Is Immediate Lymphatic Reconstruction on Breast Cancer Patients Oncologically Safe? A Preliminary Study.

Background: In breast cancer patients receiving axillary lymph node dissection (ALND), immediate lymphatic reconstruction (ILR) with lymphovenous anastomosis is an emerging technique for reducing the risk of arm lymphedema. However, the oncologic safety of surgically diverting lymphatic ducts directly into venules in a node-positive axilla is still a concern of inadvertently inducing metastasis of remaining cancer cells. This study aimed to assess the oncologic safety of ILR. Methods: From January 2020 to January 2022, 95 breast cancer patients received ALND, and 45 of them also received ILR. Patients with recurrent cancer, with follow-up less than 12 months, and with missed data were excluded. Variables were compared between ILR and non-ILR groups, and the outcome of interest was the rate of distant recurrence after follow-up for at least 1 year. Results: Thirty-four patients in the ILR group and 32 patients in the non-ILR group fulfilled the inclusion criteria for analysis. No statistically significant difference was noted between groups in terms of age, body mass index, type of breast surgery, pathologic cancer staging, histologic type and grade of breast cancer, molecular subtypes, frequency of axillary lymph node metastasis, or adjuvant therapy. For the patients receiving follow-up for at least 1 year, no statistically significant difference was found in terms of distant recurrence rates between ILR and non-ILR groups (P = 0.44). Conclusion: For breast cancer patients receiving ALND, ILR with lymphovenous anastomosis is oncologically safe, within an average follow-up period of 21 months.

The effect of immediate lymphatic reconstruction on the post-operative drain output after axillary lymph node dissection for breast cancer: A retrospective comparative study.

INTRODUCTION: Axillary lymph node dissection (ALND) for breast cancer has been considered to be associated with a variety of complications, such as excessive postoperative wound drainage, prolonged drain placement, or seroma formation in the short term, or arm lymphedema in the long run. Immediate lymphedema reconstruction (ILR) has been proposed to reduce the occurrence of arm lymphedema by anastomosing the transected arm lymphatics to nearby branches of the axillary vein immediately after ALND. This study aims to demonstrate that ILR can also reduce the postoperative drainage amount. PATIENTS AND METHODS: Between April 2020 and January 2022, a total of 76 breast cancer patients receiving ALND were reviewed. Forty four of them also received ILR immediately after ALND. The assignment of ILR surgery was non-random, based on patients' willingness and plastic surgeons' availability. The lymphatic vessels in the axillary wound were anastomosed with nearby terminal branches of the axillary vein under surgical microscope. Patients' characteristics, including age, body mass index (BMI), neoadjuvant therapy, type of breast surgery, the occurrence of seroma formation, number of removed lymph nodes, number of positive nodes, and the drainage amount from the operative wounds were compared between ILR and non-ILR groups. RESULTS: No statistically significant difference was noted between groups in terms of age (56.5 ± 9.8 vs. 60.9 ± 10.7, p = .09), BMI (22.6 ± 3.7 vs. 23.7 ± 3.8, p = .27), type of breast surgery (p = .32), the occurrence of seroma formation (p = 1.0), the likelihood of receiving neoadjuvant therapy (p = .12), number of lymph nodes removed (17.5 ± 7.6 vs. 17.4 ± 8.3, p = .96), or number of positive nodes on final pathology (3.7 ± 5.4 vs. 4.8 ± 8.5, p = .53) except the ILR group had statistically significantly less drainage amount than non-ILR group (39.3 ± 2.6 vs. 48.3 ± 3.7, p = .046). CONCLUSION: For breast cancer patients receiving ALND, the immediate lymphatic reconstruction can reduce the postoperative drainage amount from the operative wound.

The relationships between routine admission blood tests and burn size, and length of stay in intensive care unit.

BACKGROUND: Although blood test is a routine in major burns, its relationship with burn size and intensive care unit length of stay (ICULOS) remains undetermined. We investigated the feasibility of using these tests as a reference for definite diagnosis of major burn size, burn size >20% of the total body surface area (TBSA), and their relationships with ICULOS. METHODS: Data of routine laboratory blood tests within 24 h after burns (n = 73) were collected retrospectively. Correlation tests and regression analyses were performed. RESULTS: Burns ≥20 TBSA had higher incidences of leucocytosis, hypoalbuminaemia, elevated haemoglobin (Hb), and elevated haematocrit (Hct). Burn size was correlated negatively with albumin but positively with Hb, Hct, and white blood cell (WBC) count. For each unit increase in blood urea nitrogen (BUN)/creatinine (Cr), there was an increase of 1.2 days of ICULOS in females, while in males, there was a 6.7 day increase for every unit increase in Hb and a 3.1 day increase for each unit increase in BUN. A female model including Hb and WBC was derived, discriminating burns ≥20 TBSA with sensitivity and specificity 0.94 and 1.0 respectively, and area under the receiver operating characteristic curve (AUROC) 0.96 (95% CI 0.91-1.00). The male model had sensitivity 0.96, specificity 1.0, and AUROC 0.96 (95% CI 0.89-1.00). CONCLUSION: Admission Hb and WBC could be used as a reference for definite diagnosis of major burn size, especially in borderline cases. BUN/Cr in females, and Hb and BUN in males, were related to ICULOS.

Does early bloodstream infection pose a significant risk of in-hospital mortality in adults with burns?

BACKGROUD/PURPOSE: Bloodstream infections (BSI) are common in patients with major burns, but its effect on mortality remains controversial. This study was aimed to investigate if BSI is significant risk factor of mortality? METHODS: This is a retrospective chart review study included 266 adult patients admitted to our burn center from 2000 to 2019. Age, sex, inhalation injuries, total burn surface area (TBSA), duration of stay in intensive care unit, BSI and mortality were variables studied. Fisher exact test, Mann-Whitney test and logistic regression was used for statistical analysis. RESULTS: There were 234 survivors and 32 non-survivors. Male was predominant. The overall incidence of BSI was 18.8%, and the overall crude mortality was 12%. Burns ≥30% TBSA and BSI were significant risk factors. A predictive function based on30% TBSA and BSI within 14 days after the onset of burns (BSI-14) was derived. The function has a sensitivity of 0.97, specificity of 0.42 and achieved a maximum Youden Index at functional value ≥0.05727. The mortality probability of BSI-14 in burns ≥30% TBSA was 40.8%. CONCLUSIONS: BSI and burns ≥30% TBSA were significant risk factors of mortality. Early detection of BSI-14 is critical in burn care as its probability of mortality can be as high as 40% in patients ≥30% TBSA of burns. To reduce the risk of mortality, early in ventilator withdrawal, invasive lines and tubes removal, and early grafting should be emphasized besides infection control and appropriate use of antibiotics.

Molecular diagnosis and therapy for cutaneous leishmaniasis of a returned traveler from Mexico.

Leishmaniasis is prevalent in Southern Europe, the Middle East, India, Africa, and Central and South America. Cutaneous leishmaniasis may spontaneously heal over time without treatment; however, risk of visceral dissemination and the impact of cosmetic defect are important concerns. We report a Case of cutaneous leishmaniasis in a patient who ever traveled to Mexico before the onset of a deteriorating wound around the swollen left eyebrow. A diagnosis of infection with Leishmania mexicana was made based on histopathological examination and molecular identification. Systemic treatment with liposomal amphotericin B and ketoconazole were administered with gradual healing of the lesion. Also, this traveler case implicates that the spread of endemic parasitic diseases may be a concealed risk on the public health for Taiwan underlying globalization.

The Wound Microbiology and the Outcomes of the Systemic Antibiotic Prophylaxis in a Mass Burn Casualty Incident.

This paper describes the wound microbiology and outcome of using systemic antibiotic prophylaxis (SAP) in mass burn casualties (MBC). The charts of 31 patients (mean age: 21 years, mean burn area: 42% of the total body surface area) injured in a dust explosion were reviewed for 1 month after the burn. Polymicrobial and rare pathogen wound infections (Acinetobacter junii, Aeromonas sobri, et al) were common in MBC due to sterility breech. Following the use of SAP for 2 to 14 days after admission, there was a reduction in wound infection rate from 45% at week 1 postburn to 10% at week 4. In addition, no blood stream infection occurred in the first week after the burns. Multidrug-resistant Acinetobacter baumannii, Klebsiella pneumoniae, and Candida albicans were the top three wound pathogens cultured. Multidrug-resistant microorganism infections were found in 39% of the patients, and the odds ratios for the these infections in burn patients with more than ≥40% total body surface area and in patients receiving two or more classes of antibiotics were 41.7 (95% confidence interval [CI] = 2.1-810.7, P = .01) and 9.9 (95% CI= 1.0-92.7, P = .04), respectively. Although SAP did not prevent wound or blood stream infections, no mortality occurred in our patients. A randomized controlled study is needed to investigate the impact of SAP on burn mortality in MBC.

Risk Factors for Multidrug-Resistant Acinetobacter baumannii Infections in a Mass Burn Casualty Incident.

They investigated the risk factors of multidrug-resistant Acinetobacter baumannii infections in 33 burn patients in a mass burn casualty. The independent variables included sex, burn size, vancomycin, ampicillin/sulbactam, cefazolin, meropenem, third-/fourth-generation cephalosporin, the number of classes of antibiotic used, and the number of days of antibiotic use. Multidrug-resistant A. baumannii infection was the outcome variable. Logistic regressions and structural equation model were used for statistical analysis. The average age was 21.7 years (range, 17-32 years; M = 11 [33%], F = 22 [67%]; mean burn area, 42% of the total body surface area; study period, June 28, 2015 to July 31, 2015). The incidence of infection was 39% (n = 13/33). For every percent increase in burn size, the odds of developing A. baumannii infections increased by 1.1 (P < .05). Similarly, the odds increased by 2.5 in every number increase in the classes of antibiotic used, by 1.2 in everyday increase in the days of antibiotic used, and by 12 in patients treated with vancomycin (P < .05). The correlations of these risk factors were demonstrated in a hypothetical structural equation model (P-value of chi-squared test > .05 and root mean square error of approximation < 0.05) in which burn size was the fundamental risk factor of multidrug-resistant A. baumannii infections. The model did not predict the emergence of multidrug-resistant A. baumannii infections. Conclusively, the risks of multidrug-resistant A. baumannii infections in burns are correlated with burn size, the number of classes of antibiotic used, the number of days of antibiotic use, and the prior use of vancomycin.

Response of a local hospital to a burn disaster: Contributory factors leading to zero mortality outcomes.

OBJECTIVE: To investigate the outcomes of a local healthcare system in managing a burn mass casualty incident (BMCI). METHODS: Thirty-three victims admitted to the National Taiwan University Hospital within 96h of the explosion were included in the study. Data were recorded on: patient demographics, Baux score, laboratory data, management response, treatment strategies, and outcomes. Case notes from June 27, 2015 to November 2015 were reviewed with a focus on fluid resuscitation, ventilation support, nutrition, infection control, sepsis treatment, and wound closure plan. RESULTS: Female predominance (mean age: 21.7 years) and lower extremity circumferential flame burns were the characteristics of the burn injury. The mean Baux score was 70±18. The mean burn area was 42% of the total body surface area (TBSA). A total of 79% patients arrived at the hospital within 24h of sustaining injuries. Intensive care unit (ICU) admission criteria were modified to accommodate patients with 40% TBSA of burns, facilities were expanded from 4 ICU beds to 18 beds, and new staff was recruited. A total of 36% patients (n=12/33, 62±13 TBSA of burns) required fluid resuscitation. The mean volume of Lactate Ringer administered in the first 24h of burns was 3.34±2.18ml/kg/%TBSA, while the mean volume of fresh frozen plasma administered was 0.60±0.63ml/kg/h. Forty-two percent patients were intubated on the day of admission, and 71% of the intubated patients had inhalation injuries that were confirmed by diagnostic bronchoscopy. The mean intubation period was 17±9 days. The incidence of pulmonary edema was 58% (n=7/12), possibly due to sub-optimal monitoring. Of these, 57% (n=4/7) patients progressed to adult respiratory distress syndrome, but were successfully treated with early strict fluid restriction, systemic antibiotics, ventilation support, and bronchial lavage. A total of 94% patients received grafting. The mean grafted area was 4432.3±3891cm2. Tube feeding was provided to patients with burns >40% TBSA. All patients tolerated gastric tube feeding without conversion to duodenal switch. On admission, all patients received prophylactic antibiotics. Septic shock was noted in 12 patients, but no mortality occurred. The mean hospital stay was 1.5 days per percent burn. CONCLUSIONS: This article highlights the value of precise triage, traffic control, and effective resource allocation in treating a BMCI. Effective supporting systems for facility expansion, staff recruitment, medical supplies and clear-cut treatment strategies for severely burned patients are contributory factors leading to zero mortalities in our series, in addition to young age and minimal inhalation injuries. The need for reevaluation of the safety of cornstarch powder in festival activities is clear.

[The Treatment of Major Burn Injuries].

Major burn injuries constitute a systemic disease. In addition to completely understanding the mechanisms of wound healing, precise burn depth and area assessment is critical to the successful management of burn injuries. The recent advancements in post-burn fluid resuscitation, tangential burn excision and grafting, effective enteral tube feeding, and aggressive sepsis treatment have helped greatly increase the survival rates for major burn injuries. However, the restricted joint motion that results from hypertrophic scar contracture remains the main challenge facing burn survivors. In conclusion, as the course of the treatment and rehabilitation is prolonged and multifaceted, a complete treatment plan is always necessary in addition to teamwork among physicians, nurses, social workers, physical therapists, and psychologists. Finally, social return is the final goal of treatment and may be achieved only through mutual support and understanding among the members of the burn treatment and rehabilitation team.

An unusual electrical burn caused by alkaline batteries.

Electrical burns caused by low-voltage batteries are rarely reported. We recently encountered a male patient who suffered from a superficial second-degree burn over his left elbow and back. The total body surface area of the burn was estimated to be 6%. After interviewing the patient, the cause was suspected to be related to the explosion of a music player on the left-side of his waist, carried on his belt while he was painting a bathroom wall. Elevated creatine kinase levels and hematuria indicated rhabdomyolysis and suggested an electrical burn. Initial treatment was done in the burn intensive care unit with fluid challenge and wound care. The creatine kinase level decreased gradually and the hematuria was gone after 4 days in the intensive care unit. He was then transferred to the general ward for further wound management and discharged from our burn center after a total of 11 days without surgical intervention.

Surgical treatment of distal digit amputation: success in distal digit replantation is not dependent on venous anastomosis.

BACKGROUND: Although digit amputation at or distal to the distal interphalangeal joint is a common injury, it remains a challenging problem to restore digital length and pulp because of the lack of healthy vessels and the absence of proper vascular size for reanastomosis. The purpose of the present study was to review the authors' clinical experience with distal digital replantation and to test the hypothesis that success in distal digit replantation is not dependent on venous anastomosis. METHODS: Twenty-eight patients with 31 complete distal digit amputations were included in the study. Data regarding patient demographic, replantation technique, and surgical outcome were analyzed. RESULTS: Sixteen digits were replanted with arterial and venous anastomoses (group A). Eleven digits were replanted with only arterial anastomosis (group B). Composite grafting was performed in four digits without vascular anastomosis (group C). The success rates in group A and group B were 81.3 and 81.8 percent, respectively. None of the composite grafts survived. Fisher's exact test was used for statistical analysis. Although group C has the lowest survival rate (p < 0.05), the differences between the survival rates in group A and group B (p > 0.05) were insignificant. CONCLUSIONS: The overall success rate of distal digit replantations in the authors' series was 81 percent, and there were no differences in the survival rates between replantations with and without venous anastomosis. Finally, the authors conclude that success in distal digit replantation is not dependent on venous anastomosis and suggest that replantation should be encouraged in complete distal digital amputation, even without venous anastomosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Reconstruction for osteoradionecrosis of the mandible: superiority of free iliac bone flap to fibula flap in postoperative infection and healing.

BACKGROUND: Osteoradionecrosis (ORN) of the mandible is not an uncommon complication after radiotherapy for head and neck cancers. Although definitive treatment has been confirmed as radical excision of the necrotic bone with simultaneous vascularized osteocutaneous flap reconstruction, it remains a unique challenge. In this study, we compare our results of reconstruction with free iliac and fibula flaps in flap survival, bony union, and postoperative complications. PATIENTS AND METHODS: From 1986 to 2011, there were 153 mandibular ORN cases in our center that were treated with radical resection of the necrotic bone and reconstruction with either vascularized iliac (n=108) or fibula flaps (n=45). Data collected for analysis included patient demographics, flap survival rate, postoperative infection rate, nonunion/malunion rate, mean hospital stay, and antibiotics use. RESULTS: All patients healed eventually without recurrence of ORN. However, we observed difference in the complication rate between the iliac flap group and fibula flap group. In the group with iliac flap reconstruction, patients required less days of hospital stay for intravenous antibiotics treatment postoperatively. The average days required for intravenous antibiotics in the iliac flap group were 10.46 (2.28) versus 16.09 (3.88) days in the fibula group (P<0.01). In the group with fibula flap reconstruction, 9 (20.0%) patients had subsequent neck infection due to healing problem, compared to 8 (7.4%) patients in the iliac flap group (P=0.04). In the iliac flap group, the nonunion and malunion rates were 4.6% and 2.8% respectively; whereas in the fibula group, the rates were 15.5% and 6.6%, respectively (P=0.04 and 0.36, respectively). CONCLUSIONS: For ORN patients, vascularized iliac bone flap provides more reliable results compared to fibula flap. The merits of vascularized iliac flap include the following: (1) its natural curve mimics the shape of mandible and does not need osteotomy; (2) it offers more volume of bone that matches better to the native mandible to allow later osteointegration as well as faster bony union, due to the nature of being a membranous bone; and (3) it carries more abundant soft tissue to obliterate possible dead space. The only disadvantages are short pedicle and requiring special management of skin paddle, which can be overcome by training in microsurgery.

Is artificial dermis an effective tool in the treatment of tendon-exposed wounds?

As flap surgery remains the main technique to close wounds with tendon exposure, the application of artificial dermis in these complex soft tissue wounds is seldom reported. The purpose of this article is to review our experiences in the treatment of tendon-exposed wounds with artificial dermis. This retrospective study included 23 patients with 33 tendon-exposed wounds treated with artificial dermis from 2004 to 2009. Data including patient demographics, wound type, duration from artificial dermis implantation to split thickness skin grafting, surgical complications, and clinical outcome were obtained by chart review. Successful treatment was defined as the formation of golden-yellow neodermis followed by successful split thickness skin grafting. Among the 33 tendon-exposed wounds, 11 were secondary to chronic ulcers, 16 to acute wounds, and 6 to surgical wounds after hypertrophic scar excision. The mean patient age was 49 years. The overall success rate with the artificial dermis technique was 82%, including 63% in the chronic ulcer group, 88% in the acute wounds, and 100% in the surgical wounds. In the success group, 11% of the wounds required repeated artificial dermis implantations. Within the failure group, two wounds were closed by below knee amputation, two by local flap surgery, and two were allowed spontaneous healing as a result of graft failure. We have demonstrated an overall success rate of 82% for tendon-exposed wound closure by using artificial dermis. The outcome was better in surgical and acute wounds than in chronic wounds.

Free and pedicled appendix transfer for various reconstructive procedures.

INTRODUCTION: The appendix has a constant vascular anatomy and provides a small lumen that always maintains its patency because of mucosal secretion and motility; thus, it serves as an ideal conduit structurally. The appendix has been used in urologic surgeries as a pedicled flap and as a free flap in isolated case reports for the reconstruction of the urethra. However, this study proposes more extended applications of the appendix in different kinds of reconstruction. METHODS: From 2002 to 2011, 11 patients were included in this study retrospectively. Of these cases, 8 were transferred as free flaps, whereas the other 3 were pedicle flaps. Among the 8 free appendix transfers (A and B), 5 of them were used for voice reconstruction by creating a tracheoesophageal fistula; the other 3 were transferred to reconstruct the male urethra. Among the 3 pedicled appendix transfer, 2 were used for reconstruction of cervix and vagina, whereas the other was used for reconstruction of esophagus and voice tube simultaneously after ablation of cancers in the hypopharynx and esophagus. RESULTS: All cases showed successful results not only structurally but also functionally. As for voice reconstruction, the appendix serves as an autologous fistula between the trachea and the esophagus with minimal complications and no aspirations. The intelligibility and loudness were fair to excellent, whereas fluency required persistent training and practice.For patients who underwent urethral reconstruction, their micturition was smooth with ease postoperatively. Two of the patients also received penile reconstruction with fibula osteocutaneous flap simultaneously during the urethral reconstruction.As for reconstruction of cervix and vagina, pedicled appendix-cecum-colon-complex is a great option offering long-term patency with an expandable diameter up to 2.5 cm. CONCLUSIONS: Appendix has a reliable vascularity and a unique structure for reconstruction of conduit-like organs, and combining its adjacent bowel segments, including ileum, cecum, and colon, during tissue transfer not only increases its length but provides more applications and possibilities for reconstruction of different parts of the body. Removal of the appendix carries minimal morbidity. Our study proved the applicability and reliability of free and pedicled appendix transfer.

The treatment of bone exposure in burns by using artificial dermis.

BACKGROUND: The treatment of bone-exposed wounds with artificial dermis is not widely accepted in burn patients because of uncertain clinical results. This article aimed to review our clinical experience with this technique. METHODS: We implanted artificial dermis in 11 bone-exposed burns. Implantation was directly performed on bones with periosteum, whereas bones without periosteum were trephinated or burred before implantation. All wounds were closed by secondary skin grafting. RESULTS: The mean patient age was 49 years. Lower extremity is the most common site of bone exposure. The mean bone exposed area was 55.6 cm, whereas the mean Integra-implanted area was 86.7 cm. The overall implant take rate was 91%, and the skin grafting success rate was 80%. No secondary breakdown was noted after a 2-year follow-up. CONCLUSIONS: This study confirms that artificial dermis can be an alternative treatment tool for burns with exposed bones, especially in patients with limited donor sites.

Prognostic significance of left ventricular diastolic function in burn patients.

Severe inflammation leads to cardiac diastolic dysfunction, an independent prognostic marker for the mortality of critically ill patients. We investigated the possible molecular mechanism from inflammatory cytokines (tumor necrosis factor α [TNF-α] and interleukin 6 [IL-6]) causing left ventricular (LV) diastolic dysfunction in critically burned patients. We consecutively enrolled 56 critically burned patients who were admitted to the intensive care unit and performed transthoracic echocardiography to evaluate LV diastolic function. Sarcoplasmic reticulum Ca²âº-ATPase 2 (SERCA2) gene expression in HL-1 cardiomyocytes was used as a molecular phenotype of diastolic heart failure. Soluble plasma levels of TNF-α and IL-6 were measured in all subjects. The effect of serum from the burned patients on SERCA2 gene expression of HL-1 cardiomyocytes was investigated. The total body surface area of burned patients was proportional to serum level of IL-6 and TNF-α (P < 0.001 for each). Significant correlations were found for TNF-α and decelerating time, E/A, and E/Em (r² = 0.59, 0.45, and 0.52; P <0.001 for each) and for IL-6 and decelerating time, E/A, and E/Em (r² = 0.63, 0.60, and 0.62; P < 0.001 for each). Diastolic function improved significantly in association with decrease in cytokines after burned patients were transferred to general ward (P < 0.001). Tumor necrosis factor α, IL-6, and sera from critically burned patients downregulated the expression of the SERCA2 gene in HL-1 cardiomyocytes. There was a significant correlation between LV diastolic dysfunction and in-hospital mortality in critically burned patients (hazard ratio, 3.92; P = 0.034) after risk factors were adjusted. Inflammatory cytokines may be associated with cardiac diastolic, which could be an independent prognostic factor in burn patients. Novel therapeutic strategies may be applied in critically burned patients with LV diastolic dysfunction by modulating inflammatory reactions.

Serum bicarbonate as a marker to predict mortality in toxic epidermal necrolysis.

BACKGROUND: Toxic epidermal necrolysis (TEN) is a rare life-threatening disorder characterized by extensive epidermal necrolysis. Its mortality which varies from 20% to 60% is related to risk factors such as age, extent of epidermal detachment, and base deficit. OBJECTIVES: The purpose of this study is to investigate the risk factors of mortality in our patients with TEN. PATIENTS AND METHODS: From the year 2000 to 2006, the patients with TEN admitted to the National Taiwan University Hospital Burn Center were studied retrospectively using chart review. Eleven potential risk factors including age, gender, underlying disease, malignancy, extent of epidermal detachment, tachycardia, serum urea, glucose, base deficit, leucopenia, and intravenous infusion of immunoglobulin (IVIG) were analyzed. Patients were grouped into survivors (n » 11) and nonsurvivors (n » 5) after intensive care treatment. Logistic regression was used in multivariate analysis for identifying important predictors of mortality. RESULTS: The mean age of the patients with TEN was 58 years, while the mean total body surface area of epidermal necrolysis was 66.3%. The overall mortality rate was 31.3%. Among the potential risk factors, only serum bicarbonate <20 mmol/L was found to have significant association with mortality (P » .0128) in our patients with TEN. The odds of mortality in the patients with TEN having serum bicarbonate <20 mmol/L was 40 times higher than those without. CONCLUSION: This study has shown that serum bicarbonate <20 mmol/L is the most important risk factor of mortality in our patients with TEN and it may be used as a marker to predict hospital mortality.

Risk factors of tissue-expansion failure in burn-scar reconstruction.

BACKGROUND: Tissue expansion has become invaluable for burn-scar reconstruction. However, its use is hindered by the complications that often result in expansion failure. This study attempts to identify the risk factors of expansion failure in burn patients, as such factors have not been clearly defined. METHODS: This study included 62 tissue expansions in 37 burn patients from January 2001 to June 2009. Factors including patient's age, sex, co-morbidities, expander size, implantation site, volume injected at implantation, preinflation volume ratio (PVR=volume injected at implantation/expander size), final inflation volume ratio (FIVR=cumulative volume injected at completion of expansion/expander size) and expansion duration were analysed. Cases were allocated into success (n=53) and failure (n=9) groups. Logistic regression was used in multivariate analysis for identifying predictors of expansion failure. RESULTS: The mean age of the patients was 29.6 years. The male to female ratio was 1:1.4. Expansion complication and failure rates were 53% (n=33) and 14.5% (n=9), respectively. The risk factors statistically correlated to expansion failure (p<0.05) were age, expander size, PVR and implantation at lower limb. Expansion of lower limbs carried a risk of failure 43 times greater than other sites. CONCLUSION: We conclude that tissue expansion should be avoided in older patients and in lower limbs. The largest possible expander size and inflation at time of implantation should be used to lower the risk of expansion failure.

Pressure effects on the growth of human scar fibroblasts.

Although pressure therapy is the mainstay of treatment for hypertrophic scars, its actual mechanism remains unknown. An in vitro study was designed to investigate the effects of positive pressure on the growth of human scar-derived fibroblasts through its transforming growth factor beta1 (TGF-beta1) secretion. A pneumatic pressure system connecting to a cell culture chamber was designed. Six-well cultured plates with fibroblasts implanted were treated with different pressure settings. Cells were treated with constant pressure 20 mm Hg above atmosphere pressure (group A n = 18) or with 40 mm Hg above atmosphere pressure (group B n = 18) daily for nine successive days. Cells without pressure were treated as the control study (group C n = 6). Each experimental group was divided into daily pressure applied at 24 hours (n = 6), 18 hours (n = 6), and 12 hours (n = 6). Cell counting was performed on the 2nd, 4th, 7th, 9th, 11th, and 14th day after implantation. On day 4, the concentration of transforming growth factor beta1 was measured, and cell doubling time was calculated. Compared with the control group, there was a significant decrease in cell count and the concentration in the 18-hour and 24-hour 20 mm Hg or 40 mm Hg pressure treated group. The cell doubling time was significantly increased in the 24-hour 20 mm Hg or 40 mm Hg pressure treated groups, and the 18-hour 40 mm Hg pressure treated group. (P < .05) Pressure inhibits the growth and activity of human scar fibroblasts, and a higher pressure application can shorten the daily application period. There should be an optimal pressure level corresponding to a daily application period to achieve the most effective results on pressure therapy for scars.