Chemical contamination of the East River (Dongjiang) and its implication on sustainable development in the Pearl River Delta.

A recent survey reveals that water quality and river sediments of Dongjiang (the East River) have been mildly contaminated by heavy metals and organic chemicals, such as copper, lead, PCBs, PAHs and HCHs. According to photogrammertic surveys, the sources of contamination are closely related to human activities, such as domestic and industrial discharges, agricultural chemical applications and soil erosion due to deforestation. The level of water and sediment contamination is most serious at the mid-river section near the urban of Weizhou. Due to natural dilution and diffusion, the levels of contamination are slightly decreased at the medium low section of the River near Qiaotou and Matan. Nevertheless, the levels of contamination increase again in the lower river section near Shenzhen, which is a highly developed economic zone. Since Dongjiang is the major source of potable water supply for Hong Kong (nearly 80% of potable water of Hong Kong is abstracted from Dongjiang) and the other parts of the Pearl River Delta (PRD), such organic and inorganic pollution merit concern. Ironically, most of the industrial and commercial activities in the watershed of Dongjiang are business investments of Hong Kong citizens. Cross-border environmental efforts should be enhanced with collaboration of different jurisdictions to achieve targets of regional sustainability.

Learning curve of microvascular venous anastomosis: a never ending struggle?

In this study, a simple protocol based on the rat femoral venous anastomosis was established to provide a quantitative representation of the progress. The learning curve is based on the patency rate in each consecutive group of five anastomoses. Two groups of surgeons were observed. The inexperienced group encountered a tough time in the first 25 anastomoses. However, the progress was fast and is represented by the steep slope of the curve. A plateau was reached whereby the avearge patency rate matches that of the experienced group. As expected, there was no learning curve for the experienced group. Despite every effort to attempt to maintain a perfect 100% patency on this model, the best achievable patency was only 88%. The results and its implication are discussed.

Compartment syndrome of the forearm as the initial symptom of systemic Vibrio vulnificus infection.

Sepsis, cellulitis, and necrotizing fasciitis rarely have been described as causes of compartment syndrome. We report a case in which forearm compartment syndrome presented as the initial symptom of systemic infection. Vibrio vulnificus, the etiologic pathogen of the compartment syndrome, was isolated from wound and blood cultures. The patient was treated with systemic antibiotic treatment and multiple forearm fasciotomies. The infectious process progressed rapidly, however and due to underlying liver insufficiency, the patient died of hepatorenal syndrome. This case illustrates the nature of V. vulnificus infections, which are characterized by shellfish transmission, predilection for soft tissue seeding, and a fulminant course in the compromised host.

Calf augmentation using free TRAM flap.

Augmentation of the calf for correction of contour deformities has been most frequently performed utilizing silicone implants. Results of such implants have often been unsatisfactory. We report the case of a 27-year-old woman who chose the use of a transverse rectus abdominis myocutaneous (TRAM) free flap for correction of a left calf contour deformity from childhood polio. This is the first report of calf augmentation with the use of a TRAM free flap and excellent results were obtained.

Functional assessment of the shoulder following latissimus dorsi muscle donation in the handicapped.

The latissimus dorsi muscle, one of the largest muscles in the human body, has gained widespread popularity in microsurgical reconstruction. Because the latissimus serves to adduct and medially rotate the upper extremity, caution in its use has been advocated in handicapped and non-ambulatory patients, although a paucity of information exists in the literature. The purpose of this reported project was to determine whether the loss of the latissimus dorsi could be documented objectively or subjectively, either in the preoperative condition or post-harvesting in the handicapped patients. Two paraplegic patients were studied. Results indicate a lack of objective functional deficit; this includes both the nerve-blocked state and the postoperative condition. In addition, both patients failed to demonstrate the need to change any activities of daily living. This evidence suggests that, although careful decisions must be made on a case-by-case basis, the use of the latissimus dorsi muscle is not necessarily contraindicated in this group of patients.

Z-plasty closure of the donor defect of the radial forearm free flap.

The radial forearm is a popular free flap site for reconstruction of head and neck defects, because of its abundant, pliable, skin component and an available, extended, vascular pedicle. In addition, vascularized composite flaps, including a segment of radius, can be designed for skeletal stabilization. The donor-site defect can involve various complications, including loss of skin graft, unsatisfactory appearance, numbness, and radial fracture. Recent advances in reducing donor-site defect problems have included the use of rotation skin flaps, local muscle rotation, and soft-tissue expansion; however, each of these has its own limitations. Two cases are presented in which radial forearm donor site defects, measuring less than 4 cm x6 cm, were primarily closed successfully with z-plasties based on the longitudinal skin incision. Each patient has regained preoperative mobility, and prompt primary healing was achieved without complications.

Serratus anterior-rib composite flap: anatomic studies and clinical application to hand reconstruction.

Because of its relative ease of dissection, increased length of the vascular pedicle, and excellent diameter for anastomosis, the serratus anterior-rib composite flap has been used to reconstruct bony and soft-tissue defects in the face and lower extremities. However, no data are available on optimal rib level or harvest location. The authors report the results of the vascular anatomy of this flap in 6 fresh cadavers and 2 clinical patients using this flap to reconstruct a defect in the hand. Arteriograms were performed through the thoracodorsal artery, and microscopic dissections were done at the rib periosteum. The sixth through the ninth ribs showed consistent filling of their respective intercostal vessels. The rib segments near the anterior axillary line had the most abundant communicating vessels between the serratus and the periosteum. In two patients, the serratus-rib composite free flap provided excellent bone and muscle length for reconstructing the first metacarpal defect.

Cross-facial vein grafting in complicated flap reconstructions of the face and mandible.

Microvascular flap reconstructions of facial and mandibular defects are achieving increasingly widespread application and, as a result, more patients are considered for such procedures after large tumors, congenital abnormalities, previous surgery (including failed and successful microsurgical procedures) and radiation have compromised potential recipient vessels on the side of the defect. In three such cases, contralateral facial vessels with vein grafts have been used to provide flap-recipient vessels. Each flap was successful. Cross-facial vein grafting is a relatively simple solution for utilizing undamaged vessels as recipient pedicles in complicated flap reconstructions of the face and mandible.

Power Doppler imaging in preoperative planning and postoperative monitoring of muscle flaps.

PURPOSE: We assessed the utility of power Doppler imaging (PDI) in preoperative planning and postoperative evaluation of microvascular tissue transfers. METHODS: Twenty-five PDI studies were performed on 23 patients using a 5-10-MHz linear-array transducer. Thirteen patients were assessed preoperatively for patency of the desired donor vessel; 8 of them had surgical scars overlying the desired vascular territory. Twelve patients (including 2 from the first group) were evaluated postoperatively for patency of the vascular anastomoses and adequacy of the blood supply to the transferred tissue. RESULTS: Twelve of the 13 patients assessed preoperatively had successful flap transfers. Four of the 8 patients with scars over the desired vascular territories had absent or aberrant arteries, necessitating a change in the operative plan. None of these patients had operative complications. Eight of the 12 patients scanned postoperatively had patent anastomoses. In 2 of these patients, impending surgery was averted when the adequacy of the tissue blood supply was established with PDI. In 4 patients, PDI showed arterial or venous compromise, which was confirmed at surgery. CONCLUSIONS: PDI is a useful technique in microsurgical tissue transfer for assessing the patency of desired donor vessels preoperatively and for postoperative evaluation of blood supply.

Uncomplicated pregnancy following total bilateral rectus harvest: a case report.

Muscle-sparing rectus abdominis muscle harvest has been advocated to preserve abdominal wall integrity and to reduce postoperative complications and functional loss. In previous cases of pregnancy following single and bilateral rectus muscle harvest, muscle-sparing techniques were used to fortify the abdominal wall. We report a case of uncomplicated gestation and delivery following total bilateral rectus muscle harvest. While abdominal wall strength is greatly affected by rectus harvest, the fascial and tendonous components of the abdominal wall contribute substantial static integrity and elasticity. Careful repair of the donor site makes complete rectus muscle harvest an option even for women contemplating pregnancy.