Surgeon Reports

The role of SPY technology as a teaching tool in DIEP flap breast reconstruction

Deep inferior epigastric perforator (DIEP) flap breast reconstruction can be technically challenging and has a steep learning curve. This is in part due to the tedious and time consuming nature of perforator identification and dissection. Although complex, DIEP breast reconstruction has several advantages over other methods of breast reconstruction. By reconstructing the breast with the DIEP flap, the patient may experience little to no loss of muscle function, a decreased incidence of abdominal wall hernias, decreased pain, and a shortened hospital stay. Potential downsides to the DIEP flap include possible tenuous flap perfusion, venous or arterial occlusion, fat necrosis, and partial or complete flap loss. Given the reality of these possible complications it is necessary for the surgeon to determine if the perforators used to supply the flap will be sufficient to ensure maximal flap survival.

As new microsurgeons are trained and enter practice, the realities of the technical challenges with DIEP flaps become apparent. In order to realize the advantages to the donor site, one must make every effort to minimize overall flap complications. This requires ideal perforator identification, patency of the anastomosis, and adequate tissue perfusion. Additionally, if the flap can be designed as an SIEA (superficial inferior epigastric artery) flap, the abdominal wall can remain untouched. This eliminates the risk of hernia or bulge formation and can decrease overall pain and hospitalization time.

Every effort is made to train new surgeons in techniques which will achieve both robust flap perfusion and maintenance of donor site integrity. With this in mind, SPY technology has proven to be an invaluable tool when teaching new surgeons the techniques of perforator flap breast reconstruction. SPY technology gives the surgeon real time information on vessel patency and flap perfusion. Examples of the SPY’s utility in teaching these techniques include the ability to:

1. Help isolate perforators on the abdominal wall.
2. Assess tissue perfusion by the superficial inferior epigastric artery (SIEA) versus deep inferior epigastric perforators.
3. Assess patency of arterial and venous anastomoses after flap transfer.
4. Determine which areas of the flap should be discarded during flap insetting by valuating tissue perfusion. 

Isolating Perforators
Current techniques for pre-operative perforator isolation include hand-held Doppler assessment, pre-operative ultrasound and CT angiography. The advantage of the SPY over any of these modalities lies in its ability to provide information on real time blood flow. Additionally, SPY does not use potentially nephrotoxic dyes. Finally the SPY can be used in the operating room, therefore allowing the surgeon to scan areas they are particularly interested in.
After prepping the patient, the abdominal wall is scanned to identify perforators of the deep inferior epigastric artery. SPY pinpoints the location of these perforators and can identify which perforators have the greatest fluorescence intensity. Residents and fellows use this technology to assist with their dissection and to help choose which perforator to include with the flap.

SIEA vs. DIEP

Deciding to use the superficial versus deep systems in perforator breast reconstruction can often be difficult. While most surgeons would prefer to use the SIEA, it is not always available or doesn’t always perfuse an adequate amount of tissue. Modalities such as CT angiography, ultrasound and manual palpation of the SIEA are not always reliable methods of determining whether the SIEA is of adequate caliber or whether it will perfuse a sufficient amount of tissue. With SPY, this decision making process is simplified.

While elevating an abdominal flap, The SPY is used to scan the area of the inferior edge of the flap. The SIEA is located and its caliber is assessed. During the dissection the SIEA and one or two large perforators are isolated and preserved. The perforators and SIEA are then serially clamped and SPY is used to assess which system (superficial or deep) provides the best perfusion to the greatest amount of tissue.

Assessing Anastomotic Patency

Kinking of blood vessels, blood clots or improper suture placement can cause flap failure after microsurgery. Loss of a flap is a dreaded complication and every effort is made to ensure that blood flows in the newly joined vessels without interruption. SPY allows real-time visualization of the vessels and can confirm unobstructed flow. If the blood flow is compromised, the SPY can delineate the site of the problem so the surgeon can correct it.

Flap Perfusion

A successful DIEP breast reconstruction requires healthy and adequately perfused tissue. If marginally perfused tissue is included in the reconstruction, partial flap loss or fat necrosis can result. These complications often require further surgery and added cost to correct. SPY allows the surgeon to assess the boundaries of flap perfusion. The poorly vascularized tissue can be discarded and only healthy tissue is used to form the breast.

Conclusion

SPY is a valuable resource to the surgeon performing DIEP breast reconstruction as well as to the novice surgeon learning the techniques. It has the potential to reduce operative time and maximize flap survival. When used as a teaching tool, the SPY has the potential to minimize errors and bolster surgeon confidence.

- Dr. Jayant Agarwal, M.D.

Jay Agarwal, MD, is an assistant professor in the Department of Surgery Division of Plastic Surgery at the University of Utah School of Medicine and a Huntsman Cancer Institute investigator.

His clinical interests include aesthetic plastic surgery, hand surgery, and reconstructive microsurgery with a focus on reconstruction of traumatic injuries and defects caused by cancer. He emphasizes using perforator flaps, a cutting-edge technique that uses the patient’s own tissues to reconstruct the breast, head and neck, and extremities.

Dr. Agarwal graduated from medical school at Case Western Reserve University in Cleveland, Ohio, and completed combined residency training in general surgery and plastic surgery at the University of Chicago. After six years in Chicago, he went on to specialize in hand surgery and microvascular surgery at the Buncke Clinic in San Francisco.