Radiation exposure to comforters and carers during paediatric molecular radiotherapy.

BACKGROUND: To show whether the incidental radiation exposure received by comforters and carers of children undergoing molecular radiotherapy was kept as low as reasonably achievable and was within English national dose constraints. PROCEDURE: The radiation exposure of adult comforters and carers was routinely monitored with a whole body personal dose meter while the child was in hospital. Data were collected on iodine-131 meta-iodobenzylguanidine (131 I-mIBG), lutetium-177 DOTATATE (177 Lu-DOTATATE), and iodine-131 sodium iodide (131 I-NaI) treatments. RESULTS: Data were available for 50 treatments with high-administered activity double-infusion 131 I-mIBG and 12 single administrations; 15 177 Lu-DOTATATE treatments and 28 131 I-NaI administrations. The median age was 7 years (1-18). The median administered activity of: 131 I-mIBG was 16.2 GBq (6.8-59 GBq) for double infusion patients and 8.1 GBq (5.26-16.25 GBq) for single administrations; 177 Lu-DOTATATE was 7.2 GBq (2.5-7.5 GBq); and 131 I-NaI was 3 GBq for thyroid remnant ablation and 5.5 GBq for cancer therapy. The median number of comforters and carers for all administrations was 2 (range 1-9). The median exposure values for comforters and carers for high-administered activity 131 I-mIBG administrations was 302 µSv (0-5282 µSv); for single fraction 131 I-mIBG 163 µSv (3-3104 µSv); 177 Lu-DOTATATE 6 µSv (1-79 µSv); and 131 I-NaI 37 µSv (0-274 µSv). Only one of the comforters and carers exceeded the dose constraint of 5 mSv. CONCLUSIONS: Doses to comforters and carers were in all but one case within the dose constraint nationally recommended by the Health Protection Agency, now part of Public Health England. New evidence is presented which show that comforter and carer radiation exposure levels from paediatric molecular radiotherapy in routine clinical practice are acceptably low. Pediatr Blood Cancer 2015;62:235-239. © 2014 Wiley Periodicals, Inc.

Maternal endocrine adaptation throughout pregnancy to nutrient manipulation: consequences for sexually dimorphic programming of thyroid hormones and development of their progeny.

Maternal nutrient restriction during critical windows of fetal development alters postnatal growth, often in a sexually dimorphic manner. Intrauterine growth restriction is frequently characterized by accelerated growth and increased adiposity in later life. Thyroid hormones are implicated as part of the mechanism involved in this scenario via their actions within the hypothalamic-pituitary-thyroid axis. We fed high (H = 240%) and low (L = 70%) levels of recommended daily crude protein intake during the first and second trimesters of gestation to beef heifers to investigate effects to their progeny's plasma concentrations of free and total triiodothyronine (FT3 and TT3) and thyroxine (FT4 and TT4) from birth until weaning at 191 days of age (n = 68). The study design was a two-by-two factorial. For male progeny, exposure to maternal diets low in protein during the first trimester of gestation resulted in greater FT4 at birth (P < 0.05) which was subsequent to lower concentrations of leptin in maternal plasma at 271 days of gestation compared with their high-protein-exposed counterparts. These same animals went on to have greater milk intake during the latter half of the lactation period (P < 0.05) and exhibited faster rates of average daily gain (ADG) relative to birth weight during this time (P < 0.05). For all progeny, independent of sex, exposure to low-protein maternal diets during the second trimester of gestation resulted in greater FT3 relative to TT3 at birth. Because FT3 at birth and 29 days was positively associated with ADG (P < 0.05) and ADG relative to birth weight (P < 0.05), it is proposed that FT3 plays an integral role in catch-up growth in the bovine as per other species. Protein intake during the first and second trimesters of gestation has a sexually dimorphic effect on progeny plasma thyroid hormone concentrations, and these changes are associated with altered milk intake and postnatal growth pathway.

Arterial stiffness, central blood pressure and body size in health and disease.

BACKGROUND: Body size is associated with increased brachial systolic blood pressure (SBP) and aortic stiffness. The aims of this study were to determine the relationships between central SBP and body size (determined by body mass index (BMI), waist circumference and waist/hip ratio) in health and disease. We also sought to determine if aortic stiffness was correlated with body size, independent of BP. METHODS: BMI, brachial BP and estimated central SBP (by SphygmoCor and radial P2) were recorded in controls (n=228), patients with diabetes (n=211), coronary artery disease (n=184) and end-stage kidney disease (n=68). Additional measures of waist circumference and arterial stiffness (aortic and brachial pulse wave velocity (PWV)) were recorded in a subgroup of 75 controls (aged 51 ± 12 years) who were carefully screened for factors affecting vascular function. RESULTS: BMI was associated with brachial (r=0.30; P<0.001) and central SBP (r=0.29; P<0.001) in the 228 controls, but not the patient populations (r<0.13; P>0.15 for all comparisons). In the control subgroup, waist circumference was also significantly correlated with brachial SBP (r=0.29; P=0.01), but not central SBP (r=0.22; P=0.07). Independent predictors of aortic PWV in the control subgroup were brachial SBP (ß=0.43; P<0.001), age (ß=0.37; P<0.001), waist circumference (ß=0.39; P=0.02) and female sex (ß=-0.24; P=0.03), but not BMI. CONCLUSION: In health, there are parallel increases in central and brachial SBP as BMI increases, but these relationships are not observed in the presence of chronic disease. Moreover, BP is a stronger correlate of arterial stiffness than body size.

Protein intake during gestation affects postnatal bovine skeletal muscle growth and relative expression of IGF1, IGF1R, IGF2 and IGF2R.

Expression of insulin-like growth factor (IGF)1 and IGF2 and their receptor (IGF1R and IGF2R) mRNA in fetal skeletal muscle are changed by variations in maternal nutrient intake. The persistence of these effects into postnatal life and their association with phenotype in beef cattle is unknown. Here we report that the cross-sectional areas of longissimus dorsi and semitendinosus (ST) muscles were greater for mature male progeny born to heifers fed low protein diets (70% vs. 240% of recommended) during the first trimester. In ST, this was accompanied by greater IGF1, IGF2 and IGF2R mRNA at 680 d. Females exposed to low protein diets during the first trimester had decreased IGF2 mRNA in ST at 680 d, however this did not result in an effect to phenotype. Exposure to low protein diets during the second trimester increased IGF1R mRNA in ST of all progeny at 680 d. Changes to expression of IGF genes in progeny skeletal muscle resulting from variations to maternal protein intake during gestation may have permanent and sex-specific effect on postnatal skeletal muscle growth.

Nutrient intake in the bovine during early and mid-gestation causes sex-specific changes in progeny plasma IGF-I, liveweight, height and carcass traits.

Fetal and postnatal growth are mediated by insulin-like growth factors (IGFs) and their binding proteins (IGFBPs). Maternal nutrient intake during gestation can program the postnatal IGF-axis. This may have significant economic implications for beef cattle production. We investigated the effect of high (H=240%) and low (L=70%) levels of recommended daily crude protein (CP) intake for heifers during the first and second trimesters of gestation in a two-by-two factorial design on progeny (n=68) plasma IGF-I, IGF-II, total IGFBP (tIGFBP), postnatal growth and carcass traits. Calves were heavier at birth following high CP diets during the second trimester (P=0.03) and this persisted to 29d. Plasma IGF-I concentrations of males were greater for HL compared to LL (P<0.01) and HH (P>0.04) from 29 to 657d, and for LH compared to LL from 29 until 379d (P=0.02). Exposure to low CP diets during the first trimester resulted in heavier males from 191d onwards (P=0.04) but a tendency for lighter females from 552d onwards (P=0.07) that had lighter carcass weights (P=0.04). Longissimus dorsi cross-sectional area of all carcasses was greater following exposure to low CP diets during the second trimester (P=0.04). Heifer nutrient intake during the first and second trimesters causes persistent and sex-specific programming of progeny plasma IGF-I, postnatal liveweight and carcass weight. Refining heifer nutritional programs during early gestation may optimize production objectives in progeny.

Dietary manipulation of Bos indicusxheifers during gestation affects the prepubertal reproductive development of their bull calves.

We determined the influence of nutritional protein and energy during the first and second trimesters of pregnancy in composite beef heifers on prepubertal reproductive parameters of their male calves. At artificial insemination, heifers were stratified by weight within each composite genotype into 4 treatment groups: High/High (HH=250% crude protein (CP) and 243% metabolisable energy (ME) for first and 229% CP and 228% ME for second trimester of pregnancy), High/Low (HL=250% CP and 243% ME for first trimester and 63% CP and 176% ME for second trimester) Low/High (LowH=75% CP and 199% ME for first trimester and 229% CP and 228% ME for second trimester) or Low/Low (LL=75% CP and 199% ME for first trimester and 63% CP and 176% ME for second trimester). At 5 months of age, male calves were castrated, and gonadotrophins and testosterone (pre- and post-GnRH challenge), IGF-I and leptin were measured along with testicular parameters. Lower maternal dietary protein and energy levels during gestation were associated with increased prepubertal FSH concentrations (P=0.03) and paired testicular volume (P=0.04) in male offspring. Serum LH (P<0.001) and FSH concentrations (P=0.04) were correlated with seminiferous tubule diameter. Testosterone concentrations were positively correlated with testis measures: paired testicular weight (P<0.001), volume (P=0.03) and seminiferous tubule diameter (P<0.001). Although leptin concentrations were associated with prepubertal age (P=0.04) and body weight (P=0.006), they were not associated with any of the measures of reproductive development, but insulin-like growth factor-I was associated with prepubertal FSH (P=0.005). In conclusion, prepubertal reproductive development of bulls may be affected by prenatal nutrition during early and mid gestation.

Heifer nutrition during early- and mid-pregnancy alters fetal growth trajectory and birth weight.

Maternal nutrient intake during gestation can alter fetal growth. Whilst this has been studied extensively in the sheep, less is known about effects in the bovine. Composite-breed beef heifers were allocated to either a high (H/-=76 MJ metabolisable energy (ME) and 1.4 kg crude protein (CP)) or low (L/-=62 MJ ME and 0.4 kg CP daily) nutritional treatment at artificial insemination. Half of each nutritional group changed to an opposite nutritional group at the end of the first trimester (-/H=82 MJ ME and 1.4 kg CP; -/L=62 MJ ME and 0.4 kg CP daily), resulting in 4 treatment groups: HH (n=16); HL (n=19); LH (n=17); LL (n=19). During the third trimester all heifers were fed the same diets. Fetuses were measured at 4-weekly intervals beginning at day 39 of gestation. Calves were also measured at birth for physical body variables. Low maternal nutrient intake was associated with decreased crown-rump length at day 39 (P<0.01) and increased thoracic diameter at day 95 (P<0.01). Umbilical cord diameter was reduced in L/- fetuses in the first trimester (P<0.05) but was greater in -/L fetuses in the second trimester compared to their respective H counterparts (P<0.05). Calf birth weight was decreased in association with -/L maternal diets (P<0.05). In conclusion, fetal development of cattle may be affected by maternal nutrition as early as day 39 of gestation. This may be followed by either compensatory fetal growth, or alternatively, preferential fetal tissue growth that is dependant upon maternal nutrition. Clearly, calf birth weight may be altered by maternal nutrition during mid-gestation.

Dystocia in 3-year-old beef heifers; relationship to maternal nutrient intake during early- and mid-gestation, pelvic area and hormonal indicators of placental function.

The influence of nutrition during the first and second trimesters of gestation on the occurrence of dystocia was investigated in 3-year-old composite-breed beef heifers. Heifers were allocated according to stratification by weight and genotype to either a high (H/-=76 MJ metabolisable energy (ME) and 1.4 kg crude protein (CP)), or low (L/-=62 MJ ME and 0.4 kg CP daily) nutritional treatment on the day of artificial insemination (day 0) to the same Senepol bull. Half of each nutritional group changed to an opposite nutritional group on day 93 of gestation (-/H=82 MJ ME and 1.4 kg CP; -/L=63 MJ ME and 0.4 kg CP daily), resulting in four treatment groups: HH (n=16); HL (n=19); LH (n=17); LL (n=19). From 180 days until calving all heifers were fed the same diets. Pelvic area measures were taken at heifer selection (-72 days) and at 117 days. Maternal circulating concentrations of estrone sulphate (ES), bovine placental lactogen (bPL), bovine pregnancy associated glycoprotein and progesterone were monitored throughout gestation. Heifers were observed continuously over the calving period and delivery type classified as being either eutocic or dystocic. The occurrence of dystocia was 14.1%. Increased calf birth weight increased the odds of occurrence of dystocia (odds ratio (OR)=1.40; 95% confidence interval (95% CI) 1.12-1.76; P<0.01). High diets in the second trimester were associated with heavier calves at birth (P=0.01). The mean pelvic area of eutocic heifers on -72 d, tended to be greater compared to that of dystocic heifers (P=0.08) such that a 1-cm(2) difference in pelvic area tended to decrease the risk of dystocia (OR=0.97; 95% CI 0.93-1.01; P=0.09). Longer gestation length was associated with an increased risk of dystocia (P=0.03). ES (P=0.04) and bPL (P=0.09) at calving were positively associated with the risk of dystocia. In conclusion, the current study demonstrates (a) that pelvic area measurement at selection in 3-year-old Bos indicusxBos taurus heifers may be useful for identifying heifers at an increased risk of dystocia and (b) increased ES and bPL concentrations at calving are associated with increased risk of dystocia. Pelvic area measurements obtained prior to conception remain valid in their assessment of the relationship between pelvic area and likelihood of dystocia occurring in the event of changing maternal nutrient intake during gestation. This is an important finding given maternal diets high in protein and energy during the second trimester of gestation increased calf birth weight and calf birth weight was associated with an increase in the occurrence of dystocia in heifers calving as 3-year olds.

Influences of diet during gestation on potential postpartum reproductive performance and milk production of beef heifers.

The influences of nutritional protein and energy during early and mid pregnancy on milk production and postpartum reproductive parameters were determined in 70 beef heifers of two composite breeds (Bos indicus X Bos taurus). At artificial insemination (AI), heifers were divided into four dietary treatment groups identified by the level of protein, and to a lesser extent energy, fed during the first and second trimesters: high/high (HH), high/low (HL), low/high (LH), and low/low (LL). Milk production was lower in the heifers receiving high treatment in first trimester than that in heifers receiving the low treatment (P=0.01). Milk production was negatively associated with dam body condition score (BCS; P=0.01), nonesterified fatty acids (P=0.001), and leptin (P=0.02) and positively associated with urea (P<0.001) concentrations during lactation. Increased dietary protein in the first trimester increased or decreased concentrations of colostral protein dependent upon genotype (P=0.03). Colostral protein was positively associated with bovine pregnancy associated glycoprotein from late gestation (P=0.007). Milk fat was negatively associated with BCS (P=0.007) and influenced by genotype (P=0.003). Dietary treatment did not affect the postpartum reproductive performance of beef heifers. Gestation length (P<0.001) and the postpartum interval to first estrus (PPI; P=0.02) were positively associated with calf size. Placental size was negatively associated with placental expulsion time (P<0.01). Prepartum BCS of the heifers was negatively associated with PPI (P=0.01). Overall, high levels of nutrition during early gestation are detrimental to milk production in beef heifers.

Dietary protein during gestation affects maternal insulin-like growth factor, insulin-like growth factor binding protein, leptin concentrations, and fetal growth in heifers.

The influence of supplemental protein during gestation on maternal hormones and fetal growth was determined in composite beef heifers. At AI, 118 heifers were stratified by BW within each composite genotype (BeefX = 1/2 Senepol, 1/4 Brahman, 1/8 Charolais, 1/8 Red Angus and CBX = 1/2 Senepol, 1/4 Brahman, 1/4 Charolais) into 4 treatment groups: high high (HH = 1.4 kg CP/d for first and second trimesters of gestation), high low (HL = 1.4 kg of CP/d for first trimester and 0.4 kg of CP/d for second trimester), low high (lowH = 0.4 kg CP/d for first trimester and 1.4 kg of CP/d and for second trimester), or low low (LL = 0.4 kg CP/d for first and second trimesters). Maternal plasma IGF-I and -II, total IGFBP, and leptin concentrations were determined at 14 d before AI and at d 28, 82, 179, and 271 post-AI (mean gestation length 286 d), and leptin concentrations were also determined at calving. Increased dietary protein increased maternal plasma IGF-I (P < 0.001 on d 28, 82, and 179), IGF-II (P = 0.01 on d 82; P = 0.04 on d 271), and total IGFBP (P = 0.002 on d 82; P = 0.005 on d 179; P = 0.03 on d 271). Maternal plasma IGF-I at d 271 was negatively associated with calf crown-rump length at birth (P = 0.003). BeefX had greater birth weight calves (P = 0.01), greater IGF-II (P < 0.001), increased ratios of IGF-I:total IGFBP (P = 0.008) and IGF-II:total IGFBP (P < 0.001), and reduced total IGFBP compared with CBX (P = 0.02). Increased dietary protein during second trimester increased maternal plasma leptin at calving (P = 0.005). Maternal plasma leptin near term was positively associated with heifer BCS (P = 0.02) and with calf birth weight (P = 0.04), and at calving was positively associated with heifer age at AI (P = 0.02). These findings suggest that maternal dietary protein, age, and genotype influence plasma concentrations of metabolic hormones and fetal growth in Bos indicus-influenced heifers.

Dietary manipulation of Bos indicus x heifers during gestation affects the reproductive development of their heifer calves.

The effect of nutrition during the first and second trimesters of pregnancy in composite beef heifers on reproductive parameters of their female calves was determined in the present study. At artificial insemination, heifers were assigned to one of four treatment groups (i.e. HH, HL, LowH and LL) depending on the level of crude protein intake (H = high; L = low) for first and second trimesters of pregnancy. Gonadotrophin concentrations and ovarian parameters were measured in their female calves at 5 and 23 months of age. Crude protein intake was positively associated with dam plasma urea (P < 0.001). The density of healthy follicles in heifers at the time of death was negatively correlated with dam plasma urea at Day 179 (P = 0.009). Heifers from LowH dams had a smaller-sized prepubertal largest ovarian follicle (P = 0.03) and lower densities of primordial and primary follicles (P = 0.02) and healthy antral follicles (P = 0.009) when they were killed. There was a positive correlation between plasma FSH concentrations at 5 and 23 months of age (P = 0.02), as well as between the sizes of the largest ovarian follicles at 6 and 23 months of age (P = 0.01). In conclusion, the reproductive development of heifers may be affected by prenatal nutrition during early and mid-gestation.

Dietary protein during gestation affects placental development in heifers.

The influence of nutritional protein during the first and second trimesters of pregnancy on placental measures at term and caruncle numbers in the uteri of adult offspring was determined in composite beef heifers. At artificial insemination (AI), heifers were divided by weight and composite genotype into four dietary treatment groups, identified by the level of protein components fed during the first and second trimesters: high/high (HH), high/low (HL), low/high (LH), low/low (LL). Expelled placentas were collected and weighed, and cotyledons were dissected, counted, weighed, and measured. Uteri from mature female offspring were dissected at slaughter and caruncles counted. The number of cotyledons in the expelled placenta was increased by high dietary protein in the second trimester (P=0.02) and varied with genotype (P=0.03). Placental weight was influenced by maternal undernutrition during early gestation dependent on dam genotype (P=0.001). Placental efficiency, as determined by calf weight:placental weight, increased with dam age (P=0.03). Calf birth weight was closely associated with placental weight (P=0.002) and cotyledonary weight (P=0.001) and surface area (P=0.04), but not with the number of cotyledons. Leptin concentrations during early (R=-0.29) and late gestation (R=-0.25) correlated with placental weight, and Insulin-like growth factor binding proteins throughout gestation correlated with the number of cotyledons (R=-0.28 to-0.33). The number of uterine caruncles in the nonpregnant adult offspring did not correlate with the dam's genotype, nutrition treatment, or cotyledon number in the expelled placenta.

Dietary protein during gestation affects circulating indicators of placental function and fetal development in heifers.

The influences of nutritional protein during the first and second trimesters of pregnancy on placental hormones and fetal growth were determined in composite beef heifers. At artificial insemination, heifers were stratified by weight within each composite genotype into 4 treatment groups: High High (HH=1.4kg crude protein (CP)/day for first and second trimesters of gestation; n=16), High Low (HL=1.4kg CP/day for first trimester and 0.4kg CP/day for second trimester; n=19), Low High (LH=0.4kg CP/day for first trimester and 1.4kg CP/day for second trimester; n=17) or Low Low (LL=0.4kg CP/day for first and second trimesters; n=19). Maternal plasma bovine pregnancy associated glycoprotein (bPAG) and progesterone (P4) were determined at gestation day (gd) 28, 82, 179 and 271 (mean gestation length 286 days) in addition to P4 at term. Estrone sulphate (ES) and bovine placental lactogen (bPL) concentrations were measured at gd 124, 179, 236 and 271 and at term in addition to ES at gd 82. Low dietary protein increased placental function as indicated by increased bPAG (P<0.001) and ES (P=0.02) concentrations in first trimester and increased bPL concentrations (P=0.01) in the second trimester of gestation. In the third trimester, when dietary treatment had ceased, placental function was no longer associated with previous dietary treatments. Dam genotype affected placental function as measured by bPL (P<0.001) and ES concentrations (P=0.02). Calf gender, heifer age and maternal insulin-like growth factor (IGF)-I, -II and leptin did not affect hormonal indicators or circulating markers of placental function. Enhanced placental function during the third trimester, as measured by ES, was associated with increased calf birth weight (P=0.003).

Variability in adherence to an unsupervised exercise prescription in obese women.

OBJECTIVE: To measure adherence to a specific exercise prescription (1500 kcal week(-1)) by objectively quantifying unsupervised exercise energy expenditure (ExEE) in obese women. DESIGN: The 16-week lifestyle intervention consisted of weekly meetings with research staff and promotion of increased ExEE (1500 kcal week(-1)) and a decreased dietary intake (-500 kcal day(-1)). PARTICIPANTS: Twenty-nine obese females (body mass index=36.8+/-5.0 kg m(-2), body fat=49.6+/-3.7%) from a hospital-based lifestyle intervention were included in the analysis. MEASUREMENTS: ExEE was estimated and monitored weekly using heart rate monitoring, and body composition was measured before and after the intervention by dual-energy X-ray absorptiometry. RESULTS: Free-living adherence to the exercise prescription was variable and, on average, modest such that 14% achieved 1500 kcal week(-1), and the average weekly ExEE (768 kcal week(-1)) represented 51.2% of the total amount prescribed. ExEE was correlated with changes in body weight (r=0.65, P<0.001) and fat mass (r=0.65, P<0.001). Achievement of a 5% weight loss target was dependent on the achievement of an ExEE level of 1000 kcal week(-1) (P<0.001). Exercise 'adherers' (>1000 kcal week(-1)) lost more weight (-9.9 vs -4.1 kg), more fat mass (-6.8 vs -3.0 kg) and more waist circumference (-9.8 vs -5.6 cm) when compared to 'non-adherers' (<1000 kcal week(-1)). DISCUSSION: Exercise is an integral component of lifestyle interventions aimed at reducing obesity and its complications. However, without accurate and objective measures of ExEE, it is difficult for relationships between exercise and health outcomes to be elucidated. The present study suggests an alternative to self-report to increase the confidence with which conclusions are drawn regarding the role of exercise within lifestyle interventions.

Effect of saline acclimation on body water and sodium compartmentalization in Pekin ducks (Anas platyrhynchos).

The compartmentalization of body fluids was measured in individual Pekin ducks ( Anas platyrhynchos) drinking freshwater and after sequential acclimation to 300 mM NaCl and 400 mM NaCl. Total body water, extracellular fluid volume, plasma volume and exchangeable sodium pool were measured using (3)H(2)O, [(14)C]-polyethylene glycol, Evans Blue dye, and (22)Na dilution, respectively. Following acclimation to 300 mM NaCl, body mass decreased, but total body water and total exchangeable sodium pool were unaltered. Na and water were redistributed from the extracellular fluid (interstitial fluid) compartment into the intracellular fluid compartment. Following further acclimation to 400 mM NaCl, body mass, total body water and intracellular fluid volume decreased, but exchangeable sodium pool and extracellular fluid volume were unchanged. Our results suggested that, when Pekin ducks drink high but tolerable salinities, they maintain total body water, but redistribute Na(+) and water from interstitial fluid to the intracellular fluid compartment. When stressed beyond their ability to maintain total body water, they lose water from the intracellular fluid.

A reappraisal of a modified through-knee amputation in patients with peripheral vascular disease.

BACKGROUND: Through-knee amputation provides a longer lever arm and improved muscle control of the limb compared with above-knee amputation. Through-knee amputation also allows use of a total end-bearing prosthesis, which avoids the ischial pressure and suspension belts required of the above-knee amputation prosthesis. Several reports in the European literature tout the superiority of the through-knee amputation over the above-knee amputation in the patient with vascular disease. Through-knee amputation has received little attention in the United States, however, owing to the belief that the long flaps necessary to close a standard through-knee amputation are associated with an unacceptable rate of wound problems and offer no functional ambulatory advantage to above-knee amputation. We reviewed our experience with a modified technique of through-knee amputation in a group of patients with severe lower extremity ischemia who were not candidates for below-knee amputation to determine the incidence of wound complications and their functional outcome. METHODS: Since 1996, 12 patients with severe lower extremity arterial insufficiency have undergone through-knee amputation utilizing a technique designed to limit flap length and facilitate the fit of a suction prosthesis. Two patients died of myocardial infarction in the immediate postoperative period and were excluded from the study. In the remaining 10 patients (1 man, 9 women; mean age 63 years (range 40 to 86), the below-knee amputation level was precluded because of gangrene or nonhealing wounds of the mid leg in 5 patients, failure of a previous below-knee amputation attempt in 4 patients, and severe ischemia that would compromise below-knee amputation healing in 1 patient. Nine patients had at least one failed vascular reconstruction procedure. RESULTS: Mean follow-up is 25 months (range 6 to 41). Six (60%) patients had primary healing of their amputations. Two (20%) patients had delayed healing (6 weeks and 8 weeks). Two (20%) patients developed wound infections, which required amputation revision to the above-knee level. Seven (70%) patients were fitted with a suction socket prosthesis and are fully ambulatory. One patient healed but has not ambulated because of ischemia and subsequent ulceration of the contralateral limb. CONCLUSIONS: These data show that through-knee amputation is associated with an acceptable primary healing rate (80%) and satisfactory functional outcomes (70% ambulation) in a high-risk vascular population. The functional advantages of through-knee amputation over above-knee amputation make it the preferred alternative for patients with vascular disease.

Intravascular ultrasound assessment of iliac stent procedures.

PURPOSE: To determine whether intravascular ultrasound (IVUS) is more sensitive in identifying incomplete stent deployment or mechanical disruption compared to angiography. METHODS: Over a 9-month period, 44 patients (25 men; mean age 63 years, range 36-88) treated for common or external iliac artery stenoses with balloon angioplasty and stenting underwent IVUS interrogation following completion arteriography. RESULTS: One hundred nine stents were deployed in the 44 patients. Of these, 29 (27%) stents (in 45% of patients) were found by IVUS to be incompletely deployed or to have an associated mechanical disruption despite a normal completion arteriogram. Further treatment (repeat dilation or additional stenting) was performed in 28 cases; 1 hemodynamically insignificant dissection was not treated. Twenty-six (93%) of these interventions were successful as determined by IVUS; 2 underexpanded stents did not respond to redilation. CONCLUSIONS: Incomplete stent deployment or mechanical problems associated with stenting were common in this study, occurring in nearly half of the patients. IVUS has clinical utility in identifying incomplete deployment or mechanical problems in stents with an increased sensitivity compared to contrast angiography.

Concomitant renal revascularization with aortic surgery: are the risks of combined procedures justified?

Indications for concomitant renal revascularization during aortic surgery are not well established. Higher mortality and poorer results are often cited. To examine this, all combined aortic and renal revascularization procedures from August 1992 until May 1998 were reviewed. Of 2003 major arterial reconstructions performed on the Vascular Teaching Service, 45 patients (2%) underwent renal revascularization. Of these 31 patients (69%) had combined aortic and renal procedures. Aortic pathology in these 31 patients (54% male, 94% white, median age 64 years) included arterial occlusive disease (n = 21; 47%), abdominal aortic aneurysm (n = 6; 13%), and thoracoabdominal aortic aneurysm (n = 4; 9%). In all 31 cases the patient presented because of the aortic pathology. Indications for concomitant renal revascularization included renovascular hypertension (n = 21; 68%) and preservation of renal function (n = 10; 32%). Renal revascularization procedures included transaortic endarterectomy (n = 23; 74%), renal bypass (n = 7; 23%), and both bypass and endarterectomy (n = 1; 3%). Seven (22%) complications and two (6%) deaths (both patients operated on for renal salvage) occurred perioperatively. Complications included wound infection (n = 2; 6%), postoperative bleeding (n = 1; 3%), respiratory failure (n = 1; 3%), deep venous thrombosis (n = 1; 3%), cerebrovascular accident (n = 1; 3%), and pseudomembranous enterocolitis (n = 1; 3%). All patients either were cured of their hypertension (n = 5; 24%) or were improved (n = 16; 76%) at 3 months. No patient to date operated on for renal salvage progressed to chronic hemodialysis, but mortality was higher after renal revascularization for renal salvage versus hypertension (20% vs. 0; P = 0.034). There was no significant difference in mortality between the combined aortic/renal procedures versus aortic procedures alone. Despite adding complexity, renal revascularization in patients undergoing aortic surgery appears relatively safe and effective. These data favor an aggressive approach toward renal revascularization in selected patients needing aortic surgery.