Yueh-Bih Tang

Posterior interosseous flap and its variations for coverage of hand wounds

BACKGROUND Conventional posterior interosseous flap has the disadvantage of partial or even complete necrosis of the flap when there is anatomical variation or contusion around its distal pedicle. To make it a more reliable flap, three types of auxiliary procedures were designed. METHODS (1) When there is congestion after inset of the distally based flap, an additional venous anastomosis was carried out. (2) When there is anatomical variation so that a distally based flap could not be raised without compromising the nerve branches, or when contusion was found around the distal pedicle, the flap was changed into a free flap. This design is also indicated for coverage of the distal fingers. (3) When the patient is elderly with possible peripheral arterial disease, the flap was raised with a wide base, incorporating the branches of both the anterior and posterior interosseous arteries. There were eight, 36, and five patients in each group, respectively. RESULTS There was only one failure in the free flap group. No partial necrosis of the flap was found. Other complications were analyzed. CONCLUSION With these backup procedures, the posterior interosseous flap can be more widely used with safety. By combining various reconstructive armaments, the result of a conventional procedure can be improved.

Stemness and transdifferentiation of adipose-derived stem cells using L-ascorbic acid 2-phosphate-induced cell sheet formation.

Cell sheet technology has emerged as an important tissue engineering approach. Adipose-derived stem cells (ASCs) have valuable applications in regenerative medicine, but their stemness and differentiation capabilities in the cell sheet format have not been well investigated. In this study, we found that l-ascorbate 2-phosphate (A2-P), a stable form of ascorbic acid, significantly enhanced ASC proliferation and induced ASC sheet fabrication in 7 days with abundant extracellular matrix deposition. Importantly, A2-P treatment significantly enhanced expression of pluripotent markers Sox-2, Oct-4 and Nanog, but treating ASCs with antioxidants other than A2-P revealed no stemness enhancement. Moreover, ASC treatment with A2-P and a collagen synthesis inhibitor, L-2-azetidine carboxylic acid or cis-4-hydroxy-d-proline, significantly inhibited the A2-P-enhanced expression of stemness markers. These findings demonstrated that A2-P enhances stemness of ASCs through collagen synthesis and cell sheet formation. We also showed that A2-P-stimulated collagen synthesis in ASCs may be mediated through ERK1/2 pathway. By culturing the ASC sheets in proper induction media, ASC transdifferentiation capabilities into neuron and hepatocyte-like cells were significantly enhanced after cell sheet formation, while adipogenic and osteogenic differentiation capacities were still maintained. Using a murine model of healing-impaired cutaneous wound, faster wound healing was noted in the group that received ASC sheet treatment, and we observed significantly more engrafted ASCs with evidence of differentiation toward endothelial and epidermal lineages in the cutaneous wound tissue. Therefore, A2-P-mediated ASC sheet formation enhanced ASC stemness and transdifferentiation capabilities, thereby representing a promising approach for applications in regenerative medicine.

Cross-leg free flaps for difficult cases of leg defects: indications, pitfalls, and long-term results.

BACKGROUND Cross-leg free flaps have been described for reconstruction of leg defects in cases of trauma with no suitable recipient vessels in the vicinity of the defect. The pitfalls, however, have not been well documented in the literature. The technique of transfer and the length of time required before pedicle division depend on the nature of the flap and the contact surface. METHODS Eight cross-leg free flap reconstructions were performed on seven patients between 1986 and 1993. These included three latissimus dorsi muscle flaps, three fibula osteomyocutaneous flaps, one tensor fascia lata myocutaneous flap, and one posterolateral thigh flap. The important technical considerations are outlined. RESULTS One latissimus dorsi flap failed, whereas the rest of the flaps completely survived. The morbidity of the recipient and donor sites are listed. CONCLUSION We conclude that the technique offers the possibility of salvaging limbs that are, otherwise, nonreconstructable. It is useful for young patients. When the flap is long, it can function as a nutrient flap for the distal limb even though the pedicle has been divided. It is a backup procedure in an urgent situation of re-exploration in which reestablishment of circulation should take place as soon as possible.

Microvascular free muscle flaps for chronic empyema with bronchopleural fistula when the major local muscles have been divided--one-stage operation with primary wound closure.

It should be emphasized that most cases of chest empyema can be successfully treated with conventional thoracic surgery procedures. For chronic empyema with a bronchopleural fistula complicated by previous division of major local muscles following repeated thoracotomies, free muscle flaps are employed. Five such cases treated with this method resulted in successful closure of the airway fistula, as well as complete obliteration of the empyema cavity in a single operation. This method is very effective in eradicating infection and achieves prompt wound healing, decreased morbidity, and gradual improvement of pulmonary function after surgery. Analysis of roentgen ray and computed tomographic scans before and after surgery shows lung expansion when the transferred muscles atrophy. The results are satisfactory. The method described here is not the only solution to this problem, but it is a new approach that has advantages not seen in conventional methods. It is indicated only in patients who have been operated on many times and who have no remaining available local muscles.

Microvascular prefabricated free skin flaps for esophageal reconstruction in difficult patients

BACKGROUND Reconstruction of the esophagus for complicated benign stricture or after resection of malignant lesion is still a challenge for surgeons. When abdominal viscera cannot be used, skin flaps are selected for esophageal reconstruction. However, skin flaps for esophageal reconstruction are notorious for leakage, and have not been widely accepted. Prefabrication before microvascular transfer to its final site can improve the result of esophageal reconstruction when skin flaps are used. METHODS Eight patients with complicated corrosive esophagitis had been treated with prefabricated skin flaps for esophageal reconstruction. The procedures are described in detail. RESULTS All patients healed well without leakage. The barium study showed smooth passage. There was no dysphasia or regurgitation after education. Pulmonary complication happened in only 1 patient. Revision for the distal anastomosis was required in 1 patient due to narrowing. When the skin tube is long, the patients need water (or soup) to facilitate swallowing and occasionally use their hand to help the food passage. This method has the following advantages: (1) healing of the long suture line before transfer to withstand the intestinal juice; (2) reliable viability in the distal part of the flap, especially when an extended length of the flap is required; (3) more length of stable tissue for two-layered, tension-free anastomosis at the junction of skin and gastrointestinal mucosa to prevent leakage; and (4) the flap can be placed in the substernal position to meet the aesthetic requirement of young patients. The disadvantage was the staged operations. However, after prefabrication the transfer becomes safe and free of leakage. The overall morbidity is minimal. CONCLUSIONS In rare situations when skin flaps are used for esophageal reconstruction, prefabrication provides advantages over conventional one-stage methods, although it needs additional procedures. This method is a combination of conventional technique and microsurgery.

A modified free chimeric osteocutaneous fibular flap design for head and neck reconstruction: Experience on a series of 10 cases

We have previously described a modified chimeric fibular osteocutaneous flap design based on a combination of a traditional fibular flap and a peroneal artery perforator fasciocutaneous flap for mandible and adjacent soft tissue reconstruction. The purpose of this article is to share our experience with a larger case series utilizing this new technique for mandible and adjacent soft tissue reconstruction after cancer wide excision surgery and a more detailed description on these flaps harvesting procedures.

Economy of donor site incisions: multiple free flaps of the subscapular family for extensive extremity wounds and bilateral foot defects.

One of the most important goals of modern microsurgical reconstruction is to decrease donor site morbidity as much as possible. With free flaps for lower limb reconstruction, economy of donor sites was designed and performed in 39 patients. Among these 39 patients, 17 had multiple flaps raised from a single incision for reconstruction of multiple defects in one or both lower extremities. Microvascular reconstruction of multiple defects is a challenging problem, particularly if it is to be performed simultaneously. The patients were followed for more than 3 years. Immediate complications and long-term disabilities were analyzed. From the data we conclude that this method has the following advantages: (1) economy of donor site incisions, (2) less harvest time, and (3) availability of any composite tissue for transfer. Donor site morbidity can be reduced by good planning, careful dissection, meticulous hemostasis, and adequate postoperative management.

Chronic osteomyelitis of the spine managed with a free flap of latissimus dorsi : A case report

Study Design A patient with intractable spinal osteomyelitis who underwent surgery 12 times with persistent exposed bone is presented. Objectives To demonstrate the effectiveness of free‐flap grafting for managing difficult spinal osteomyelitis wounds. Summary of Background Data Conventional procedures can usually achieve wound closure, but they may not work for advanced cases. Methods A free latissimus dorsi flap was transferred for reconstruction. The muscle component was used to obliterate the dead space and cover the exposed bone, and the skin component was used for tension‐free closure of the wound. Results The wound healed dramatically. There was no recurrence of infection at 2‐year follow‐up evaluation. Conclusions For an intractable spinal osteomyelitis wound, a free flap should be considered, although the surgery is difficult. Technical precautions in performing this operation are given.

Reconstruction for sternal osteomyelitis at the lower third of sternum.

BACKGROUND Sternal wound infection causes considerable morbidity and mortality for open-heart patients. Treatment of the wounds at the upper two-thirds is easier with pectoralis major muscle or other flaps. However, there would be more problems with the lower one-third sternal wounds. METHODS From 1983 to 2007, 32 patients of osteomyelitis involving the lower sternum were treated with one of the following methods: (1) Latissimus dorsi with fasciocutaneous extension flap (2) Tri-pedicled pectoralis major musculocutaneous flap (3) Pectoralis major muscle with rectus abdominis muscle flap (4) Pectoralis major muscle with omentum flap (5) Free vastus lateralis muscle flap and skin grafting RESULTS The viability of these flaps was good except for one of the five patients with pectoralis major-rectus abdominis muscle. One of the patients from the free vastus lateralis muscle group died of heart failure 6 weeks after surgery, but the coverage of sternal wound was successful. No recurrent sternal infection was found. CONCLUSIONS For coverage of sternal wounds, the transferred tissue must have optimal blood supply in order to overcome the infection. According to the descending degree of ease, the ladder of reconstruction is from (1) to (5), depending on the relative length of the sternal wound and the arc of rotation of these flaps. In pectoralis major with rectus abdominis flap group, it is suggested that the upper sternal wound be covered with pectoralis major muscle but lower third sternal wounds with omentum instead of rectus abdominis muscle.

Nosocomial infection of Aeromonas hydrophila presenting as necrotizing fasciitis.

Aeromonas hydrophila is infrequently reported as a causative organism of necrotizing fasciitis. We report a case of necrotizing fasciitis due to A. hydrophila in a 44-year-old man with Marfan syndrome who underwent valve replacement surgery twice. He was admitted due to a 2-day history of fever. The fever was attributed to hepatitis, and ingestion of herbal medication was suspected to be the cause. The fever relapsed on the 28th day of hospitalization with rapidly progressive erythematous patches on the bilateral lower extremities. Septic shock developed within a few hours, and 2 small diagnostic incisions on the skin lesions suggested necrotizing fasciitis. Surgical exploration further revealed extensive necrosis of the subcutaneous tissue and fascia, but the muscle was spared. Blood cultures and cultures of the debrided tissue all yielded A. hydrophila. Pathological examination showed necrosis and degeneration of the soft tissue. Although appropriately managed with broad-spectrum antibiotics, fasciotomies and debridement, the patients condition deteriorated rapidly and resulted in death 11 hours after the surgery. This case indicates that A. hydrophila can be a causative organism of nosocomial necrotizing fasciitis.