The effect of traction force on eyelid blood perfusion during closure of defects

PURPOSE

In oculoplastic surgery the eyelid tissue is frequently stretched in order to repair defects after tumor surgery. However, there is a paucity of research regarding how stretching affects eyelids. The purpose of this study was to gain insight into how traction force affects eyelid stretch as well as tissue perfusion, using a laser-based in vivo monitoring technique.

METHOD

Lower-lid pentagonal resections were performed in eight patients and a total of nine eyelids. The medial section of the eyelid was then stretched using a dynamometer up to a force of 2.3 Newtons (N), and eyelid stretching and blood perfusion were continuously measured using laser speckle contrast imaging.

RESULTS

Tissue perfusion decreased exponentially when eyelid tissue was stretched, with an initial sharp decline followed by a more gradual reduction. Perfusion approached zero at a force of approximately 2.0 N. The length of the eyelid increased with increasing force up to 1.5 N, after which there was only a very slight increase in length.

CONCLUSIONS

Eyelid tissue seems to respond to traction in a non-linear fashion, where the initial force results in the greatest eyelid stretching and reduction in blood perfusion. The results provide information on the effects of a large force for direct closure of large eyelid defects. Considering how quickly perfusion approaches zero, the high success rate of eyelid reconstruction surgery is likely a testament to the extensive vascularization of the periocular region.

Perfusion Monitoring During Oculoplastic Reconstructive Surgery: A Comprehensive Review

PURPOSE

Knowledge of how blood perfusion is affected during and after reconstructive surgery is of great importance to predict the survival of grafts and flaps. When commonly used reconstructive procedures were developed a century ago, they were based on empirical observations of clinical outcome.

METHODS

This is a comprehensive literature review that summarizes the current state of knowledge regarding microvascular perfusion monitoring during oculoplastic procedures.

RESULTS

Over the years, a number of techniques for perfusion monitoring have been developed as an attempt to be more objective than clinical examination using traditional methods such as observations of skin temperature, turgor, color, smell, and capillary refill time. There are limited publications regarding microvascular perfusion monitoring during reconstructive procedures in the periocular area. Modern laser-based techniques have been attractive due to their noninvasive nature.

CONCLUSIONS

Today, modern, noninvasive techniques are available to monitor perfusion during and after surgery. This has increased our knowledge on the perfusion in common oculoplastic surgery procedures. A detailed understanding of how blood perfusion is affected will hopefully allow the improvement of surgical techniques for better clinical outcome.

Mapping of Perfusion During Full-Thickness Blepharotomy Using Laser Speckle Contrast Imaging

PURPOSE

The aim of this study was to monitor how the blood perfusion in human upper eyelids is affected during full-thickness blepharotomy.

METHODS

Seven eyelids in 5 patients with upper eyelid retraction due to Graves' disease underwent full-thickness blepharotomy. Perfusion was measured using laser speckle contrast imaging in the eyelid margin and in the conjunctival pedicle.

RESULTS

Immediately following the procedure, a nonsignificant reduction in perfusion was observed in the skin of the pretarsal eyelid margin, being 66% of the initial value ( p = n.s.). However, a statistically significant decrease in perfusion, to 53% of the initial value ( p < 0.01), was seen in the central pedicle of the conjunctiva. There were no surgical complications such as infection, signs of ischemia, or bleeding.

CONCLUSIONS

In this study, eyelid perfusion was mapped during full-thickness blepharotomy for the first time using laser speckle contrast imaging. The results showed that perfusion is sufficiently preserved during surgery, probably due to the rich vascular supply in the periocular region, which may explain the low risk of postoperative complications such as ischemia and infection.

Laser Speckle Contrast Imaging of the Blood Perfusion in Glabellar Flaps Used to Repair Medial Canthal Defects

BACKGROUND

The glabellar flap is a common technique for surgical repair after tumor excision in the medial canthal area. However, the outcome may be affected by partial flap necrosis. Little is known about the impact of surgery on blood perfusion and the postoperative course of reperfusion due to the absence of reliable and noninvasive perfusion monitoring techniques. The aim of this study was to use a modern imaging technique to assess blood perfusion in glabellar flaps.

METHODS

Glabellar flaps were used to repair medial canthal defects following tumor excision in 7 patients. Blood perfusion was monitored using laser speckle contrast imaging: during surgery, immediately postoperatively (0 weeks), and at follow-up, 1, 3, and 6 weeks after surgery.

RESULTS

Perfusion decreased gradually along the length of the flap, and reached a minimum 15 mm from the flap base. Perfusion in the proximal 20 mm of the flap was completely restored after 1 week, while the distal part of the flap was gradually reperfused over 6 weeks. Both the functional and esthetic surgical outcomes were excellent.

CONCLUSIONS

The rapid reperfusion of the glabellar flap may be explained by its connection to the vascular network via the flap pedicle. In flaps longer than 20 mm, the distal part can be considered a free skin transplant, and a combination of a glabellar flap and a free skin graft could then be considered.

Blood Perfusion of Human Upper Eyelid Skin Flaps Is Better in Myocutaneous than in Cutaneous Flaps

BACKGROUND

The aim of this study was to monitor blood perfusion in human upper eyelid skin flaps and examine how the perfusion is affected by the thickness of the flap.

METHODS

Twenty upper eyelids were dissected as part of a blepharoplasty procedure in patients. The medial end of the blepharoplasty flap remained attached to mimic a flap design often used in reconstruction in the periocular area, a myocutaneous flap in which the blood supply follows the fibers of the orbicularis muscle and is thus parallel to the long axis of the flap. The muscle was thereafter dissected from the flap to create a cutaneous flap. Blood perfusion in the 2 types of flaps was compared using laser speckle contrast imaging.

RESULTS

Blood perfusion decreased gradually from the base to the tip of all the flaps. Perfusion was significantly higher in the myocutaneous flaps than in the cutaneous flaps (p < 0.0004): 69% in the myocutaneous flaps and 43% in the cutaneous flaps, measured 5 mm from the base. Blood perfusion was preserved to a greater extent distally in the myocutaneous flaps (minimum value seen at 25 mm) than in the cutaneous flaps (minimum seen at 11 mm).

CONCLUSIONS

Blood perfusion was better preserved in myocutaneous flaps, including both skin and the orbicularis oculi muscle, than in cutaneous flaps. This may be of clinical interest in patients with poor microcirculation in which a long flap is required for reconstructive surgery.

The Effect of Canthotomy on Blood Perfusion During the Repair of Lower Eyelid Defects

PURPOSE

Canthotomy is frequently used to mobilize extra tissue when repairing larger lower eyelid defects. The aim of this study was to explore the effect of canthotomy on blood perfusion and oxygen tension.

METHODS

Eight pigs underwent a wedge resection of the lower eyelid and canthotomy (with cantholysis involving the lateral palpebral artery). The wedge resection was performed 8, 6, and 4 mm from the canthotomy. Perfusion and oxygen tension were monitored in the eyelid between the wedge resection and canthotomy using laser Doppler velocimetry and a Clark electrode. Verapamil was administered, and measurements were also performed 12 hours after surgery, to investigate the possible effects of vasospasm RESULTS:: The wedge resection alone did not affect perfusion. Canthotomy led to a reduction in perfusion; being 60% when the length of remaining eyelid was 8 mm, 32% when it was 6 mm, and 24% when it was 4 mm. Similar results were observed for oxygen tension. Vasospasm did not affect the results.

CONCLUSIONS

Canthotomy in combination with a wedge resection of the lower eyelid affects blood perfusion. A smaller length of remaining eyelid tissue will have less perfusion. This may not have any implications in cases of direct closure, but may play a role when the eyelid is to provide oxygen and nutrients to avascular grafts.