Christopher Hoe-Kong Chui

Correction of nipple inversion using a micro-knife and transverse to longitudinal skin closure

Through a series of 7 patients (8 nipples), we present a technique for the correction of nipple inversion. We use a micro-knife to divide the shortened ducts and fibrous tissues, as well as an internal cerclage suture and reverse strictureplasty skin closure to effectively correct and maintain the position of the inverted nipple. The advantages of the proposed technique include its simplicity, effectiveness in severe cases, and long-lasting results.

The chicken aorta as a simulation-training model for microvascular surgery training.

As a technically demanding skill, microsurgery is taught in the lab, in the form of a course of variable length (depending on the centre). Microsurgical training courses usually use a mixture of non-living and live animal simulation models. In the literature, a plethora of microsurgical training models have been described, ranging from low to high fidelity models. Given the high costs associated with live animal models, cheaper alternatives are coming into vogue. In this paper we describe the use of the chicken aorta as a simple and cost effective low fidelity microsurgical simulation model for training.

Early Prediction of Skin Viability Using Visible Diffuse Reflectance Spectroscopy and Autofluorescence Spectroscopy

Background: Accurate and early prediction of skin flap viability is vitally important in reconstructive surgery. To the best of the authors’ knowledge, this is the first pilot study to evaluate the simultaneous use of both visible diffuse reflectance and autofluorescence spectroscopy on a reverse MacFarlane rat dorsal skin flap model in the early prediction of skin viability. Methods: A total of 62 flap measurement sites from 11 Sprague-Dawley rats were monitored for 72 hours. Both statistical analysis using measured spectra and quantification of physiologically relevant tissue parameters using empirical methods were performed. Results: The statistical analysis results suggest that either visible diffuse reflectance spectroscopy or autofluorescence spectroscopy alone can predict the skin viability accurately; however, autofluorescence spectroscopy is more sensitive to tissue changes in the first 2 hours after induction of ischemia. The pilot study shows that it is feasible to predict flap failures in the first 2 hours when using autofluorescence spectroscopy alone; moreover, it is possible to predict flap failures even in the first 15 minutes with high accuracy when using diffuse reflectance and autofluorescence spectroscopy simultaneously. Meanwhile, several physiologically relevant parameters including hemoglobin oxygenation, total hemoglobin concentration, and redox ratio indicators estimated from diffuse reflectance and autofluorescence spectra show distinctively different trends over time for nonviable and viable skin. Conclusions: These findings will be helpful to clinicians for making a precise judgment on flap viability. Furthermore, the authors’ results highlight the advantage of using autofluorescence spectroscopy in the early prediction of skin flap viability relative to diffuse reflectance spectroscopy.

Use of the fix and flap approach to complex open elbow injury: the role of the free anterolateral thigh flap.

Background Complex elbow injuries with associated nerve, muscle, or joint injury commonly develop post-inury stiffness. In order to preserve function, joint congruency, elbow stability and durable wound coverage must be achieved in a timely manner. Methods A retrospective review of patients who underwent orthopaedic fixation followed by free anterolateral thigh (ALT) flap soft tissue coverage was performed. Five patients were identified and included in this study. Results We present a series of 5 cases managed with this principle. Soft tissue defects ranged in size from 4×9 cm (36 cm2) to 15×30 cm (450 cm2) and were located either posteriorly (n=4) or anteriorly (n=1). Associated injuries included open fractures (n=3) and motor nerve transection (n=2). Wound coverage was achieved in a mean duration of 18.8 days (range, 11 to 42 day). There were no flap failures and no major complications. The mean postoperative active elbow motion was 102° (range, 45° to 140°). Conclusions In our small series we have highlighted the safety and utility of using the free ALT flap in complex elbow injuries. The ALT flap has many advantages which include abundant skin and subcutaneous tissue; vascularised vastus lateralis muscle that was used in our series to obliterate dead space, provide a vascular bed for nerve grafts and combat infection; and, access to fascia lata grafts for reconstruction of the triceps tendon.

Early detection and differentiation of venous and arterial occlusion in skin flaps using visible diffuse reflectance spectroscopy and autofluorescence spectroscopy.

Our previous preclinical study demonstrated that both visible diffuse reflectance and autofluorescence spectroscopy, each of which yields a different set of physiological information, can predict skin flap viability with high accuracy in a MacFarlane rat dorsal skin flap model. In this report, we further evaluated our technique for the early detection and differentiation of venous occlusion and arterial occlusion in a rat groin flap model. We performed both diffuse reflectance and autofluorescence measurements on the skin flap model and statistically differentiated between flaps with and without occlusions as well as between flaps with venous occlusion and those with arterial occlusion based on these non-invasive optical measurements. Our preliminary results suggested that visible diffuse reflectance and autofluorescence spectroscopy can be potentially used clinically to detect both venous and arterial occlusion and differentiate one from the other accurately at an early time point.

Two-Stage Latissimus Dorsi Flap with Implant for Unilateral Breast Reconstruction: Getting the Size Right.

Background The aim of unilateral breast reconstruction after mastectomy is to craft a natural-looking breast with symmetry. The latissimus dorsi (LD) flap with implant is an established technique for this purpose. However, it is challenging to obtain adequate volume and satisfactory aesthetic results using a one-stage operation when considering factors such as muscle atrophy, wound dehiscence and excessive scarring. The two-stage reconstruction addresses these difficulties by using a tissue expander to gradually enlarge the skin pocket which eventually holds an appropriately sized implant. Methods We analyzed nine patients who underwent unilateral two-stage LD reconstruction. In the first stage, an expander was placed along with the LD flap to reconstruct the mastectomy defect, followed by gradual tissue expansion to achieve overexpansion of the skin pocket. The final implant volume was determined by measuring the residual expander volume after aspirating the excess saline. Finally, the expander was replaced with the chosen implant. Results The average volume of tissue expansion was 460 mL. The resultant expansion allowed an implant ranging in volume from 255 to 420 mL to be placed alongside the LD muscle. Seven patients scored less than six on the relative breast retraction assessment formula for breast symmetry, indicating excellent breast symmetry. The remaining two patients scored between six and eight, indicating good symmetry. Conclusions This approach allows the size of the eventual implant to be estimated after the skin pocket has healed completely and the LD muscle has undergone natural atrophy. Optimal reconstruction results were achieved using this approach.

Spectral diffuse reflectance and autofluorescence imaging can perform early prediction of blood vessel occlusion in skin flaps

Flap transfer has become a common technique in reconstructive surgery. However, a significant number of compromised skin flaps are not successfully salvaged because the current clinical method for flap assessment relies heavily on the clinicians experience. Vascular occlusion is the major reason for flap failure, thus the accurate and objective early prediction of blood vessel occlusion is vitally important. Our parallel point measurement study has demonstrated the great potential of joint diffuse reflectance and autofluorescence spectroscopy in the early detection and differentiation of venous and arterial occlusion in skin flaps. Unfortunately, the technique of point measurements is not suitable to examine a large skin flap when a high spatial resolution is required. In this study, we attempted to overcome this problem by performing spectral diffuse reflectance and autofluorescence imaging on a rat skin flap model. Both imaging data and reconstructed spectra were used to statistically differentiate control flaps, arterially occluded flaps and venously occluded flaps. Our preliminary results suggest that the technique of joint diffuse reflectance and autofluorescence spectroscopic imaging can achieve high classification accuracy thus could be used to detect and differentiate flaps with venous and arterial occlusion accurately at an early time point in a large skin flap. Typical reconstructed spectra of (a) diffuse reflectance and (b) autofluorescence after normalization.

Maximizing Outcomes While Minimizing Morbidity: An Illustrated Case Review of Elbow Soft Tissue Reconstruction

Background. Injuries to the elbow have led to consequences varying from significant limitation in function to loss of the entire upper limb. Soft tissue reconstruction with durable and pliable coverage balanced with the ability to mobilize the joint early to optimize rehabilitation outcomes is paramount. Methods. Methods of flap reconstruction have evolved from local and pedicled flaps to perforator-based flaps and free tissue transfer. Here we performed a review of 20 patients who have undergone flap reconstruction of the elbow at our institution. Discussion. 20 consecutive patients were identified and included in this study. Flap types include local (n = 5), regional pedicled (n = 7), and free (n = 8) flaps. The average size of defect was 138 cm2 (range 36–420 cm2). There were no flap failures in our series, and, at follow-up, the average range of movement of elbow flexion was 100°. Results. While the pedicled latissimus dorsi flap is the workhorse for elbow soft tissue coverage, advancements in microvascular knowledge and surgery have brought about great benefit, with the use of perforator flaps and free tissue transfer for wound coverage. Conclusion. We present here our case series on elbow reconstruction and an abbreviated algorithm on flap choice, highlighting our decision making process in the selection of safe flap choice for soft tissue elbow reconstruction.

Assessment of skin flap viability using visible diffuse reflectance spectroscopy and auto-fluorescence spectroscopy

The accurate assessment of skin flap viability is vitally important in reconstructive surgery. Early identification of vascular compromise increases the change of successful flap salvage. The ability to determine tissue viability intraoperatively is also extremely useful when the reconstructive surgeon must decide how to inset the flap and whether any tissue must be discarded. Visible diffuse reflectance and auto-fluorescence spectroscopy, which yield different sets of biochemical information, have not been used in the characterization of skin flap viability simultaneously to our best knowledge. We performed both diffuse reflectance and fluorescence measurements on a reverse MacFarlane rat dorsal skin flap model to identify the additional value of auto-fluorescence spectroscopy to the assessment of flap viability. Our result suggests that auto-fluorescence spectroscopy appears to be more sensitive to early biochemical changes in a failed flap than diffuse reflectance spectroscopy, which could be a valuable complement to diffuse reflectance spectroscopy for the assessment of flap viability.

Connecting tube-drains to a V.A.C. system: an effective alternative to wall suction.

Despite the proper placing of tube-drains following microsurgical flap surgery, adequate suction is sometimes not achieved and complications such as seroma or haematoma may occur. This is because the conventional tube-drain and bottle setup is unable to cope with wounds communicating with the surface, or those with multiple interconnecting pockets. We describe a modified technique to achieve optimal drainage when vacuum bottles are overcome. The drains are placed as normal and attached to vacuum bottles. If they fail, the same tubes are then connected to a Vacuum Assisted Closure (V.A.C. ) system (Kinetic Concepts Inc., San Antonio, TX, USA) through an adapted V.A.C. sponge. This provides constant mechanical suction, with the option of precise calibration to match fluid leakage rates. Where drainage is required over delicate tissues, such as in the mediastinum, it is preferable to use lower pressures (around 100 mm Hg) and increase only as necessary. With bottles, human intervention is required to assess continuing function and reset suction when needed. With a V.A.C. system this need is largely removed as it automatically self-adjusts, maintaining the user defined pressure, compensating for any leak. This continual suction also allows tissue pockets to self-seal via a flap-valve mechanism, whereas suction from bottles will tail off. Currently, bottle failure can be partially addressed by connecting drains to a wall vacuum source. However, these cannot be easily fine-tuned and require constant attention from trained staff. The system described allows intraoperative establishment of adequate suction, as opposed to relying on it being achieved postoperatively using a wall source on the ward, where there is no option to re-explore the wound or re-site drains. To assemble the equipment, make a series of small holes in the distal 2 cm of the free end of the tube-drains and insert them into small stab incisions in a V.A.C. sponge. An OpSite (Smith & Nephew Healthcare, Hull, UK) dressing is then used to sandwich the sponge and the V.A.C. system can be connected. Later, redundant drains can be removed