FLAP PEDICLE VENA COMITANT AS A VEINGRAFT DONOR SOURCE

DANIEL STEWART, M.D., F.A.C.S.,* JAMES LIAU, M.D., and HENRY VASCONEZ, M.D., F.A.C.S., F.A.C.P.

A vena comitant segment harvested from a flap’s pedicle can be used as an interpositional vein graft in selected microvascular cases.When a vascular pedicle includes paired venae comitantes, one of these can prove suitable for use as a vein graft while still allowing forvenous outflow of the flap. An additional operative site and procedure to harvest a vein graft can be avoided if a vena comitant segmentcan be used. We present eight cases in which pedicle vena comitant segments were used as interpositional vein grafts. In six cases, venacomitant grafts were used to supercharge or augment venous outflow in transverse rectus abdominis myocutaneous (TRAM) flaps usedfor breast reconstruction. A vena comitant graft was used to revise the venous anastomosis in one deep inferior epigastric perforator(DIEP) flap. The arterial anastomosis was revised with a vena comitant graft in a gracilis muscle free flap. Our experience demonstratesthe viability and utility of using the flap pedicle’s vena comitant as a source of vein graft in selected cases. VVC 2008 Wiley-Liss, Inc. Micro-surgery 29:115–118, 2009.

Using a vena comitant segment harvested from within a

flap’s pedicle as an interpositional vein graft could obvi-

ate the drawbacks of harvesting vein grafts from other

sites in selected microvascular cases. An additional oper-

ative site could be avoided and operative time could

potentially be decreased. Vessel size match could be opti-

mized with the use of a vena comitant graft with a cali-

ber similar to the pedicle artery or remaining vena comi-

tant. However, a pedicle vena comitant segment could

only be used as an interpositional graft if venous outflow

of the flap is assured through the remaining intact vena

comitant or an additional pedicle. We present eight cases

in which pedicle vena comitant segments were used as

interpositional vein grafts.

MATERIALS AND METHODS

Eight patients undergoing procedures requiring micro-

vascular anastomoses required the use of interpositional

vein grafts which were harvested from of one of the two

venae comitantes found within the vascular pedicles of

the flaps. Seven patients were females with age ranging

from 32 to 54 years, with a mean age of 43 years. Six of

these patients underwent breast reconstruction using ei-

ther arterial supercharged or venous outflow augmented

transverse rectus abdominis myocutaneous (TRAM) flaps.

One patient underwent breast reconstruction using a deep

inferior epigastric perforator (DIEP) flap. The single 44-

year-old male patient in this series required coverage of a

lower extremity wound using a gracilis muscle free flap.

In the six patients undergoing TRAM flap breast

reconstruction, flaps were based on single rectus abdomi-

nis muscle pedicles, but the ipsilateral deep inferior epi-

gastric vessels were left long to be used to supercharge

the flaps as needed. Paired venae comitantes were noted

in all six of the inferior epigastric pedicles. In four

patients there was concern regarding the arterial perfusion

of the flaps based on the appearance of the skin paddle

or the perfusion of the distal rectus muscle and filling of

the deep inferior epigastric pedicle (Fig. 1). A segment of

the larger of the two venae comitantes with extension to

include the proximal common vena comitant was har-

vested and used as an interpositional vein graft between

the inferior epigastric artery and the thoracodorsal artery

to arterially supercharge the TRAM flaps (Fig. 2). No

additional venous anastomosis was planned or attempted.

In two patients, the TRAM flaps were noted to have ve-

nous congestion based on the appearance of the flaps and

the engorgement of the inferior epigastric pedicle venae

comitantes. In these patients, one of the pedicle venae co-

mitantes was used as an interpositional vein graft

between the remaining vena comitant and the thoracodor-

sal vein to provide additional flap venous outflow.

One patient underwent right breast reconstruction

using a DIEP flap. Recipient vessels were the right inter-

nal mammary artery and vein. A single venous anastomo-

sis was performed using one of the inferior epigastric

venae comitantes. Although anastomoses were patent at

the completion of the procedure, the flap was noted to

become swollen and congested early in the postoperative

period (Fig. 3). She was returned emergently to the oper-

ating room for evacuation of a hematoma and exploration

of the pedicle. The venous anastomosis was found to be

thrombosed and under stretch as the inferior epigastric

vena comitant coursed over the inferior epigastric artery

and the arterial anastomosis. Thrombectomy and injection

of a thrombolytic agent were successful in restoring ve-

nous outflow from the flap, but a short vein graft was

needed to revise the venous anastomosis without the ten-

sion. Although the unused vena comitant was noted to be

Division of Plastic Surgery, University of Kentucky, Lexington, KY

*Correspondence to: Daniel Stewart, M.D., F.A.C.S, Kentucky Clinics E-101,740 South Limestone, Lexington, KY 40536-0284.E-mail: dstew3@email.uky.edu

Received 6 July 2008; Accepted 17 September 2008

Published online 22 October 2008 in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/micr.20589

VVC 2008 Wiley-Liss, Inc.

distended with a clot, a segment of this vein was har-

vested and the clot was extracted. After irrigating with

heparinized saline, it was used as an interpositional graft

between the initially used inferior epigastric vena comi-

tant and the internal mammary vein (Fig. 4).

A gracilis free flap was used for coverage of an

exposed calcaneal fracture and Achilles tendon with the

posterior tibial artery and vein used as recipient vessels.

An end-to-side arterial anastomosis was made difficult

because of thickened media of the posterior tibial artery

and small caliber of the flap pedicle’s artery. However, a

patent arterial anastomosis was established and a single

venous anastomosis was completed. The arterial anasto-

mosis was then noted to have thrombosed with platelet

aggregation. Several attempts at revision were unsuccess-

ful and resulted in loss of length of the flap’s artery. The

unused vena comitant in the gracilis muscle pedicle was

noted to be of adequate caliber and was harvested for use

as an interpositional vein graft. Good size match with the

artery allowed for end-to-end anastomosis with the flap’s

artery and an end-to-side anastomosis was completed

with posterior tibial artery.

Patency of all anastomoses and the vena comitant

vein grafts were confirmed at the completion of each pro-

cedure based on visible and palpable pulsation, gentle

strip tests, and examination using a hand-held Doppler

ultrasound. Clinical and hand-held Doppler ultrasound

Figure 1. A flaccid deep inferior epigastric artery with poor back-

flow caused concern for the adequacy of arterial inflow via the

superior deep epigastric artery within the rectus muscle pedicle of

this TRAM flap for breast reconstruction. The distended common

vena comitant was a good size match with the inferior epigastric

artery.

Figure 2. The vena comitant provided 8 cm of vein graft to bridge

the inferior epigastric and thoracodorsal arteries and allowed for an

arterial-only supercharged TRAM flap.

Figure 3. The DIEP flap threatened with a hematoma and venous

congestion secondary to thrombosis of the venous anastomosis.

Figure 4. The thrombosed venous anastomosis was revised with

an interpositional vein graft harvested from the unused vena comi-

tant (arrows A and B mark the vein graft anastomosis, while arrow

C marks the harvested stump) to relieve stretch as the vein crosses

over the inferior epigastric artery. Venous congestion was promptly

relieved and the flap went on to heal uneventfully.

116 Stewart et al.

Microsurgery DOI 10.1002/micr

examinations were used to monitor the flaps in the post-

operative period.

RESULTS

Two venae comitantes were found within each

TRAM flap and the DIEP flap inferior epigastric artery

pedicle. These usually joined into a common vena comi-

tant for a variable distance proximal to their origins with

the external iliac vein. Two venae comitantes were also

found in the pedicle of the gracilis muscle flap. Diameter

measurements were not made, but a vena comitant of

suitable caliber for use as an interpositional vein graft for

arterial or venous reconstruction was found in each pedi-

cle. Needed vein graft lengths varied and were not rou-

tinely measured, but an 8-cm-long segment of vena comi-

tant was harvested from one inferior epigastric pedicle.

Patency of the vena comitant grafts was confirmed

intraoperatively but was not specifically confirmed post-

operatively in the four supercharged and two venous

augmented TRAM flaps. Doppler ultrasound was used to

monitor the flaps along with clinical examination. As

long as the skin paddles appeared clinically viable with

examinations that included audible Doppler signals, long-

term patency of the vena comitant grafts was not critical.

However, in the venous congested TRAM flaps, disten-

tion in the remaining vena comitant resolved and venous

congestion of the flaps resolved without recurrence on

completion of the anastomoses using vena comitant

grafts.

Patency of the vena comitant grafts was essential for

flap survival in the DIEP flap breast reconstruction

patient and the patient requiring gracilis muscle free flap

coverage of the exposed calcaneal fracture. These flaps

were monitored with frequent clinical examinations,

including Doppler ultrasound. Flap survival was the ulti-

mate proof of graft patency in these two cases.

Two complications occurred in two of the eight

patients following the use of vena comitant grafts. Each

of these patients underwent supercharged TRAM flap

breast reconstruction. One patient developed an axillary

hematoma which did not require operative treatment. Sig-

nificant tissue loss occurred in a portion of zone II in

another moderately obese patient who had a lower mid-

line abdominal incision beginning about 4 cm below the

umbilicus. However, this was a not a complication that

supercharging could prevent. Instead of supercharging the

single rectus muscle pedicle, flap design should have

included a second pedicle to perfuse the flap contralateral

to the scar.

DISCUSSION

Vein grafts have been harvested from various sources

for use in microvascular surgery. An unreplantable finger

used for spare parts may provide artery or vein segments

for use as grafts.1 Veins found at the margins of a flap

have been used as well.1 However, an additional opera-

tive site, removed from either the flap donor or recipient

sites, is usually necessary.2 Harvesting a vein graft from

a separate operative site can potentially prolong the oper-

ative time. Potential for vessel mismatch remains despite

careful choice of the vein to be harvested. Commonly

used vein graft donors include the greater and lesser

saphenous, cephalic, and external jugular veins. Common

donor sites for harvesting smaller veins are the wrist,

volar forearm, and dorsal foot.1,3,4

We have confirmed only two other reports of the use

of a vena comitant as a vein graft source. An ulnar artery

vena comitant as a vein graft source for thumb replanta-

tion has been reported previously.5 Hallock reported the

use of flap pedicle vena comitant grafts in two cases of

free-tissue transfer.6 Our series further validates flap pedi-

cle venae comitantes as a potential vein graft donor site.

Our interest in the use of venae comitantes as a

potential vein graft donor source began with their use in

TRAM flaps for breast reconstruction which were super-

charged only on the arterial side with the deep inferior

artery. As no additional venous outflow was planned, the

venae comitantes were felt to be expendable and were

conveniently available for use as vein grafts. These first

four cases demonstrated the utility of the deep inferior

epigastric venae comitantes as vein grafts. Two subse-

quent TRAM flaps were noted to be congested. With the

experience of using the deep inferior epigastric venae co-

mitantes as vein grafts for arterial supercharging, one of

the venae comitantes was used with confidence for ve-

nous reconstruction and augmentation of venous outflow.

This series of six patients was reported in a previous

poster presentation.7

The utility of the use of a vena comitant from within

a free flap’s pedicle was confirmed in the two free flaps

in this series. Based on the experience of selectively arte-

rially supercharging or augmenting venous outflow in

TRAM flaps, one of the venae comitantes of the deep in-

ferior epigastric pedicle was successfully used as a vein

graft for venous reconstruction in a DIEP flap threatened

with venous thrombosis. The venae comitantes accompa-

nying the deep inferior epigastric artery are usually of

relatively large caliber and good quality. However, the

concept of the use of a vena comitant as a vein graft for

arterial reconstruction in a flap not based on the deep in-

ferior epigastric pedicle was successfully demonstrated in

the gracilis free flap used for calcaneal reconstruction.

A vena comitant is likely available for use as a vein

graft in flaps with the usual configuration of paired venae

comitantes within the vascular pedicle. However, using

one of a flap’s pedicle venae comitantes as a vein graft

should be considered with caution. In each of the cases

Flap Pedicle Vena Comitant as a Vein Graft 117

Microsurgery DOI 10.1002/micr

included here, the segment of vena comitant harvested

was expendable, such as with the supercharged or venous

augmented TRAM flaps, or was used when only one ve-

nous anastomosis was to be used for free-tissue transfer

venous outflow. Adequate flap venous outflow from the

remaining intact vena comitant and recipient vein must

be assured before sacrificing the potential for a second

venous anastomosis.

Additional caution is warranted before considering the

flap’s pedicle as a vein graft source. Pedicle anatomy

should be closely examined. Our experience in using a

pedicle vena comitant as a vein graft has been limited to

only two different vascular pedicles. Seven of the eight

cases reported involved the use of the deep inferior epi-

gastric artery pedicle. Two venae comitantes which

merge into a single vein a short distance from the exter-

nal iliac vein is the expected anatomy. Two venae comi-

tantes were also found in the pedicle of the single gracilis

muscle flap reported here and is a common pedicle anat-

omy for many flaps used in microvascular surgery. How-

ever, each pedicle must be considered independently to

determine if a vena comitant can be sacrificed without

jeopardy to the venous outflow of the flap and is of

adequate caliber and length to be used as vein graft. The

length of the needed vein graft must also be considered.

A vena comitant graft is limited to the length of the pedi-

cle at most.

CONCLUSIONS

We confirm that a vena comitant from within a flap’s

pedicle can be used as a vein graft source in selected mi-

crovascular cases. A short to moderate length vein graft

can be harvested when paired venae comitantes are

found. Vena comitant vein grafts can be used for arterial

or venous reconstruction. Potentially, a vena comitant

graft could be used for arterial and venous reconstruction,

although this was not necessary in any of the eight

patients presented here. The advantages include the

potential for optimal vessel size match and the avoidance

of an additional operative site and procedure. However,

caution is warranted when considering the use of a pedi-

cle’s vena comitant as a vein graft source. Venous out-

flow of the flap must be assured either through a remain-

ing vena comitant or an alternate pedicle. A second ve-

nous anastomosis is most likely precluded with this

technique.

REFERENCES

1. Mitz V, Staub S, Morel-Fatio D. Advantages of interpositional longvenous grafts in microvascular surgery. Ann Plast Surg 1978;2:16–23.

2. Miller MJ, Schusterman MA, Reece GP, Kroll SS. Interposition veingrafting in head and neck reconstructive microsurgery. J ReconstrMicrosurg 1993;9:245–251.

3. Buncke HJ, Alpert B, Shah KG. Microvascular grafting. Clin PlastSurg 1978;5:185–194.

4. Biemer E. Vein grafts in microvascular surgery. Br J Plast Surg1977;30:197–199.

5. Al Gattan MM, Boyd JB. Use of a vena comitans as a vein graft indigital replantation. Microsurgery 1994;15:149.

6. Hallock GG. Venae comitantes as a source of vein grafts. J ReconstrMicrosurg 2007;23:219–223.

7. Stewart DH, Stewart A, Vasconez HC, Fink B. Selective arterial orvenous augmentation of the TRAM flap using the inferior epigastricvena comitantes as vein graft. Poster presented at the Annual Scien-tific Meeting of the American Society for Reconstructive Microsur-gery, Puerto Rico, January 15–18, 2005.

118 Stewart et al.

Microsurgery DOI 10.1002/micr