Giovanni Papa

Improved Survival of Ischemic Cutaneous and Musculocutaneous Flaps after Vascular Endothelial Growth Factor Gene Transfer Using Adeno-Associated Virus Vectors

A major challenge in reconstructive surgery is flap ischemia, which might benefit from induction of therapeutic angiogenesis. Here we demonstrate the effect of an adeno-associated virus (AAV) vector delivering vascular endothelial growth factor (VEGF)165 in two widely recognized in vivo flap models. For the epigastric flap model, animals were injected subcutaneously with 1.5 x 10(11) particles of AAV-VEGF at day 0, 7, or 14 before flap dissection. In the transverse rectus abdominis musculocutaneous flap model, AAV-VEGF was injected intramuscularly. The delivery of AAV-VEGF significantly improved flap survival in both models, reducing necrosis in all treatment groups compared to controls. The most notable results were obtained by administering the vector 14 days before flap dissection. In the transverse rectus abdominis musculocutaneous flap model, AAV-VEGF reduced the necrotic area by >50% at 1 week after surgery, with a highly significant improvement in the healing process throughout the following 2 weeks. The therapeutic effect of AAV-VEGF on flap survival was confirmed by histological evidence of neoangiogenesis in the formation of large numbers of CD31-positive capillaries and alpha-smooth muscle actin-positive arteriolae, particularly evident at the border between viable and necrotic tissue. These results underscore the efficacy of VEGF-induced neovascularization for the prevention of tissue ischemia and the improvement of flap survival in reconstructive surgery.

Effect of vascular endothelial growth factor gene therapy on post-traumatic peripheral nerve regeneration and denervation-related muscle atrophy

Functional recovery after peripheral nerve injury depends on both improvement of nerve regeneration and prevention of denervation-related skeletal muscle atrophy. To reach these goals, in this study we overexpressed vascular endothelial growth factor (VEGF) by means of local gene transfer with adeno-associated virus (AAV). Local gene transfer in the regenerating peripheral nerve was obtained by reconstructing a 1-cm-long rat median nerve defect using a vein segment filled with skeletal muscle fibers that have been previously injected with either AAV2-VEGF or AAV2-LacZ, and the morphofunctional outcome of nerve regeneration was assessed 3 months after surgery. Surprisingly, results showed that overexpression of VEGF in the muscle-vein-combined guide led to a worse nerve regeneration in comparison with AAV-LacZ controls. Local gene transfer in the denervated muscle was obtained by direct injection of either AAV2-VEGF or AAV2-LacZ in the flexor digitorum sublimis muscle after median nerve transection and results showed a significantly lower progression of muscle atrophy in AAV2-VEGF-treated muscles in comparison with muscles treated with AAV2-LacZ. Altogether, our results suggest that local delivery of VEGF by AAV2-VEGF-injected transplanted muscle fibers do not represent a rational approach to promote axonal regeneration along a venous nerve guide. By contrast, AAV2-VEGF direct local injection in denervated skeletal muscle significantly attenuates denervation-related atrophy, thus representing a promising strategy for improving the outcome of post-traumatic neuromuscular recovery after nerve injury and repair.

Full-Thickness Skin Burn Caused by Radiofrequency Ablation of a Benign Thyroid Nodule

Dear Editor: Today, radiofrequency ablation (RFA) represents an effective therapeutic option for symptomatic benign thyroid nodules. The advantages of this outpatient treatment modality include reduced morbidity, no risk of cosmetic damage, and decreased costs (1). In Trieste, we started using RFA for symptomatic thyroid nodule ablation in 2012, and so far, 107 patients have been treated with this approach, with overall satisfactory results and a low complication rate (3%), which is consistent with the literature (1–3). All the procedures were performed by the same operator, who is a well-trained radiologist, experienced in ultrasound (US), fine-needle aspiration biopsy, and RFA procedures. Nevertheless, in one of these patients (0.9%), the procedure unexpectedly caused (3,4) a third-degree skin burn. Here, we report our experience. A healthy 34-year-old woman with a slim body habitus presented with a thyroid nodule located in the left inferior pole of the gland, which was partly plunging (Supplementary Fig. S1; Supplementary Data are available online at www.liebertpub.com/thy). On presentation, she complained of local cosmetic concerns, seeking advice on the best treatment modality of her nodule. The nodule measured 42 mm × 40 mm × 23 mm (Supplementary Fig. S2A) and was cytologically benign. Given that she refused surgery and met all the eligibility criteria for thyroid RFA (5), we suggested that she undergo this procedure. The patient was informed and prepared as already described (1,2). Before the procedure, she underwent local anesthesia at the puncture site with 10 mL of 2% lidocaine, as well as conscious sedation with 2 mg of midazolam. To ablate the nodule, a monopolar electrode featuring a shaft length of 10 cm and an exposed tip length of 10 mm (RF AMICA_PROBE model RFH18100V1, HS Hospital Service SpA, Italy) was inserted into the thyroid nodule under US guidance. In particular, due to the position of the nodule (Supplementary Fig. S1), the electrode was inserted directly into the nodule from above (direct approach), instead of reaching it through the thyroid isthmus (transisthmic approach). We began by ablating the central areas of the nodule (Supplementary Fig. S2B) with an initial RF power of 30 W, which was then increased to 40 W. Then, in order to treat the other parts of the nodule, the electrode was moved and pulled slightly backward. Probably at that moment, the active needle tip must have come in close proximity to the skin with the power delivery possibly not switched off yet, so that a skin burn developed. The lesion was noticed by the operator immediately after it developed, and as soon as it was noticed the procedure was stopped, leaving most of the nodule untreated (Supplementary Fig. S2C). Otherwise, the patient did not perceive anything and she did not complain of pain during the skin injury because of the conscious sedation and local anesthesia. No other complications were encountered. Initially, the lesion appeared as a full-thickness burn that surrounded the electrode puncture site, with a maximum diameter of 1.5 cm and a charred white necrotic core (Fig. 1A). The patient was seen by a plastic surgeon who recommended treatment with topical gentamicin sulfate and hyaluronic acid for the first week, in order to reduce the risk of bacterial colonization of the wound and to help tissue regeneration and wound healing. The following week, the patient started applying an activated charcoal cloth with silver. Then, after surgical debridement of the wound (Fig. 1B), the skin burn was treated with a collagen wound dressing for another two weeks. Overall, although this skin burn took more than one month to heal, its final appearance looked almost like the normal skin (Fig. 1C). FIG. 1. (A) Baseline image of the radiofrequency ablation–induced full-thickness burn, which looks like a coin, with a maximum diameter of 1.5 cm and a charred white necrotic core. (B) Image of the neck after the surgical debridement of the wound. ... To our knowledge, this is the first report of a full-thickness skin burn caused by RFA of a benign thyroid nodule. The RFA-induced skin burns that have been reported so far were usually of first degree, and patients recovered within seven days (3–4). Here, we describe this clinical experience to raise awareness that RFA can also lead—although rarely—to full-thickness burns that take at least three weeks to heal and usually develop a scar, which may be severe. Patients should be informed of this extremely infrequent but regrettable possibility as well as its remedies, especially if they are undergoing RFA because of cosmetic concerns (and they want to avoid surgical scars). In order to prevent such a complication, it is important to keep the active needle tip within the nodule. To do so, it is recommended to use the transisthmic approach whenever possible. It can also be useful to inject cold fluid in the subcutaneous layers under the puncture site in order to create a wheal that will raise the skin and increase the distance from the nodule (we generally do that when injecting the lidocaine). It is also suggested (3) to apply an ice bag on the skin next to the puncture site during the ablation. In any case, it is important to keep in mind that conscious sedation may delay the detection of complications, and it is important to pay attention when treating superficial nodules in lean patients, where the active needle tip is more likely to come into contact with the skin. In cases when a skin burn develops, specific care will facilitate the wound healing process in order to achieve a satisfactory esthetic result.

How we fix free flaps to the bone in oral and oropharyngeal reconstructions.

PURPOSE The use of suture anchors has been described in orthopedic, hand, oculoplastic, temporomandibular joint and in aesthetic surgery, but no study reports the use of the Mitek® anchors (Depuy Mitek Surgical Products, Inc. Raynham, Massachusetts) for fixing the free flaps used in oncologic oral and oropharyngeal reconstruction. MATERIALS AND METHODS In this prospective non-randomized study, 9 patients underwent surgical resection of oral or oropharyngeal cancer followed by a free flap reconstruction; mini anchors were used to fix the flap directly to the bone. We collected data regarding the patients, the tumor stage, the surgical procedure, the radiotherapy and the number of anchors used. RESULTS The average follow-up was 28months (range 24-38).We observed no complications with trans-oral, sub-mandibular and trans-mandibular approach in both oral and oropharyngeal reconstructions. All anchors became osteo-integrated and no complications occurred after radiotherapy. CONCLUSIONS In our opinion this device favors free flap adhesion to the bone. We registered no postoperative complications related to the use of the device which looks suitable for use in irradiated tissues. The radiotherapy did not cause any long-term complications related to the use of Mitek® mini bone anchors.

Five Years of Experience Using a Dermal Substitute: Indications, Histologic Studies, and First Results Using a New Single‐Layer Tool

Background Dermal substitutes have been used in Europe since 1996 as a mean of reconstructing the dermal layer. Objectives To introduce the dermal substitute as a dual‐stage reconstructing procedure using the dual‐layer version and as a single‐stage procedure, combining the single layer with a skin graft to achieve immediate closure. Our further objective was to evaluate the persistence of a commercial dermal substitute in the hosts dermal layer using serial histologic studies. Materials and Methods The dermal substitute used was a membrane made using a porous coprecipitate of type I bovine collagen and glycosaminoglycan organized in a three‐dimensional structure that allows the hosts cell to migrate into it. It is available in a double‐layer structure, covered by a silicone sheet, and in a single‐layer structure without silicon. Results and Conclusion We describe the dermal substitute indications in dermatologic surgery and our first results with the single layer as a single‐stage procedure with an 80% to 100% take rate. Our histological studies of both products show their perfect integration and the persistence of the peculiar three‐dimensional structure (neodermis) 5 years from implantation of the dual‐layer dermal substitute. The authors have indicated no significant interest with commercial supporters.

The Use of Near Infrared Spectroscopy (NIRS) for Monitoring of Free Flaps

Ever since the introduction of free flaps in reconstructive plastic surgery, the success rates have improved. Nevertheless, postoperative complications leading to flap failure still occur in 6–25 % of cases. As salvage rate depends on the time interval from vascular impairment to surgical reintervention (revision), alternative monitoring devices have been introduced in order to detect flap vascular impairment before their clinical signs become evident. Near infrared spectroscopy (NIRS) has proven to be effective. It is non-invasive, reliable, simple to use, objective, recordable, capable of prolonged continuous monitoring and rapidly responds to circulatory changes. The introduction of this device led to improvement of salvage rates and overall flap survival in our department.

Treatment of Subacute Traumatic Lower Limb Wounds by Assisted Healing and Delayed Selective Reconstruction

From 2007 to 2017, 34 patients with subacute wounds to lower limbs were treated by the assisted healing and delayed selective reconstruction method (AH-GSR). Sixteen patients (47%) presented with a concomitant fracture; 18 patients (53%) sustained degloving with a soft tissue injury only. Negative pressure wound therapy was used in 28 patients (82.3%). Antibiotics were given to all patients, in 12 (35.3%) as prophylaxis and in 22 (64.7%) as therapy. The reconstruction was performed by split-thickness skin grafts (SG) in 16 patients (47%), by dermal substitutes (DS) in 8 patients (23.5%), by local fascio-cutaneous flaps in 2 patients (5.9%), and by free flaps in 8 patients (23.5%). In this case series, three (8.8%) complications were recorded. Adhering to the AH-GSR method of treatment of lower extremities subacute wounds guarantees results comparable to the ones obtained with the treatment of acute wounds during the first week after injury.

Limb and Flap Salvage in Gustilo IIIC Injuries Treated by Vascular Repair and Emergency Free Flap Transfer

Background Gustilo classification system defines IIIC fractures as open fractures associated with an arterial injury that requires repair. The aim of our study was to analyze the early outcome in terms of limb and flap salvage, early amputation, and early complication rate in patients with Gustilo IIIC open fractures treated in an emergency setup. Methods We retrospectively reviewed 20 patients with Gustilo IIIC injuries treated by the “fix and flap” principle during the first surgical procedure in the first 24 hours after injury (emergency free flap transfer). All patients underwent surgery with radical debridement, wound irrigation, skeletal stabilization, vascular repair, and immediate free flap coverage. Results In this study, 18 patients were men (90%) and 2 were women (10%). In all patients, a vascular repair was performed and in 17 cases (85%), the lower limb/foot was avascular and limb salvage was performed. Three patients had one vessels injured (15%) and 17 had two or three vessels injured (85%). In 9 out of 20 (45%), a revision surgery was needed for arterial (10%, 2 patients), arterial‐venous (15%, 3 patients), and venous thrombosis (20%, 4 patients), while 4 patients required an early amputation (20%) and 1, a late one (5%). In three patients (15%), a flap loss occurred. Superficial infection occurred in seven cases (35%) and deep infection (osteomyelitis) in one (5%). Conclusion A single‐stage procedure performed in an emergency operating room could lead to an effective outcome with a high rate of limb salvage and satisfying long‐term results.

Is it possible to calculate surface areas of intraoral structures from preoperative CT scan

Microsurgical reconstruction of intraoral structures requires accurate planning of flap shape and dimensions. The goal of this study is to describe a method that allows to calculate surfaces of oral structures from preoperative CT-scan in order to determine a precise flap design before the surgery. We created casts of the human mouth from cadavers with a head and neck CT-scan available using an impression material. We digitalized the mouth casts and unwrapped the surfaces of the different structures of the mouth in a bi-dimensional plane in order to measure the area. Furthermore, we measured distances from pre-determined bony landmarks using the CT-scan 3D reconstruction model and we correlated the two type of measurements. We performed a simple regression analysis and afterwards a multivariate analysis using the more statistically correlated measurements. We found a statistical correlation between the surface of the tongue and the surface floor of the mouth with three bone distances that let us to create three mathematical formulas. With those formulas, we can calculate the surfaces of the tongue and the floor of the mouth using simple bony distances that can be easily measured from the head and neck preoperative CT scan. Using standard templates layouts, we can create a precise preoperative flap design in the reconstruction of the tongue and of the floor of the mouth.

Assisted Healing–Selective Delayed Reconstruction for Subacute Traumatic Wounds of the Lower Limb

1 BACKGROUND Patients often are being referred to plastic surgery for reconstruction of complex wounds in the subacute phase of healing. According to Godina,1 the time interval for the acute reconstruction (early free flaps) is less than 72 hours.2 Byrd et al,3 however, believe that the acute period of the wound lasts 1 week. Only after that, the wound enters in the subacute phase in which treatment of complex wounds becomes more prone to complications (bone and soft-tissue infection, free flap failure).