Journal of Plastic, Reconstructive & Aesthetic Surgery (2010) 63, e582ee583

CORRESPONDENCE AND COMMUNICATION

Response to letter: Gravitationalretrograde venous perfusion -a technique for limb extremitysalvage when microvasculararterial repair is not possible.J Plast Reconstr Aesthet Surg2010;63:e422ee423

Dear Ms Ferguson

Thank you for your correspondence. We would argue infavour of the retrograde venous perfusion hypothesis and Iwill outline the reasons for this.

Case 1. As outlined in the text, we accept that there mayhave been some terminal branches of the dorsal metacarpalarteries present in the dorsal skin attachment, but we failto see how this would be sufficient to adequately perfusethe entire digit. If this was the case, you would expectbleeding from the tips of the fingers due to arterial pres-sure. The effect of dependency is immediate, the dorsalveins filled and there was a capillary refill with associatedbleeding on pin-prick. We fail to see how lowering the handcould have had such a rapid effect if it was not for retro-grade venous inflow. Dependency led to progressive desa-turation of the blood in the tips consistent with stasis. Thiswas reversed immediately by elevating and lowering thehand which is consistent with a to-and-fro circulation viathe venous system.

Case 2. Based on the alternative hypothesis proposed,you would expect that the ideal position is the dependentposition as there is no obstruction to venous drainage. Thiswas not what we observed. We found that elevation fol-lowed by dependency quickly relieved the ischaemic painimproved the colour to the tips of the finger. We acceptthat the arterial inflow may be augmented by dependencybut if this is sufficient for viability, why did the finger tipsbecome critically ischaemic in the first place and why isthere such an immediate response to this technique?

DOI of original article: 10.1016/j.bjps.2009.10.022.

1748-6815/$-seefrontmatterª2010BritishAssociationofPlastic,Reconstrucdoi:10.1016/j.bjps.2009.12.017

Case 3. This case resulted in a distally based flap, whichwas attached to the base of the toes. We state in the textthat this flap probably had a weak arterial inflow and alsovenous drainage in a retrograde fashion. Clinically, the flapwas not viable based on this circulation. We state in thetext that the technique in this case supported the circula-tion by increasing both the venous inflow and arterialinflow. We believe the venous component was moreimportant in enabling tissue survival. We do not believethat simply changing the position will augment arterial flowto such an extent to explain the observed effect. Venouspooling/emptying is rapid and obvious in response topositioning.

The corresponding authors requested clarification on thedirection of flow in the venous networks in view of thevenous congestion.

In normal conditions, veins depend on positive pressurefor flow from the extremities back to the heart. This comesat the micro-circulation level from the venous side of thecapillary bed and venules.1,2 The muscle pump action andcompression in the foot and hand from movement is moreimportant for venous blood flow. Valves also are importantin directing flow and resisting the effect of gravity, butthere are several oscillating (avalvular) veins which enableretrograde flow.1,3 Congestion occurs in the cases describedbecause there is no arterial inflow, and no pump action.There is venous stasis and positioning is required to set upa to-fro circulation. In case 2 movement of the digits alsofacilitated venous flow.

The congestion we described in these cases was causedby raised hydrostatic pressure in the venous system inducedby dependency. It certainly wasn’t caused be venousobstruction. There were several intact dorsal veins, whichwould easily drain an ischaemic digit. A postulated expla-nation for the congestion seen in the distal part of the flapin case 3 after the regime was stopped at 5 days is outlinedin the discussion of the paper.

In these cases we believe there was minimal arterialinflow, but retrograde venous flow was sufficient to main-tain viability until a collateral circulation developed fromthe surrounding wound bed. If you accept that retrogradevenous flow is possible, it stands to reason that dependencywill result in filling of the extremity particularly in theabsence of arterial inflow as the pressure in the venules willbe low. Several scientific studies outlined in the text

tiveandAestheticSurgeons.PublishedbyElsevierLtd.All rightsreserved.

Correspondence and communication e583

provide in vivo evidence to support the hypothesis thattissue can survive based on retrograde venous perfusiononce a to-and-fro circulation is maintained to allow mixingof desaturated venous blood with more saturated venousblood.4,5

References

1. Monos E, Berczi V, Nadasy G. Local control of veins: biome-chanical, metabolic, and humeral aspects. Physiol Rev 1995;75:611e66.

2. Gardner AMN, Fox RH. The return of blood to the heart. London& Paris: John Libbey & Co; 1989.

3. Taylor GI, Caddy CM, Watterson PA, Crock JG. The venousterritories (venosomes) of the human body: experimental studyand clinical implications. Plast Reconstr Surg 1990;86:185e213.

4. Chavoin JP, Rouge D, Vachaud M, Boccalon H, Costagliola M.Island flaps with an exclusively venous pedicle. a report of

eleven cases and a preliminary haemodynamic study. Br J PlastSurg 1987;40:149e54.

5. Thatte MR, Kamdar NB, Khakkar DV, Varade MA, Thatte RL.Static and dynamic computerized radioactive tracer studies,vital dye staining and theoretical mathematical calculations toascertain the mode of survival of single cephalad channelvenous island flaps. Br J Plast Surg 1989;42:405e13.

K. PowerA. Turkmen

Department of Plastic and Reconstructive Surgery, SouthManchester University Hospital Trust, Southmoor Road,

Wythenshawe, Manchester, UKE-mail address: kieran_power@hotmail.com

D.A. McGroutherUniversity of Manchester, Blond McIndoe Laboratories,

Plastic and Reconstructive Surgery Research, 3.102 Stop-ford Building, Oxford Road, Manchester M13 9PT, UK