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Biomedical subjects

M Mars

Publications and source records attributed to M Mars.

At least 37 records · Page 2Linked to original sources
PubMed1999

An audit of clinical teaching in paediatric surgery to interns and surgical registrars.

OBJECTIVES: The study aimed to assess the knowledge increment in paediatric surgery of interns (pre-registration) after a 1-month period of training and of registrars after a 6-month rotation. A comparison of the knowledge base of interns from different universities was included. DESIGN: A standard questionnaire was completed by all interns and registrars on the first day of their appointment and again at the end of rotation. Knowledge increment was assessed for each student and each question. SETTING: King Edward VIII Hospital, Durban, South Africa. SUBJECTS: Interns (equivalent to pre-registration house officers) and registrars (registered practitioners) undergoing general surgical training. RESULTS: Both registrars and interns improved their test scores after their training period. However, satisfactory exit scores were achieved by interns in only 72% of questions. CONCLUSIONS: This study forms the basis for assessing future educational strategies and has identified areas of teaching weakness which can be remedied. The reduction in exposure of interns to clinical paediatric surgery must be balanced by more efficient use of teaching time.

Education, Medical, Graduate↗
PubMed1999

Aorto-iliac occlusive disease in the different population groups--clinical pattern, risk profile and results of reconstruction.

BACKGROUND: It has previously been accepted that atherosclerotic disease is uncommon among blacks worldwide; however, recent studies have increasingly reported atherosclerotic disease in this group. STUDY DESIGN: Prospective study of hospital patients with aorto-iliac occlusive disease presenting to the vascular service of the Durban metropolitan hospitals. The study was designed to assess clinical pattern, risk profile and results of reconstruction in these patients. METHODS: This is a study of 688 patients with aorto-iliac occlusive disease managed over 9 years in Durban, with clinical pattern and risk factors compared in the different population groups. A subgroup of 492 patients underwent aortobifemoral bypass, providing material for comparison of the results of reconstruction in the different population groups. RESULTS: More black patients presented with gangrene and threatened limb, whereas whites tended to present early with claudication. All groups had hypertension and diabetes as risk factors. In addition, whites and Indians had ischaemic heart disease, which was not found among blacks. Mortality was 5% (blacks 1.8%, whites 8.5%, Indians 5%). Medium-term occlusion rates were 19% in blacks, 13% in Indians and 5% among whites. Five-year cumulative patency rates were 92% for whites, 77% for Indians and 74% for blacks. CONCLUSION: Whites do significantly better than blacks, who tend to present at an advanced stage of the disease. The presence of ischaemic heart disease among whites and Indians contributes to the higher mortality in these groups.

Adult↗
PubMed1998

High intensity exercise: a cause of lymphocyte apoptosis?

Post exercise lymphocytopenia is well documented and attributed to egress of lymphocytes from the vascular compartment. Recent studies have reported exercise induced DNA damage in leukocytes and have questioned a possible link to apoptosis. Eleven subjects underwent a ramped treadmill test to exhaustion. Venous blood samples were taken before, immediately post exercise, and 24 and 48 hours after exercise. Single cell gel electrophoresis revealed evidence of single strand DNA damage in 10% of lymphocytes immediately after exercise, but not at other times. Fluorescent microscopy showed three patterns of DNA distribution, similar to those seen in apoptosis, at all times after exercise. Three subjects underwent the same exercise protocol, and lymphocytes were prepared for flow cytometry to determine apoptosis using the TUNEL method. Flow cytometry revealed lymphocyte apoptosis in 63% of lymphocytes immediately after exercise and 86.2%, 24 hours after exercise. Lymphocyte apoptosis is documented for the first time after exercise and may in part account for exercise induced lymphocytopenia and reduced immunity.

Apoptosis↗
PubMed1998

Raised compartmental pressure in children: a basis for management.

In children, raised intracompartmental pressure which may lead to a compartment syndrome is relatively common and follows a wide variety of insults. Cell viability is compromised at much lower compartmental pressures than in adults, and clinical awareness must be heightened, especially in the hypotensive child. Suspicion follows an awareness of clinical situations associated with the risk of raised compartmental pressure. Clinical confirmation may be difficult in the context of the uncooperative child. Diagnosis is established by invasive pressure monitoring. Intervention becomes mandatory when the compartmental pressure has risen to within 30 mmHg of the mean arterial pressure, which varies with the age and clinical status of the child. Management is by fasciotomy which should be wide and open and decompress all affected compartments. Thirty children with raised intracompartmental pressure are reported: 21 children were managed non-operatively and nine underwent fasciotomy. Two children with absolute intracompartmental pressures of 28 mmHg and 35 mmHg required fasciotomy, whereas five children with intra-compartmental pressures between 30 mmHg and 44 mmHg were managed non-operatively. In this latter group this policy resulted in no demonstrable morbidity.

Child↗
PubMed1998

Raised intracompartmental pressure and compartment syndromes.

Raised intracompartmental pressure (ICP) has become recognized as the final common pathway of a variety of pathologies which lead to failure of the microcirculation with resultant tissue hypoxia and cell death. While commonly seen after trauma, either accidental or operative, raised ICP may result from either an increase in the volume of tissue within a closed osseo-fascial or fascial compartment or by the application of an external force compressing a compartment, and it is associated with a wide variety of insults. The advent of reproducible techniques of measuring ICP has added science to a well-recognized clinical picture and allowed a rational approach to management. Controversies still remain, particularly in regard to the level of pressure at which intervention becomes mandatory, and the role of prophylactic interventions. This review attempts to present current thinking on the pathophysiology of the microcirculation and the background to these controversies.

Adult↗
PubMed1998

A comparison of laser Doppler fluxmetry and transcutaneous oxygen pressure measurement in the dysvascular patient requiring amputation.

OBJECTIVE: To determine the predictive power of laser Doppler fluxmetry (LDF), both heated and unheated, as a preoperative investigation of wound healing potential in dysvascular patients requiring amputation, by comparison with transcutaneous oxygen pressure measurement (TcpO2) and the limb to chest TcpO2 index. METHODS: Thirty-five non-diabetic patients with peripheral vascular disease were investigated before amputation. Heated and unheated LDF and heated TcpO2 measurements were taken on the chest wall and at the routine above-knee, below-knee and mid-foot amputation levels. Wound healing potential was evaluated against a TcpO2 index value of 0.55 and on clinical outcome. RESULTS: A heated LDF value of 4.9 arbitrary units (au) was shown by receiver-operator characteristic curve to have the best predictive power, with an overall accuracy for preoperative prediction of wound healing of 91.4%, and a predictive value for wound failure of 89%. Based on the heated LDF of 4.9 au, review of 26 amputations performed shows the overall accuracy for preoperative prediction of wound healing of 92.3%, a predictive value for wound healing of 100%, and a predictive value for wound failure of 62.5%. CONCLUSION: A heated LDF value of 4.9 au appears to be a useful predictor of the potential of an amputation site to heal.

Amputation, Surgical↗
PubMed1998

The response of the dietary anti-oxidants vitamin E and vitamin C to oxidative stress in pre-eclampsia.

The relationship of oxidants and anti-oxidants in preeclampsia with reference to the dietary anti-oxidants vitamin C and vitamin E was investigated. Three groups of patients were studied in the third trimester of pregnancy: normotensives ( n = 32), mild pre-eclamptics ( n = 15) and severe pre-eclamptics ( n = 31) with a group of healthy non-pregnant women ( n = 18) serving as a control. Total anti-oxidant concentration, the concentrations of vitamin C, vitamin E, superoxide dismutase, uric acid and the concentration of total oxidant activity, as reflected by lipid peroxides, were measured in plasma or red blood cells. Total anti-oxidants and vitamin C concentrations were significantly lower in pre-eclamptic patients than in pregnant controls (P < 0.05), with the concentrations in the pregnant controls being significantly lower than in the non-pregnant controls (P < 0.05). There was no significant difference in vitamin E concentration for all four groups. Superoxide dismutase activity was significantly lower in the normal pregnancy group. Lipid peroxides were significantly increased in the three pregnant groups (P < 0.05) with no differences noted between these groups. The relationship of oxidants to anti-oxidants in pregnancy and pre-eclampsia is dependent on many factors but balance appears to be upset in pre-eclampsia. The reduction in anti-oxidant concentrations in pre-eclampsia suggests either a primary deficit or consumption of the anti-oxidants measured. Of the dietary anti-oxidants studied, vitamin C was most affected in pre-eclampsia.

Journal Article↗
PubMed1998

Alveolar bone grafting: a review of 115 patients.

The results of alveolar bone grafting carried out at The Hospital for Sick Children, Great Ormond Street, London, UK, between January 1982 and January 1989 were assessed. Cancellous bone from the iliac crest was grafted to alveolar cleft defects in 115 patients (63 male and 52 female). Eighty-seven unilateral (58 left and 29 right) and 28 bilateral clefts were operated on. The mean age at the time of operation was 11.5 years, with a range of 8.08-18.75 years. The cleft canine had erupted prior to bone grafting in 58.4 per cent. At the time of this study the cleft had erupted in 96.35 per cent and was unerupted in 3.65 per cent of sites. Radiographs were taken at regular intervals and assessed according to previously reported criteria. Eighty-six per cent were clinically successful (Type I and II). In Type III 10.95 per cent had less than three-quarters of the normal interdental septal height and 2.18 per cent failed (Type IV). In addition, 3.6 per cent of sites showed cervical root resorption affecting the adjacent incisor and 1.4 per cent internal resorption of the cleft canine.

Adolescent↗
PubMed1998

Bilateral alveolar bone grafting: a report of 55 consecutively-treated patients.

A retrospective study was undertaken to evaluate the long-term results of bilateral alveolar bone grafting carried out at Great Ormond Street Hospital from 1983 to 1993. Fifty-five consecutive complete bilateral cleft lip and palate patients (36 males and 19 females) who had the operation were included in this study. The total number of cleft sites was 110. At the time of alveolar bone grafting, the mean age of the patients was 12.3 years with a range of 8.4-19.9 years. Cancellous bone from the iliac crest was grafted into the alveolar cleft areas. The cleft sites were studied in two groups according to whether the cleft canine had erupted prior to bone grafting or not. The erupted canine group was composed of 43 cleft sites and the unerupted canine group of 67 sites. At the time of this study, the cleft canine had subsequently erupted at 101 sites. Anterior occlusal radiographs were taken before and after bone grafting. The minimum period of observation after alveolar bone grafting was one year. Criteria described previously were utilized to assess the height of the interdental septum. The results show that bone grafting before canine eruption has a higher clinical success rate compared with that carried out after canine eruption. The critical variable affecting the quality of bilateral alveolar bone grafting is the timing of the surgery.

Adolescent↗
PubMed1998

Gunshot injuries in infants and children in KwaZulu-Natal--an emerging epidemic?

OBJECTIVES: To determine the pattern of firearm injuries in children under the age of 13 years admitted to a paediatric surgical unit in KwaZulu-Natal and to assess the impact of such injuries on hospital resources. DESIGN: Retrospective review of the Department of Paediatric Surgery and hospital databases for all gunshot admissions, 1983-1995 inclusive. SETTING: King Edward VIII Hospital, Durban. SUBJECTS: Children aged 12 years and under admitted to the care of the Department of Paediatric Surgery for management of gunshot injuries. METHODS: Data retrieved included demographic details, circumstances of injury, duration of hospital stay, management and outcome in terms of mortality and long-term morbidity. RESULTS: One hundred and six patients were identified, of whom 96 were available for review. There has been a rapid escalation of numbers presenting. During 1994-1995, an additional 38 children with gunshot injuries were admitted to other units within Durban academic hospitals. The mean age of injury in patients admitted to the Department of Paediatric Surgery was 6.4 years and the abdomen was the most frequently injured area. Multiple injuries were common. The in-hospital mortality rate was 10.4%. Major morbidity, including paraplegia, hemiplegia, amputation and major peripheral nerve deficit, was seen in 11.4%. Duration of bed occupancy in the general surgical ward reached 247 days in 1995. CONCLUSION: There is an increasing incidence of gunshot injuries in this region. Of children surviving to reach hospital, 10% die and 11% are left with lifelong major morbidity. Most victims are innocent bystanders and too young to be considered active participants. Prevention will require sociopolitical stability and the disarming of the community.

Age Factors↗
PubMed1998

Aortobifemoral bypass in the presence of superficial femoral artery occlusion: does the profunda femoris artery provide adequate runoff?

Of a total of 492 patients (984 limbs) undergoing aortobifemoral bypass for aorto-iliac disease, 123 limbs with occlusion of the superficial femoral artery (SFA) were compared with 861 limbs with a patent SFA, and were prospectively monitored to assess the efficacy of the profunda femoris artery (PFA) as sole 'runoff' of this operation. There were more late occlusions in the limbs with occluded SFA (15%) compared to those with a patent SFA to begin with (7%). The five-year patency rate was 87% for limbs with patent SFA and 80% for limbs with occluded SFA. Claudicants had a higher 5-year patency rate compared to threatened limbs irrespective of runoff. We conclude that profunda femoris can be used as sole runoff although the rate of occlusion tends to be higher in this group compared with counterparts with patent SFA.

Adult↗
PubMed1997

Towards reducing the trauma of direct intracompartmental pressure measurement for children: an in vitro assessment of small-diameter needles

Direct intracompartmental pressure (ICP) measurement in children is an important investigation, the use of which may be inhibited by the invasive nature of the procedure and the large 18-gauge (G) needles that have hitherto been recommended. These large needles contribute to patient, parental, and physician anxiety. This study compares ICP measurements using needles of different lengths and port configuration, ranging from 18 to 25 G, against the "gold standard" 18 G, long, double-ported needle. All except the 18 G long, single-ported needle had limits of agreement within 3 mm Hg of the gold-standard needle. The results indicate that needle manometry can confidently be performed using small needles, and that the addition of a side-port is unnecessary in needles of small volume.

Journal Article↗
PubMed1997

Study models of 5 year old children as predictors of surgical outcome in unilateral cleft lip and palate.

This study examined features of dental occlusion in patients born with a unilateral cleft lip and palate (UCLP). The intention was to develop a 'Goslon type' index for 5 year old children. The Goslon ranking system was used on longitudinal study models taken at 5 and 10 years of age of the same patients. All patients had UCLP and this had been repaired using a Millard type lip repair and a Veau Wardill or Von Langenbeck palatal closure. There was good intra-examiner agreement for ascribing 5 and 10 year old models to one of five categories (excellent-very poor). Inter-examiner agreement on both sets of models was at worst moderate. Two of the examiners identified up to 93 per cent of 5 year old models which either remained in the same category or deteriorated by 10 years of age. At worse the results demonstrated 70 per cent of cases of 5 years of age remained in the same category or deteriorated by 10 years of age. Consensus agreement has produced five categories of outcome for these 5 year old models. This new index is to be subjected to further validation. This study has therefore provided, for the first time, a mechanism for assessing the results of CLP surgery earlier than indices already available.

Child↗
PubMed1997

Three-dimensional analysis techniques--Part 4: Three-dimensional analysis of bone and soft tissue to bone ratio of movements in 24 cleft palate patients following Le Fort I osteotomy: a preliminary report.

The three-dimensional changes in the bone and the ratio of soft tissue to bone movement were investigated in a group of 24 cleft palate patients following Le Fort I osteotomy. CT scans were taken for each patient preoperatively and 1 year postoperatively. The scans were superimposed, radial measurements calculated, and the changes illustrated by two separate color scales. In all of the groups, there was a fairly consistent pattern of movement over the mandible. The soft tissues moved in a 1.25:1 ratio over the chin and canine regions, and reduced to 1:1 over the body. In the maxilla, there was a 1:1 movement in the midline increasing to 1.25:1 bilaterally over the alar bases for both the bilateral clefts and clefts of the secondary palate groups. In the unilateral cleft group, however, there was a greater degree of movement over the cleft than over the noncleft side.

Adolescent↗
PubMed1997

Towards reducing the trauma of direct intracompartmental pressure measurement for children: an in vitro assessment of small-diameter needles.

Direct intracompartmental pressure (ICP) measurement in children is an important investigation, the use of which may be inhibited by the invasive nature of the procedure and the large 18-gauge (G) needles that have hitherto been recommended. These large needles contribute to patient, parental, and physician anxiety. This study compares ICP measurements using needles of different lengths and port configuration, ranging from 18 to 25 G, against the "gold standard" 18 G, long, double-ported needle. All except the 18 G long, single-ported needle had limits of agreement within 3 mm Hg of the gold-standard needle. The results indicate that needle manometry can confidently be performed using small needles, and that the addition of a side-port is unnecessary in needles of small volume.

Child↗
PubMed1997

Choosing the proximal anastomosis in aortobifemoral bypass.

BACKGROUND: The preferred method of proximal aortic anastomosis (end to end or end to side) in aortobifemoral bypass remains controversial. METHODS: This is a study of 492 patients who had an aortobifemoral bypass for aortoiliac disease over 9 years in which end-to-end (166 patients) and end-to-side (326 patients) proximal aortic anastomoses were compared. The decision as to the type of anastomosis was made at operation, depending on the severity of aortic disease. Outcome was related to the site of the proximal anastomosis and the state of the distal run-off. RESULTS: The overall perioperative mortality rate was 5 per cent. Early graft occlusion occurred in six patients in the end-to-side group and none in the end-to-end group. During follow-up nine patients (5 per cent) had graft occlusion following end-to-end anastomosis and 56 (17 per cent) following end-to-side anastomosis (cumulative patency 87 and 75 per cent respectively). Patency was not affected by the distal run-off. DISCUSSION: End-to-end anastomosis yields significantly better results than end-to-side anastomosis irrespective of distal run-off.

Adult↗