Power Doppler imaging in preoperative planning and postoperative monitoring of muscle flaps

Preoperative color Doppler assessment in planning of gluteal perforator flaps

Gluteal artery perforator flaps have gained popularity due to reliability, preservation of the muscle, versatility in flap design without restricting other flap options, and low donor-site morbidity in ambulatory patients and possibility of enabling future reconstruction in paraplegic patients. But the inconstant anatomy of the vascular plexus around the gluteal muscle makes it hard to predict how many perforators are present, what their volume of blood flow and size are, where they exit the overlying fascia, and what their course through the muscle will be. Without any prior investigations, the reconstructive surgeon could be surprised intraoperatively by previous surgical damage, scar formation, or anatomic variants.For these reasons, to confirm the presence and the location of gluteal perforators preoperatively we have used color Doppler ultrasonography. With the help of the color Doppler ultrasonography 26 patients, 21 men and 5 women, were operated between the years 2002 and 2007. The mean age of patients was 47.7 (age range: 7-77 years). All perforator vessels were marked preoperatively around the defect locations. The perforator based flap that will allow primary closure of the donor site and the defect without tension was planned choosing the perforator that showed the largest flow in color Doppler ultrasonography proximally. Perforators were found in the sites identified with color Doppler ultrasonography in all other flaps. In our study, 94.4% flap viability was ensured in 36 perforator-based gluteal area flaps. Mean flap elevation time was 31.9 minutes. We found that locating the perforators preoperatively helps to shorten the operation time without compromising a reliable viability of the perforator flaps, thus enabling the surgeon easier treatment of pressure sores.

Preoperative MR Angiography in Free Fibula Flap Transfer for Head and Neck Cancer: Clinical Application and Influence on Surgical Decision Making

OBJECTIVE

We review the fibular free flap surgical procedure to illustrate the usefulness of preoperative lower limb MR angiography and to show how calf vascular anatomy on MR angiography affects patient surgical management.

CONCLUSION

With its high positive predictive value and sensitivity, preoperative MR angiography can improve the chances of a successful outcome at the recipient mandibular site. It provides the reconstructive surgeon with a road map, revealing vascular anomalies or disease that could alter or contraindicate surgery.

Ultrasonographic and color-flow Doppler ultrasonographic assessment of direct cutaneous arteries used for axial pattern skin flaps in dogs

OBJECTIVE

To describe a method for ultrasonographic and color-flow Doppler ultrasonographic imaging of the 4 direct cutaneous arteries commonly used for axial pattern skin flaps in dogs.

DESIGN

Descriptive report.

ANIMALS

20 clinically normal dogs.

PROCEDURES

Dogs were manually restrained and fundamental and harmonic ultrasonographic and color-flow Doppler ultrasonographic examinations of the superficial cervical, thoracodorsal, deep circumflex iliac (cranial and caudal branches), and caudal superficial epigastric arteries were performed by a resident in diagnostic imaging. The level of confidence in locating these vessels was subjectively graded as high, moderate, or low.

RESULTS

High-frequency fundamental and harmonic ultrasonography was important for maximizing image resolution, and color-flow Doppler ultrasonography was important for vessel identification. The superficial cervical artery was the most difficult vessel to identify; confidence in correct vessel identification was low or moderate. The thoracodorsal and deep circumflex iliac arteries were identified with a moderate or high level of confidence. The caudal superficial epigastric artery was the easiest vessel to identify; confidence in correct vessel identification was high. Except for the superficial cervical artery, the level of confidence in correct vessel identification improved over time as operator experience increased.

CONCLUSION AND CLINICAL RELEVANCE

Results suggest that the combination of fundamental ultrasonographic and color-flow Doppler ultrasonographic imaging is an easy and noninvasive method for identifying the 4 direct cutaneous arteries commonly used for axial pattern skin flaps in dogs. This method could be useful in planning axial pattern skin flaps, particularly in dogs with regional soft tissue trauma in which the integrity of the vessel is in question.

Preoperative Color Doppler Assessment in Planning of Anterolateral Thigh Flaps

The anterolateral thigh flap has many advantages, but it has not yet achieved widespread use because the perforators exhibit considerable anatomical variation and their locations are difficult to predict preoperatively. The authors performed a prospective study to investigate whether acoustic Doppler flowmetry and color Doppler ultrasonography were helpful for preoperative localization of the perforators in anterolateral thigh flaps. Ten patients scheduled for anterolateral thigh flap surgery were examined preoperatively with both acoustic Doppler flowmetry and color Doppler ultrasonography, and all points where the perforators seemed to penetrate the fascia lata were mapped. The actual perforating points were identified intraoperatively and were compared with the preoperatively mapped points. Fifteen perforators were detected in 10 patients. The concordance rate with acoustic Doppler flowmetry was 40 percent (95 percent confidence interval, 15 to 68 percent; p = 0.05). In contrast, the concordance rate with color Doppler ultrasonography was 100 percent (95 percent confidence interval, 81 to 100 percent; p = 0.05). Color Doppler examination was significantly more accurate than acoustic Doppler examination (determined by the binomial test; p < 0.0014). Three-dimensional anatomical information around the perforators was further useful in elevating flaps. The authors conclude that color Doppler examination can accurately identify the perforators and is useful for planning in anterolateral thigh flap surgery, whereas acoustic Doppler examination is unreliable.

Simultaneous use of bilateral caudal superficial epigastric axial pattern flaps for wound closure in a dog

A neutered male German shorthaired pointer sustained severe bite wounds to the left caudal flank and thigh area. Thorough wound lavage and debridement was performed immediately and also three days after presentation. Daily wound dressing resulted in the production of a mature granulation tissue bed. Prior to wound closure, colour flow Doppler ultrasonography was used to confirm blood flow through the right and left caudal superficial epigastric arteries and veins. Sixteen days after presentation, right and left caudal superficial epigastric axial pattern flaps were simultaneously elevated to cover the defect. The right flap was elevated as an island flap, rotated 120 degrees and used to cover the caudodorsal aspect of the defect. The left flap was elevated and rotated dorsally to cover the cranioventral aspect of the defect. Ninety per cent wound coverage was achieved and flap survival was total. The donor site defect was closed primarily and no dehiscence occurred. Three months postsurgery, the entire defect was closed and limb function was normal.

Color Doppler sonography in monitoring after free jejunum transplantation

The authors assessed the usefulness of color Doppler imaging in the monitoring of vascular circulation after free jejunum transplantation. Seven male patients were examined daily with color Doppler sonography for the first postoperative week between 1999 and 2000. All sonographic examinations were performed with an SSD5500 ultrasound scanner. Arterial and venous signals were documented reliably in all patients. The flashing red spots around the serosal wall revealed the patency of the anastomosed artery and vein. No failures of the graft occurred. The presence of the color Doppler signals was considered sufficient to define vascular patency. The real-time monographic (B-mode) examination revealed the thickness and the plicae circulares of the jejunum wall. These monographic (B-mode) images supported the viability of the transplanted jejuna. The authors found color Doppler sonography to be a reliable and effective form of monitoring after free jejunum transplantation.