based on our study results, both one vein anastomosis and two vein anastomoses are viable options for breast reconstruction with PAP flap. The utilization of either one or two veins did not significantly affect ischemia time or flap loss. Fat necrosis exhibited a higher incidence in the single-vein group; however, this difference was also not statistically significant. These findings underscore the effectiveness of both approaches, providing surgeons with flexibility in tailoring their surgical techniques based on patient-specific considerations and anatomical factors.

Profunda Artery Perforator Flaps From the Posteromedial Region of the Thigh for Head and Neck Reconstruction

OBJECTIVE

Profunda femoris artery perforator flaps (PAPFs) have not been widely used in head and neck reconstructions. The feasibility and outcomes of PAPFs for various head and neck reconstructions need to be investigated.

STUDY DESIGN

Retrospective analysis.

SETTING

A single-institution review.

METHODS

PAPFs were utilized in head and neck reconstructions from 2019 to 2021. Local anatomy, surgical technique, and complications were discussed. Chimeric PAPF applications with muscle components were described for coverage of extensive multiunit defects. Additionally, aesthetic and functional outcomes were compared with anterolateral thigh perforator flaps.

RESULTS

A total of 33 cases were included. The average age was 54.2 years (range, 30-74). The most common underlying pathology was oral squamous cell carcinoma (n = 26, 78.8%), while the mean ± SD body mass index was 25.4 ± 2.8 kg/m² . Middle perforators (n = 14, 42.4%) were the most commonly utilized ones. The perforator-based chimeric/composite applications were used in 9 (27.3%), with the muscular components consisting of gracilis (n = 3, 9.1%), adductor magnus (n = 5, 15.2%), or semimembranosus muscles (n = 1, 3.0%). Venous thromboses of the PAPFs were found in 2 (6.1%), though salvaged. The occurrence of postoperative 90-day morbidity (complication) was related to mandibulectomy/maxillectomy (P = .020). Postoperative validated questionnaires showed a trend of intermediate to high scores, indicating noninferior outcomes in several categories, when compared with the anterolateral thigh perforator flap counterparts.

CONCLUSION

PAPFs are a good reconstructive alternative for intermediate to large head and neck reconstructions. Besides, PAPFs can provide sufficient tissue volume and versatility of potentially incorporating adjacent muscle components.

Comparison of surgical and patient-reported outcomes between 85 profunda artery perforator flaps and 122 deep inferior epigastric perforator flaps as first choice treatment for breast reconstruction

BACKGROUND

The profunda artery perforator (PAP) flap for breast reconstruction was first published in 2012. Since then, many centers implemented its application as second-line treatment for breast reconstruction in cases where patient characteristics make the deep inferior epigastric perforator (DIEP) flap not feasible to perform. In our center, we established the PAP flap as a first-line procedure for a multitude of reasons for a specific patient population. This study describes perioperative measure, clinical outcomes, and patient-reported outcome measures in comparison to the gold standard, the DIEP flap.

METHODS

In this study, we analyzed all PAP flaps and DIEP flaps performed in a single center between March 2018 and December 2020. We present patient characteristics, surgical technique, perioperative care, surgical outcomes, and complications. The Breast-Q was used to assess patient-reported outcome measures.

RESULTS

A total of 85 PAP flaps and 122 DIEP flaps were performed within 34 months. Average follow-up was 11.6 ± 5.8 months for the PAP group and 11.1 ± 5.8 months for the DIEP group (p = 0.621). Patients' average body mass index was higher in the DIEP flap recipients. Operation time was shorter and ambulation faster in PAP flap recipients. DIEP flap application resulted in higher Breast-Q scores.

CONCLUSIONS

While the PAP flap demonstrated favorable perioperative measures, outcome measures were better with the DIEP flap. The PAP flap is fairly new and demonstrates high potential while still showing a need for refinement compared to the DIEP flap.

The profunda artery perforator flap for upper limb reconstruction: A case report and literature review on the flap applications in reconstruction

The profunda femoris artery perforator (PAP) flap has been recently popularized as an alternative option for microsurgical reconstruction. The use of PAP flap has never been reported and described for reconstruction of the upper extremities, in particular the forearm. The purpose of this case report is to describe a case suggesting the PAP flap as a further reconstructive option in the upper limb. A 16-year-old girl who sustained a traumatic injury to her right dominant forearm resulting in subtotal circumferential tissue loss following a road traffic accident was referred to the authors' department 2 years post-trauma. The disabling fibrotic sequelae on her volar forearm (15 × 10 cm) resulted in a nonfunctional hand. She was unable to perform any active movement of her wrist or digits. Passive movements in the finger joints were preserved. Following debridement and reconstruction of nerves and tendons, soft tissues were resurfaced with a PAP flap. The transverse skin paddle, 12 × 7 cm, was placed distally with the adipofascial portion positioned proximally above the muscle bellies and anastomoses site. A small raw area (4 × 3 cm) was covered with an acellular dermal matrix (ADM). The postoperative course was uneventful. At 9 months postoperatively, the patient demonstrated active flexion and extension of the fingers with independent function. The patient reported satisfaction with the flap donor site and forearm resurfacing. The PAP flap can be a further option for areas requiring soft tissue coverage in patients refusing visible scars. This flap had both the advantage of reducing the morbidity and visibility of the donor site, as well as the ability to resurface a large recipient site with soft and pliable tissue, covering exposed nerves and tendons.

Technical Aspects of High-Resolution Color-Coded Duplex Sonography for the Design of Perforator Flaps

BACKGROUND

 Technical aspects are of utmost significance for an efficient execution in designing perforator flaps with high-resolution color-coded Duplex sonography (CCDS). The following study evaluates decisive factors for a successful microvessel examination conducted by the microsurgeon.

METHODS

 Technical knowledge presented in this study was based on a series of more than 200 perforator flaps planned with CCDS. Flap reconstructions were performed at the University Hospital Regensburg, Germany, from July 2013 to January 2021. Standard high-resolution ultrasound (US) devices with linear multifrequency transducers of 4 to 18 MHz were used. Modes and device settings were evaluated regarding applicability by microsurgeons. Key steps for safe perforator identification and further optional steps for additional assessment should be discriminated.

RESULTS

 Different US modes including brightness mode (B-mode), color flow (CF), power Doppler (PD), pulse wave (PW), and blood flow (B-Flow) were used. Transducers from 15 MHz and up were favorable to detect microvessels. Knobology of a standard US device regarding buttons, switches, and specific onscreen options with relevance for perforator mapping was subcategorized in four different groups. For qualitative and quantitative evaluation of microvessels, different US modes were tested with respect to their usefulness.Vital elements of the CCDS exam are disaggregated into three key steps for safe perforator identification and three optional steps for further perforator characterization. A standardized protocol for the CCDS exams was applied. Downregulation of pulse-repetition frequency/scale to adapt device sensitivity to slow-flow velocities represented the most important criterion to visualize microvessels.Qualitative microvessel evaluation was performed in B-mode, CCDS, PD mode, and B-Flow mode. Quantitative assessment was executed using PW-mode and CCDS measuring the microvessels' diameter (mm) and flow characteristics. Quantitative information may be obtained using PW-mode and the distance-measuring tool in CF-mode.

CONCLUSION

 Technical aspects with respect to proper device trimming and application decisively impact CCDS-guided perforator vessel identification and evaluation.

Investigation of flow velocity in recipient perforator artery for a reliable indicator for the flap transfer with perforator to perforator anastomosis

INTRODUCTION

In flap transfer with perforator to perforator anastomosis (FTPPA), encountering poor pulsation and blood flow in a recipient perforator intraoperatively often makes FTPPA impossible. This study sought to identify color and spectral Doppler ultrasonography (CSDUS) parameters that can aid reliable preoperative selection of a recipient perforator artery.

PATIENTS AND METHODS

The study enrolled 38 patients with lower extremity lymphedema who underwent vascularized lymphatic tissue transfer with perforator to perforator anastomosis for physiological lymphatic flow reconstruction. In all cases, three candidate recipient perforators were searched in each lower extremities, and vessel diameter and peak systolic flow velocity (PSFV) were measured. The inclusion criteria for candidates were a vessel diameter of >0.5 mm and a PSFV of >10 cm/s. These measures were compared with intraoperative findings, diameters and if there was pulsation and visible spurting evident.

RESULTS

A total of 114 candidates were selected, and 52 of the candidates were dissected until suitable perforators were found. PSFV (cm/s) on CSDUS was ≥20.0 in 32 perforators (84.2%) and was 15.0-19.9 in 6 perforators (15.8%) in the group with pulsation and visible spurting evident, and 15.0-19.9 in one perforator (7.1%) and ≤ 14.9 in 13 perforators (92.9%) in the group without pulsation and visible spurting evident. There was a statistically significant correlation between preoperative PSFV and intraoperative pulsation and visible spurting evident after dissection (P = 0.021 × 10^-3 ). The flap survival rate was 92.1%.

CONCLUSION

PSFV is an important preoperative determinant of the suitability of a recipient perforator artery for FTPPA.

Do-It-Yourself Preoperative High-Resolution Ultrasound-Guided Flap Design of the Superficial Circumflex Iliac Artery Perforator Flap (SCIP)

The superficial circumflex iliac artery perforator (SCIP) flap is a well-documented, thin, free tissue flap with a minimal donor site morbidity, and has the potential to become the new method for resurfacing moderate-size skin defects. The aim of this study is to describe an easy, reliable, systematic, and standardized approach for preoperative SCIP flap design and perforator characterization, using color-coded duplex sonography (CCDS). A list of customized settings and a straightforward algorithm are presented, which are easily applied by an operator with minimal experience. Specific settings for SCIP flap perforator evaluation were investigated and tested on 12 patients. Deep and superficial superficial circumflex iliac artery (SCIA) branches, along with their corresponding perforators and cutaneous veins, were marked individually with a permanent marker and the anatomy was verified intraoperatively. From this, a simplified procedure for preoperative flap design of the SCIP flap was developed. Branches could be localized and evaluated in all patients. A preoperative structured procedure for ultrasonically guided flap design of the SCIP flap is described. A 100% correlation between the number and emergence points of the branches detected by preoperative CCDS mapping and the intraoperative anatomy was found.

The Profunda Artery Perforator Flap: A Versatile Option for Head and Neck Reconstruction

BACKGROUND

Although the profunda artery perforator flap has gained popularity in breast reconstruction, it has not been well described for reconstruction of head and neck defects. The authors report their experience with free profunda artery perforator flaps in postoncologic head and neck reconstruction.

METHODS

A retrospective review of all free profunda artery perforator flaps used for head and neck reconstruction from 2016 to 2019 was performed.

RESULTS

Overall, 61 profunda artery perforator flap reconstructions were performed: 45 single independent flaps, 12 in conjunction with a second free flap, and four in combination with two other free flaps. The profunda artery perforator flaps were most commonly used for reconstruction of the tongue (n = 19), cheek (n = 11), parotid (n = 10), and maxilla (n = 6). The profunda artery perforator flaps averaged 7.1 × 12.1 × 1.9 cm, with a mean pedicle length of 11.5 cm. The A, B, and C perforators were located at mean distances of 7.4 cm (range, 4 to 11.5 cm), 11.7 cm (range, 8 to 18 cm), and 16.1 cm (range, 14 to 20.5 cm) from the pubic tubercle along the axis of the adductor longus muscle and 7.9 cm (range, 7 to 11cm), 7.6 cm (range, 7 to 15.5 cm), and 7.2 cm (range, 6 to 16 cm) posterior and perpendicular to the axis. There were three partial flap losses. Eight patients (13 percent) had recipient-site complications necessitating operative intervention: four for vascular compromise of the profunda artery perforator flap, two for hematoma evacuation, and two for infection. Donor-site complications were noted in seven patients (11 percent), two of whom required operative intervention.

CONCLUSIONS

The profunda artery perforator flap is a versatile and reliable flap with consistent anatomy and a low complication rate. The profunda artery perforator flap seems to be a reasonable alternative for reconstruction of head and neck defects.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Perforator Mapping of the Profunda Artery Perforator Flap: Anatomy and Clinical Experience

BACKGROUND

Discovering alternatives to workhorse flaps that have more consistent anatomy and lower donor-site morbidity has become a focus of reconstructive surgery research. This study provides a simplified approach to profunda artery perforator flap design and harvest based on reliable anatomical landmarks.

METHODS

A retrospective review was conducted of 70 patients who underwent 83 profunda artery perforator flap reconstructions for postoncologic defects from 2016 to 2018. The authors recorded and analyzed the profunda artery perforator flap sizes and clinical applications, the numbers and locations of the perforators, and the patient outcomes.

RESULTS

Most of the profunda artery perforator flaps were for head and neck [46 patients (65.7 percent)] and breast [21 patients (30 percent)] reconstructions. Flaps were most commonly based on perforator A (33.7 percent) and perforator B (33.7 percent), followed by perforators B and C combined (18.1 percent). Perforators were located a mean of 7.5 cm (perforator A), 12.7 cm (B), and 17.6 cm (C) distal to the pubic tubercle parallel to the axis between the pubic tubercle and the medial femoral condyle and 7.9 cm (A), 7.3 cm (B), and 6.1 cm (C) posterior from the axis. There was no flap loss. One patient underwent successful salvage surgery after arterial flap thrombosis. Eight patients (9.6 percent) developed superficial wound dehiscence that was managed conservatively.

CONCLUSIONS

Perforator mapping demonstrated consistent anatomical locations of sizeable profunda artery perforators in the inner thigh. Along with its consistent and robust vascular anatomy and minimal donor-site morbidity, the profunda artery perforator flap's volume and pliability make it a reliable option for soft-tissue reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Feasibility study of preoperative microvessel evaluation and characterization in perforator flaps using various modes of color-coded duplex sonography (CCDS)

BACKGROUND

Color-coded duplex sonography (CCDS) is useful for perforator flap design showing the highest sensitivity in identifying microvessels. This prospective study evaluates the feasibility of different ultrasound (US) modes applied by the microsurgeon in daily practice suggesting quantifiable reference values.

METHODS

Twenty-four patients aged between 17 and 68 years (mean 43.3 ± 14.2 years) with 18 anterolateral thigh (ALT) and 6 superficial circumflex iliac artery (SCIP) flaps were included. Indications were traumatic (n = 12), infectious (n = 6), ischemic (n = 4), or tumor-associated defects (n = 2). Different US modes were evaluated regarding applicability using multifrequency linear probes (5-15 MHz). Vessels diameter, peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were measured. Preoperative results were correlated to intraoperative findings.

RESULTS

In the examined patient group with 24 perforator flaps a 100% correlation was seen when comparing perforators detected with CCDS/PD with intraoperative findings using optimized US settings. Sensitivity, PPV, and accuracy of CCDS were 100% respectively. Mean PSV of 16.99 ± 6.07 cm/s, mean EDV of 5.01 ± 1.84 cm/s and RI of 0.7 ± 0.07 were measured in microvessels (PW-mode). CCDS proved to be superior compared to PD in correct diameter assessment showing a mean diameter of 1.65 ± 0.45 mm, compared to PD-mode 1.31 ± 0.24 mm. Mean PSV and EDV were higher in ALT than in SCIP flaps, RI was slightly higher in SCIP flaps (p > .05). There were no significant differences in size of different flaps' perforators (p > .05).

CONCLUSION

CCDS represents a highly valuable tool in the daily practice of free flap reconstructions using optimized low flow US settings and multifrequency linear probes.

Comparison between Different Perforator Imaging Modalities for the Anterolateral Thigh Perforator Flap Transfer: A Prospective Study

BACKGROUND

 Perforator imaging is routinely performed before perforator flap harvest. Hand-held Doppler (hhD) and color duplex ultrasonography (CDU) are currently the most popular radiation-free methods for this purpose that can be applied by the surgeon alone. The aim of this study was to compare the accuracy, reliability, and feasibility of hhD and CDU with indocyanine green angiography (ICGA) in the anterolateral thigh perforator flap (ALTPF).

METHODS

 All consecutive ALTPF procedures between May 2017 and April 2018 were included in this prospective study. The perforators were visualized by three investigators independently and randomized, applying hhD, CDU, and ICGA. The presence and the distance to the identified perforator were registered. Further, body mass index (BMI), American Society of Anesthesiologists-status, and the patient's history regarding smoking, alcohol use, and diabetes mellitus were registered alongside gender and age to analyze possible confounders.

RESULTS

 A total of 12 patients were enrolled with a median age of 67 (52-87) years. In total, 30 perforators were detected intraoperatively as well as with the ICGA. The latter visualized the perforators significantly more precisely than hhD and CDU (p < 0.001 and p = 0.001). The sensitivity and positive predictive value were 67 and 62% for hhD, 73 and 64% for CDU, and 100 and 100% for ICGA, respectively.

CONCLUSION

 According to this study, ICGA visualized perforators more accurately than the standard methods hhD and CDU. Further, it was associated with the highest sensitivity and positive predictive value. ICGA consistently delivered excellent results, whereas hhD and CDU showed variability.

High-Resolution Ultrasound-Guided Perforator Mapping and Characterization by the Microsurgeon in Lower Limb Reconstruction

BACKGROUND

 Preoperative ultrasound (US)-guided perforator mapping has immensely simplified perforator flap planning. It may be executed by the microsurgeon. Device settings and selection of ultrasound modes are of utmost significance for detection of low-flow microvessels. The following study evaluates different US modes.

METHODS

 A prospective complete data acquisition was performed from July 2018 to June 2019 in a subset of patients who underwent US-guided flap planning. Multifrequency linear transducers were used applying five US modes. Brightness (B)-mode, color flow (CF), power Doppler (PD), pulse wave (PW), and B-flow modes were evaluated regarding applicability by microsurgeons. Peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were chosen to evaluate flow characteristics. US results were correlated to intraoperative findings.

RESULTS

 A total number of eight patients (six males and two females) undergoing anterolateral thigh (ALT) or superficial circumflex iliac artery perforator (SCIP) flap surgery received an extensive standardized US-guided perforator characterization. Qualitative evaluation was performed in B-mode, color-coded duplex sonography (CCDS), PD, and B-flow mode. Quantitative assessment was executed using PW-mode and CCDS measuring the microvessels' diameter (mm) and flow characteristics (PSV, EDV, and RI). CCDS provided a mean diameter of 1.93 mm (range: 1.2-2.8 ± 0.51), a mean systolic peak of 16.9 cm/s (range: 9.9-33.4 ± 7.79), and mean RI of 0.71 (range: 0.55-0.87 ± 0.09) for lower limb perforators. All perforators located with US were verified by intraoperative findings. An optimized, time-effective US mapping algorithm was derived. Qualitative parameters may be evaluated with B-mode, CF, or B-flow. Smallest microvessels may be assessed in PD-mode. Lowering pulse-repetition frequency (PRF)/scale is mandatory to image low-flow microvessels as perforators. Quantitative information may be obtained using PW-mode and the distance-measuring tool in CF-mode. Image and video materials are provided.

CONCLUSION

 CCDS proved to be a powerful tool for preoperative perforator characterization when using a structured approach and mapping algorithm. Different techniques may be applied for specific visualizations and performed by the microsurgeon.

Step-by-step guide to ultrasound-based design of alt flaps by the microsurgeon - Basic and advanced applications and device settings

BACKGROUND

The anterolateral thigh (ALT) perforator flap is a popular reconstructive tissue transfer. Consistent with the "hot/cold zone" concept for rapid dissection and thin flap harvest, reliable preoperative perforator mapping is mandatory. Color-coded duplex sonography (CCDS) has been shown to have the highest pooled sensitivity and positive predictive value to identify ALT perforating vessels. By reviewing this guide, the reader should learn: 1. Probe selection and basic/advanced device settings 2. Interpreting tissue morphology 3. Structured mapping approach 4. Pedicle position planning 5. Safe flap design 6. Assess subcutaneous course and flap's thickness for subfascial/epifascial/suprafascial harvest 7. Implement perforators identified into a tailor-made flap design including chimeric flaps.

METHODS

Experiences with ultrasound-guided flap design gained from 125 ALT perforator flap free tissue transfers performed in two reconstructive centers was the basis of our guide. Our structured method comprises standardized markings, patient positioning, and simple ergonomics. Basic and advanced CCDS settings, selection, and conventional probe guidance are outlined for the microsurgeon.

RESULTS

Linear multifrequency probes (6-15 MHz) were used. Best preset programs were breast, thyroid, and vascular. Favorable device properties were depth focused to 2-5 cm, pulse repetition frequency (PRF/Scale) set low to 0.5-1.5 kHz/3-10 cm/s, color gain high, and wall filter (WF) low/off (< 50 Hz). Additional parameters were discussed. A 100% concordance rate was seen comparing preoperative perforator visualization with CCDS and intraoperative findings. Detailed picture and video material were demonstrated.

CONCLUSION

CCDS is a powerful tool for preoperative perforator mapping in perforator flaps such as the ALT.