新型脱细胞软骨基质三维多孔支架的制备

目的 探讨脱细胞软骨基质三维多孔支架的制备方法以及将其应用于关节软骨组织工程的可行性. 方法 取天然人软骨粉碎后,采用梯度离心法取100 nm～5μm软骨微丝,脱细胞处理后制备为质量体积比为3%的悬液,采用冷冻冻干法制备脱细胞软骨基质三维多孔支架.254nm紫外线和碳化二亚胺/N-羟基琥珀酰亚胺对支架进行交联.冷冻冻干后,对支架材料进行组织学及扫描电镜观察,测定支架孔径和孔隙率、吸水率,并采用MTT法分析支架浸提液毒性.分离培养犬BMSCs,用TGF-β1成软骨诱导后种植至支架,倒置显微镜、电镜观察细胞在支架上的生长、分化情况. 结果 组织学观察显示,三维多孔支架中无软骨细胞碎片残留,甲苯胺蓝染色、番红O染色、Ⅱ型胶原免疫组织化学染色均呈阳性.扫描电镜显示支架内孔洞相互连通,孔径为(155±34)μm,孔隙率为91.3%±2.0%,吸水率为2 451%±155%.MTT法显示不同浓度支架浸提液与对照DMEM培养液吸光度值比较,差异无统计学意义(P＞0.05),支架无细胞毒性.倒置显微镜观察,细胞在支架上黏附良好;扫描电镜下细胞在支架上均匀分布,细胞呈圆形或椭圆形,并有基质分泌. 结论 制备的脱细胞软骨基质三维多孔支架去细胞彻底,保留了软骨ECM主要成分,无毒,具备合适的孔径和孔隙率,生物相容性良好,是软骨组织工程良好的支架载体.     

胶原-透明质酸-硫酸软骨素复合三维支架体外构建组织工程软骨的实验研究

目的探讨以胶原(collagen,Col)透明质酸(hyaluronic acid,HA)硫酸软骨素(chondroitin sulfate,CS)为支架材料构建组织工程软骨的可行性.方法以乙基-(3-二甲基氨基丙基)碳化二亚胺盐酸盐为交联剂通过冷冻干燥的方法制备Col-HA-CS复合支架及单纯Col支架.通过扫描电镜、HE染色对Col-HA-CS复合支架材料形态进行观察.分离培养幼兔关节软骨细胞,将体外扩增的软骨细胞接种在两种支架上,通过组织学、扫描电镜观察软骨细胞在支架上的生长形态;通过生物化学功能检测细胞-支架复合物中DNA、糖胺聚糖(glycosaminoglycan,GAG)含量;RTPCR方法检测在Col HA CS复合支架上的软骨细胞ColⅡ的表达情况.结果软骨细胞在Col-HA-CS复合支架材料上增殖分化良好,并保持软骨细胞特异的分化ColⅡ表型,培养21 d后已有软骨样组织形成,出现软骨陷窝.DNA和GAG含量测定显示软骨细胞在复合支架上随时间增加逐渐扩增并分泌大量的GAG,含量明显高于单纯Col支架材料,差异有统计学意义(P＜0.05).结论 Col-HA-CS复合支架材料可为软骨细胞生长分化及组织形成提供一个良好的环境,在软骨组织工程的支架材料领域有较广泛的应用前景.     

壳聚糖与Ⅱ型胶原复合制作组织工程软骨支架及其性能研究

目的探讨采用壳聚糖与Ⅱ型胶原复合制作新型组织工程软骨三维多孔支架的方法,并对其理化性能进行检测. 方法将精制88%脱乙酰度壳聚糖溶于0.2 mol/L醋酸溶液制成2%溶液,高纯度猪Ⅱ型胶原溶于0.5 mol/L醋酸溶液制成1%溶液,两者按4∶1(重量比)充分搅拌混合,采用冷冻干燥法制成壳聚糖与Ⅱ型胶原复合支架.采用碳化二亚胺/ N-羟基琥珀酰亚胺对支架进行交联,力学测定比较支架交联前后的强度变化,扫描电镜观察其超微结构,于2、4、6和8周经溶菌酶体外降解实验测定其体外降解性. 结果制备的复合支架成形良好,交联后其力学强度明显增加.扫描电镜显示壳聚糖与Ⅱ型胶原成分在支架内分布均匀,支架内孔洞相互连通似海绵状,孔径100～250 μm.各时间段复合支架体外降解较单纯壳聚糖支架快. 结论壳聚糖与Ⅱ型胶原复合成功地制作成了三维多孔复合支架.其理化性能及体外降解测定,可以作为支架载体,应用于组织工程软骨的构建.     

胶原-透明质酸支架的制备及其与软骨细胞复合培养的实验研究

目的制备胶原-透明质酸支架,评价其与兔髁状突软骨细胞的生物相容性,探讨其应用于关节软骨组织工程的可行性。方法冷冻干燥法制备胶原-透明质酸复合多孔海绵支架材料,将其与碳化二亚胺[1-ethyl-3-（3-dimethyl aminopropyl）carbodiimide,EDC]进行化学交联。分别采用体积法和体外酶解实验测定支架材料孔隙率和降解率,扫描电镜观察交联前后支架材料的形态变化。取3周龄新西兰兔髁状突软骨细胞,体外培养5d后,甲苯胺蓝染色,倒置相差显微镜下观察行细胞鉴定。取消化后第2代软骨细胞接种至支架材料复合培养,倒置相差显微镜下观察细胞生长情况。复合培养1、3、5、7和10d后,PBS液清洗3次,置入24孔板并以0.25%胰酶和0.1%EDTA消化细胞,采集细胞进行细胞计数并绘制细胞生长曲线。另取部分样本继续培养5d,行组织学和扫描电镜观察。结果胶原-透明质酸支架材料经化学交联后,具有合适的三维多孔结构,孔隙率为83.7%,孔径100-120μm;交联后抗酶解能力显著增加。髁状突软骨细胞在其表面和内部贴附良好,形成细胞-材料复合体,细胞增殖实验显示,复合培养1d,材料中细胞数为3.7×104/支架,10d后增至8.2×104/支架。电镜观察见细胞周围有基质分泌。结论EDC交联后的胶原-透明质酸支架具有良好空间结构和生物相容性,可作为支架材料用于髁状突软骨组织工程的研究。     

GS10AN ACUTE CARE SURGICAL SERVICE – A CHANGE IN PARADIGM

Background The provision of acute surgical care in the public sector is becoming increasingly more difficult due to the limitation of resources. The lack of predictability of access to theatres during the working day has the effect of displacing elective cases or forcing some acute cases to be performed after hours. An Acute Care Surgical Service was constructed at the Prince of Wales Hospital so as to provide acute surgery in a more timely and efficient manner. Methods A roster of 8 general surgeons was constructed to provide onsite service during the working day and on call service after hours for a 52 week period. An acute care ward of 4 beds and an operating theatre was placed under the control of the Acute Care Surgeon (ACS). At the end of the ACS roster all patients whose treatment was incomplete were handed on to the next rostered ACS. Patient data and theatre utilisation data was prospectively collected and compared to the preceding 52 week period. Data was analysed using unpaired t‐test. Results Emergency theatre utilization during the day increased from 55% to 70%. There was a 15% reduction in acute care operating after hours. Fewer cases were done between midnight and 0800. There was more efficient use of the entire theatre block suggesting a significant cultural change. Staff satisfaction was high. Conclusion On site consultant driven surgical leadership has provided significant positive change to the provision of Acute Surgical Care in our institution. The paradigm shift in acute surgical care has improved patient and theatre management and stimulated a cultural change of efficiency.     

ES13PHEOCHROMOCYTOMA – AN ANALYSIS OF 123 PATIENTS

Background Pheochromocytomas are diagnosed in <1% of patient evaluated for hypertension. Methodology A retrospective analysis of case records of those patients with histopathologically confirmed pheochromocytoma in our hospital from 1976–2006 [30 YEARS] was conducted. Result A total of 123 patients were diagnosed during this period. The median age at presentation was 31 years (range 9–71) with a male to female sex distribution of 75% and 36%. 80% were hypertensive at the time of diagnosis. Headache(84%), palpitations(64%) and sweating(60%) are the most common presenting complaints.Tachycardia [>100 per minute]were seen in 31%. Hypertensive changes in eyes were seen in 87%. In ECG, QTc prolongation in 26%, left ventricular hypertrophy in 30%. Diabetes mellitus/IGT was seen in 35%. Elevated urinary VMA (24 hrs) was seen in 93% when done on 3 consecutive days. MIBG was positive in 85%. Malignant pheochromocytoma was diagnosed by tumour invasion/metastasis seen 10.44%. Extra adrenal pheochromocytoma 18%, followed by bilateral pheochromocytoma in 11%. Hereditary pheochromocytoma in 13% which include 5 with Von Hippel Lindau and 6 with MEN. A median follow‐up was 12 months (range 1–204) in which persistent hypertension was seen in 16%. Cholelithiasis in 7%. Conclusion In our case series the mean age (31 yrs) of presentation seems to be younger compared to other case series. 16% of our patients were asymptomatic at the time of presentation. Urinary VMA was elevated in 93% of patients when done in 3 consecutive samples. Extra adrenal pheo was common in our patients (18%). MIBG was false negative in 15% of those patients with pheochromocytoma.     

VALUE OF THE PROSPECTIVE ‘BEFORE AND AFTER’ STUDY AS A METHODOLOGY TO EVALUATE OUTCOME IN A TRAUMA CENTRE

A series of interventions (administrative, clinical and educational) was introduced to improve the quality of trauma care at Royal Prince Alfred Hospital, the designated trauma centre for the Central Sydney Area Health Service (CSAHS). A prospective, ‘before and after’ study was conducted to assess changes in outcome following the introduction of these measures. The trauma centre survival rate for patients admitted with serious injury (Injury Severity Scores > 15) increased significantly, from 72% in the nine months before trauma centre designation to 89% in the nine months after (P= 0.005). The peer review designated, potentially avoidable death rate did not change significantly over the two study periods, remaining in the 20–30% range. Similarly the unexpected death rate (TRISS) did not change significantly, remaining in the 20–45% range. A trend to a lower trauma centre mortality in those arriving with a systolic blood pressure 90 mmHg was noted. Seven out of 14 patients ‘at risk’ from exsanguination died in the first 9 months compared with one out of seven in the second 9 months (P = 0.17). An unexpected finding was a change in the degree of injury severity and physiological status in patients arriving at the trauma centre. The Injury Severity Scores were significantly lower (P= 0.008) and the Revised Trauma Scores significantly higher (P= 0.0006) in the latter 9 months of the study. It was concluded that the improved trauma centre survival rate was a reflection of a reduced hospital mortality from haemorrhagic shock in conjunction with a lesser degree of injury severity in patients admitted from the CSAHS.     

PR01“A PICTURE SPEAKS A THOUSAND WORDS”– THE USE OF DIGITAL PHOTOGRAPHY AND THE INTERNET IN MONITORING FREE TISSUE TRANSFER

Purpose Post operative monitoring is crucial for the success of microsurgical free tissue transfer. Sophisticated and expensive methods are available for monitoring. We propose a novel technique using digital photography and the internet as a reliable and cost effective method to monitor free tissue transfers. Methods 163 micro‐vascular procedures were monitored using this technique over 8 months. Serial photographs taken to show flap color. Capillary refill time, pin prick‐ bleed time and color and hand held Doppler signal was recorded in the movie mode of a standard 5 mega pixel camera with duration of 15 seconds. Data was sent to the surgeon at regular intervals and or as deemed necessary. Results Analysis of the 67 cases is presented. 5 re‐explorations were done. The early diagnosis of venous congestion was possible using this technique. Timely intervention contributed to the success of the re‐explorations and these flaps could be salvaged. The file size of images was in the range of 1 MB–6 MB. The file size of an entire set of images ranged about 7 MB–9 MB. These were sent across the ADSL internet lines. Conclusion The use of the digital images and the internet allow reconstructive surgeons to have a reliable picture of the state of their free tissue transfers. This permits decrease in observer error and saves valuable time which otherwise needs to be spent to verify situations of doubt and offers an ideal solution to the logistic problem of having to visit the patient in case of doubt.     

TS15PUNCOMMON ABDOMINAL HEMORRHAGE DUE TO BLUNT TRAUMA: BLENDING FROM AN ASYMPTOMATIC ABDOMINAL TUMOR INJURY – A CASE REPORT

Asymptomatic tumors are not uncommon, may be diagnosed during clinical examination or during surgical interventions for other purposes such as treatment of a hemorrhage due a blunt trauma. Case report 6 year‐old boy had fallen, hitting his abdomen against a rock, and arrived at hospital ten hours later. Initial assessment he was complaining of diffuse abdominal pain; his physical examination showed: respiratory rate: 16 mov/min, blood pressure: 100 × 80 mmHg, heart rate: 100 bat/min, and Glasgow coma score: 15. His abdomen was distended, with guarding and rebound tenderness, and had a palpable mass. FAST ultrasound was positive; and Ct‐scan showed an abdominal mass with 15 × 12 × 7 cm dimension, and moderate amount of free blood in the abdominal cavity. Laboratory tests showed: hemoglobin 9.9 mg/dl, hematocritic 28.8%, white blood cells 6.900 cel/dl. Midline laparotomy was performed, a large, injured and bleeding mesenteric mass was found encircling superior mesentery artery and several small bowel loops; 500 ml of free blood was found in the peritoneal cavity. Mesenteric mass was partially removed with a segment of the small bowel. Findings of anatomico‐pathologic examination revealed an intestinal Burkitt lymphoma, with mesenteric linfonodes. Patient had an uneventful postoperative course, and started with quimotherapy. Comments This case report shows an unusual traumatic abdominal blending that could not be clearly diagnosed before laparotomy was performed. The emergency of this case was bleeding control, decision to remove mass was taken only for this purpose, and not to treat the tumor. As removal of the whole mass was impossible, a partial removal was performed.     

FRESH OSTEOCHONDRAL ALLOGRAFTS: A 6–10-YEAR REVIEW

Background : In young patients with limited articular cartilage damage, osteochondral allografts may offer an alternative to total joint replacement. The survival of chondrocytes after transplantation and the correlation with clinical outcomes was studied. Methods : Between March 1987 and September 1990, nine patients received fresh osteochondral allografts. Three patients received tibial plateau transplants, three received patellar transplants, two received proximal interphalangeal joints and the remaining patient received segmental femoral head allograft. Patient ages ranged from 16–51 years (mean = 30). They have been followed in prospective manner for up to 10 years with clinical, radiographic and histopathological review during that period. Results : Early histological analyses demonstrated preservation of hyaline cartilage. Subsequent analyses from the periphery of some grafts demonstrated chondrocyte death and change from hyaline cartilage to fibrocartilage, but one specimen taken from the centre of tibial plateau graft, nine years after transplantation, demonstrated viable chondrocytes. The three tibial plateau recipients improved at clinical level from an average pre-operative score of 73 (HSS 0–200) to postoperative average of 174 points. Two of those patients receiving patellar allografts improved from 91 points to 181 points on average. The third patella allograft recipient underwent total knee replacement 18 months post-transplantation. The patella was not resurfaced. The proximal interphalangeal joint transplants failed and the femoral head allograft has been lost to follow-up. Conclusions : The clinical success of the tibial plateau and patellar allografts, irrespective of the histological results, has resulted in the formulation of code of specific indications for this operation. Future enthusiasm, although buoyed by the possibility of long-term chondrocyte viability and good clinical results, must be tempered by the ever-present risk of disease transmission.     

EFFECTS OF PRESSURE GARMENT ON PATIENTS UNDERGOING MODIFIED RADICAL MASTECTOMY — A PROSPECTIVE RANDOMIZED TRIAL

Introduction: The treatment of choice for breast cancer is modified radical mastectomy or in selected case breast conserving surgery. Typically, patient will have a long hospital stay after surgery due to the collection of lymph. Premature removal of drain will incur seroma formation and may predispose to wound infection. Review of literature shows that there has not been adequate address to this condition, particularly the use of pressure garment in reducing lymph output. We report our experience in an interim analysis of a randomized controlled study. The aim of the study is to evaluate the effects of pressure garment on early removal of drains, shortening of hospital stay and reducing the incidence of seroma formation. Methodology: From September 1999 to November 2000, 44 consecutive patients undergoing modified radical mastectomy for breast cancer were invited to participate in this study. Our occupational therapist arranged for tailor made pressure garments. Soft foam mimicking the external mammary prosthesis was fashioned so that appropriate pressure was applied on to the operative site to prevent lymph accumulation. They were randomized into two groups (1) with pressure garment (2) without pressure garment. The single surgeon performing the mastectomy was blinded until the completion of surgery when the result of randomization was sought from the principal investigator. The occupational therapist inspected daily to ensure the vest was filled satisfactorily. OPD assessments were arranged at 2 weeks and 8 weeks. Results: (range in parentheses) Conclusion: Use of breast pressure garment did not prevent seroma formation but reduced the volume of drainage and facilitated early removal of drains resulting in a significant reduction in the length of hospital stay of 2.7 days. Such breast vest has great impact on the hospital economy.     

SO14PPERIOPERATIVE OUTCOMES OF CYTOREDUCTIVE SURGERY AND PERIOPERATIVE INTRAPERITONEAL CHEMOTHERAPY FOR NON‐APPENDICEAL PERITONEAL CARCINOMATOSIS FROM A PROSPECTIVE DATABASE

Purpose Cytoreductive surgery and perioperative intraperitoneal chemotherapy has expanded its application in the management of peritoneal carcinomatosis from gastrointestinal and ovarian malignancies. An accurate assessment of perioperative outcomes is crucial for integration of this combined procedure into clinical practice. Methodology A prospective study of 80 patients undergoing the combined treatment for non‐appendiceal peritoneal carcinomatosis was conducted. Forty‐seven adverse events by 8 organ‐systems were rated from Grade I to IV with increasing severity. Grade I morbidity was self‐limiting; Grade II required medical treatments; Grade III required an invasive intervention; and Grade IV required returning to the operating room or intensive care management. Results One patient (1.3%) died postoperatively. Postoperative adverse events affected genitourinary system (38%), haematological system (31%), gastrointestinal system (25%), infection (20%), intravenous catheters status (15%), pulmonary system (14%), cardiovascular system (11%), and neurological system (4%). Thirty‐six patients (45%) experienced 49 Grade III adverse events. Six patients (8%) experienced 8 Grade IV adverse events. More than 4 peritonectomy procedures (p = 0.010), and length of hospital stay of more than 21 days (p = 0.007) were strongly associated with Grade III and/or Grade IV morbidity. Conclusions The morbidity and mortality rates after the combined treatment for non‐appendiceal peritoneal carcinomatosis were within the acceptable range of surgical treatments for other gastrointestinal cancers. A standardized prospective database is required for an accurate assessment of perioperative outcomes.     

BUERGER'S DISEASE – A REVIEW OF 105 PATIENTS

One hundred and five cases (101 males and four females) of Buerger's disease occurring In Hong Kong have been reviewed. In the foot the digits affected were predominantly the big, second and little toes, whereas in the hand the index and middle fingers were most commonly involved. There was no selective involvement of the left or right side In the upper or lower extremities. The majority of patients were operated on and had amputation, sympathectomy, or both procedures performed. Major lower limb amputation was carried out in 22.6% of patients with lower limb involvement. Reconstructive arterial surgery was possible In only four patients, and early failure of grafts In three patients resulted in major amputation.     

AL01PACIFIC ISLANDS PROJECT – PAST PRESENT AND FUTURE

The Pacific Islands Project began in 1995 and in its early years had a focus on providing specialist services that were not available in the 10 island nations visited. In 2002 Nauru was added and PIP Phase III will end its 9 month bridging/extension phase in September 2007. During the last 12 years Fiji School of Medicine has commenced a postgraduate medical training program in surgery similar to that has been in existence in PNG since 1975. There are now a growing number of Pacific‐trained surgeons who can select suitable cases, do some of the surgery, and supervise the postoperative care. Increasingly visiting teams have focused on transferring skills and building local capabilities (capacity building). The RACS, the Project Director and the speciality coordinators have managed the first three phases of the project in Australia. Phase III had on‐going evaluation by an internal RACS committee under the chairmanship of Professor Hamish Ewing. AusAid also externally reviewed the project late in 2006. That review was generally complimentary as to what has been achieved but also points to some new goals for the future. At the time of writing this abstract the future direction of PIP is yet to be decided and designed. This will be done mid 2007. However, it is to be hoped there will be a new program, focused on capacity building, that is managed in the Pacific and employs the skills of Pacific Island Specialists wherever possible. RACS is likely to continue to play an important role in sourcing visiting specialists, organising training positions, arranging courses. We have much expertise to offer but there is no longer any need for us to set the agendas.     

DEVELOPMENT OF SMALL DIAMETER INTRAMEDULLARY NAILS MADE FROM ISO 5832–9 STAINLESS STEEL

Background : In order to improve strength in small diameter intramedullary nails, a system was designed in which the implants were manufactured from 30% coldworked ISO 5832–9 stainless steel. Methods : Nail diameters were 9 and 10 mm for the femur, and 8 and 9 mm for the tibia. The nails were solid rods and the screws were partially threaded. Pre‐clinical bending yield tests established that the 8‐, 9‐ and 10‐mm diameter rods had strengths comparable, respectively, with 10‐, 12‐ and 14‐mm diameter Grosse–Kempf nails. Forty‐eight femoral and 98 tibial shaft acute fractures were treated with this system. Postoperatively, patients were allowed to gently bear weight as tolerated. Results : There was one broken nail, occurring 10 months after femoral nailing. There were six broken screws, occurring between 3 and 6 months postoperatively in two patients and after more than 6 months in four patients. The broken screws had no adverse clinical effect. Five patients required late bone grafting or exchange nailing, and 15 patients required dynamization. Conclusion : This design of small diameter locked intramedullary nails was strong enough to allow early weightbearing.     

THE MANAGEMENT OF INJURIES –A REVIEW OF DEATHS IN HOSPITAL

A prospective review was undertaken of the management of III consecutive patients who died in hospital after admission for treatment of injuries. A standard set of data relating to each patient was reviewed by each member of a trauma death audit committee and then by the whole committee. Autopsy reports were available on all patients. Conclusions were drawn concerning defective aspects of patient management and possible avoidance of each death. Injury severity was assessed using the Trauma Score (TS) and Injury Severity Score (ISS). The possibly avoidable death (PAD) rate was 17%. The most common defects in management were related to inadequate fluid resuscitation and delays in definitive management. The greatest contributions to the PAD rate were from inadequate fluid resuscitation. delays and inadequate perception of the severity of injuries or significance of clinical deterioration. Increasing age was related to a higher frequency of PAD. PAD rate in the presence of severe head injury was 8%, hut was 63% in the absence of a severe head injury. It is concluded that review of all trauma deaths is an achievable. beneficial and essential part of a hospital-based integrated trauma service. TS and ISS are not sufficiently sensitive to justify their use in selecting deaths for review. Improved blood volume replacement, earlier and more direct management and supervision by senior specialist staff. and elimination of causes of delay in patient management should all decrease the death rate from injuries particularly in patients without severe head injury.