Pre-surgery Baseline Research Articles

Assessment of Selenium in Roux-en-Y Gastric Bypass and Gastric Banding Surgery

Until recently, there was limited documented data on both dietary and serum selenium deficiency in bariatric surgery. We performed an evaluation of selenium intake and both serum selenium and glutathione peroxidase (GTP; as a functional measurement of selenium) before and after roux-en-Y (RNY) gastric bypass and gastric banding surgery. The endpoints obtained from the subjects included dietary intake of selenium and vitamins E and C, as well as serum levels of selenium, GTP and vitamins E. These were analyzed at pre-surgery (baseline) and 3 and 12 months post surgery. Dietary deficiencies in selenium intake (38.2 % recommended daily allowance) were noted at 3 months, but not baseline or 12 months, in the gastric bypass group. No dietary deficiencies were noted in the lap band group. For both surgeries, there was a significant reduction from baseline to 3 months in both serum selenium and GTP levels (p = 0.033 and 0.0033 respectively). The serum selenium levels and GTP levels both trended back toward baseline values by 12 months without concomitant selenium supplementation. Mean GTP levels were below normal at all three time points while mean serum selenium levels were all at or above normal. This study shows that RNY gastric bypass and laparoscopic adjustable gastric banding procedures, and accompanying dietary restrictions, increases the risk for disturbances of selenium and GTP homeostasis. Consideration for selenium supplementation at higher levels than the current RDA of 55 mcg daily during the first 3 months and perhaps longer should be studied further.

Long-Term Evaluation of a Phase 1 Study of AADC Gene Therapy for Parkinson's Disease

We report the results of a long-term follow-up of subjects in a phase 1 study of AAV2-hAADC (adeno-associated virus type 2-human aromatic L-amino acid decarboxylase) gene therapy for the treatment of Parkinson's disease (PD). Ten patients with moderately advanced PD received bilateral putaminal infusions of either a low or a high dose of AAV2-hAADC vector. An annual positron emission tomography (PET) imaging with [(18)F]fluoro-L-m-tyrosine tracer was used for evaluation of AADC expression, and a standard clinical rating scale [Unified Parkinson's Disease Rating Scale (UPDRS)] was used to assess effect. Our previous analysis of the 6-month data suggested that this treatment was acutely safe and well tolerated. We found that the elevated PET signal observed in the first 12 months persisted over 4 years in both dose groups. A significantly increased PET value compared with the presurgery baseline was maintained over the 4-year monitoring period. The UPDRS in all patients off medication for 12 hr improved in the first 12 months, but displayed a slow deterioration in subsequent years. This analysis demonstrates that apparent efficacy continues through later years with an acceptable safety profile. These data indicate stable transgene expression over 4 years after vector delivery and continued safety, but emphasize the need for a controlled efficacy trial and the use of a higher vector dose.

Right Ventricular Outflow Tract Repair with a Cardiac Biologic Scaffold

Background: Surgical reconstruction of congenital heart defects is often limited by the nonresorbable material used to approximate normal anatomy. In contrast, biologic scaffold materials composed of resorbable non-cross-linked extracellular matrix (ECM) have been used for tissue reconstruction of multiple organs and are replaced by host tissue. Preparation of whole organ ECM by decellularization through vascular perfusion can maintain much of the native three-dimensional (3D) structure, strength, and tissue-specific composition. A 3D cardiac ECM (C-ECM) biologic scaffold material would logically have structural and functional advantages over materials such as Dacron™ for myocardial repair, but the in vivo remodeling characteristics of C-ECM have not been investigated to date. Methods and Results: A porcine C-ECM patch or Dacron patch was used to reconstruct a full-thickness right ventricular outflow tract (RVOT) defect in a rat model with end points of structural remodeling function at 16 weeks. The Dacron patch was encapsulated by dense fibrous tissue and showed little cellular infiltration. Echocardiographic analysis showed that the right ventricle of the hearts patched with Dacron were dilated at 16 weeks compared to presurgery baseline values. The C-ECM patch remodeled into dense, cellular connective tissue with scattered small islands of cardiomyocytes. The hearts patched with C-ECM showed no difference in the size or function of the ventricles as compared to baseline values at both 4 and 16 weeks. Conclusions: The C-ECM patch was associated with better functional and histomorphological outcomes compared to the Dacron patch in this rat model of RVOT reconstruction.

Delivery of sry1, but not sry2, to the kidney increases blood pressure and sns indices in normotensive wky rats

BackgroundOur laboratory has shown that a locus on the SHR Y chromosome increases blood pressure (BP) in the SHR rat and in WKY rats with the SHR Y chromosome (SHR/y rat). A candidate for this Y chromosome hypertension locus is Sry, a gene that encodes a transcription factor responsible for testes determination. The SHR Y chromosome has six divergent Sry loci. The following study examined if exogenous Sry1 or Sry2 delivered to the kidney would elevate renal tyrosine hydroxylase, renal catecholamines, plasma catecholamines and telemetered BP over a 28 day period. We delivered 50 μg of either the expression construct Sry1/pcDNA 3.1, Sry2/pcDNA 3.1, or control vector into the medulla of the left kidney of normotensive WKY rats by electroporation. Weekly air stress was performed to determine BP responsiveness. Separate groups of animals were tested for renal function and plasma hormone patterns and pharmacological intervention using alpha adrenergic receptor blockade. Pre-surgery baseline and weekly blood samples were taken from Sry1 electroporated and control vector males for plasma renin, aldosterone, and corticosterone. BP was measured by telemetry and tyrosine hydroxylase and catecholamines by HPLC with electrochemical detection.ResultsIn the animals receiving the Sry1 plasmid there were significant increases after 21 days in resting plasma norepinephrine (NE, 27%) and renal tyrosine hydroxylase content (41%, p < .05) compared to controls. BP was higher in animals electroporated with Sry1 (143 mmHg, p < .05) compared to controls (125 mmHg) between 2–4 weeks. Also the pressor response to air stress was significantly elevated in males electroporated with Sry1 (41 mmHg) compared to controls (28 mmHg, p < .001). Sry2 did not elevate BP or SNS indices and further tests were not done. The hormone profiles for plasma renin, aldosterone, and corticosterone between electroporated Sry1 and control vector males showed no significant differences over the 28 day period. Alpha adrenergic receptor blockade prevented the air stress pressor response in both strains. Urinary dopamine significantly increased after 7 days post Sry electroporation.ConclusionThese results are consistent with a role for Sry1 in increasing BP by directly or indirectly activating renal sympathetic nervous system activity.

Effect of combining dexmedetomidine and morphine for intravenous patient-controlled analgesia

BackgroundPerioperative use of dexmedetomidine is associated with reduction in postoperative analgesic requirements. This study examined whether dexmedetomidine added to i.v. patient-controlled analgesia (PCA) morphine could improve analgesia while reducing opioid-related side-effects. MethodsIn this double-blinded, randomized, controlled study, 100 women undergoing abdominal total hysterectomy were allocated to receive either morphine 1 mg ml−1 alone (Group M) or morphine 1 mg ml−1 plus dexmedetomidine 5 μg ml−1 (Group D) for postoperative i.v. PCA, which was programmed to deliver 1 ml per demand with a 5 min lockout interval and no background infusion. Cumulative PCA requirements, pain intensities, cardiovascular and respiratory variables, and PCA-related adverse events were recorded for 24 h after operation. ResultsCompared with Group M, patients in Group D required 29% less morphine during the 0–24 h postoperative period and reported significantly lower pain levels from the second postoperative hour onwards and throughout the study. Whereas levels of sedation were similar between the groups at each observational time point, decreases in heart rate and mean blood pressure from presurgery baseline at 1, 2, and 4 h after operation were significantly greater in Group D (by a range of 5–7 beats min−1 and 10–13%, respectively). The 4–24 h incidence of nausea was significantly lower in Group D (34% vs 56.3%, P<0.05). There was no bradycardia, hypotension, oversedation, or respiratory depression. ConclusionsThe addition of dexmedetomidine to i.v. PCA morphine resulted in superior analgesia, significant morphine sparing, less morphine-induced nausea, and was devoid of additional sedation and untoward haemodynamic changes.

Night eating status and influence on body weight, body image, hunger, and cortisol pre-and post-Roux-en-Y Gastric Bypass (RYGB) surgery

Night Eating Syndrome is a common disorder in severely obese individuals and may be associated with hypothalamic pituitary adrenal (HPA) axis dysregulation. This study compared night eaters (NE) and comparably obese controls (C) pre- and post-Roux-en- Y Gastric Bypass surgery at 2 and 5 months, following an overnight fast on hormonal measures associated with HPA axis and related appetite and psychological measures. There were 24 (10 NE, 14 C) clinically severely obese participants (body mass index =47.0+/-8.4 SD). At pre-surgery baseline, afternoon fasting hunger ratings differed significantly and were lower for NE than for C (p=0.01). Eight of the participants (4 NE, 4C) returned for all 3 study visits. At 5 months post-surgery, NE and C did not differ in weight loss, reductions in waist circumference, insulin levels, and insulin resistance (homeostasis model assessment). However, NE as compared to C, did not improve in self ratings of body image (p<0.05), and had significant increases in fasting afternoon cortisol levels 5 months after surgery (p=0.01).

Poster 136: Measurement Properties of Circulating Interleukin-6 and Oncostatin-M For Quantifying Musculoskeletal Injury

Objective: This study was performed to examine changes in serum concentrations of interleukin-6 (IL-6) and oncostatin M following total knee replacement (TKR) surgery in order to examine biomarker measurement properties including sensitivity to injury and variability across individuals in time to peak concentrations. Design: Repeated measures, measurement evaluation. Setting: Orthopedic surgery clinic in a teaching hospital in Hamilton, ON, Canada. Participants: 4 men and 10 women undergoing unilateral TKR. Interventions: Not applicable. Main Outcome Measures: Serial blood samples were taken in the preoperative waiting areas, immediately after surgery, at 6, 12, and 24 hours, and then at 24-hour intervals to 7 days. IL-6 and oncostatin-M concentrations were measured by enzyme-linked immunosorbent assay. Data on individual subjects were plotted over time to visualize the injury response curves. Results: Mean peak IL-6 (651pg/ml; range, 96–2750) significantly exceeded mean presurgery baseline (2pg/ml; range, 0–22). There were no sex differences in baseline or peak IL-6 concentrations. Time to peak ranged between 12 to 48 hours across individuals. There were no sex differences in the timing of the peak. The time window remained the same for low IL-6 secreters (peak below 130pg/ml), moderate secreters (peak 131–400pg/ml), and high secreters (peak >400pg/ml). There was no serum Oncostatin M injury response detectable in any subject. Conclusions: IL-6 has good sensitivity to the state of injury following TKR. The variable time course of IL-6 indicates potential problems with the previous comparison of surgical procedures at common time points (eg, 24h) and necessitates serial measures within 12 to 48 hours to estimate the peak. Oncostatin M did not provide a biochemical index of musculoskeletal injury.

Muscle strength quantification in small animals: A new transcutaneous technique in rabbits

The objective of this study was to develop a new, simple, and noninvasive technique to measure the force produced by dorsi-flexion of the foot in small animals. In addition, this study aimed to quantitatively describe changes in muscle and soft tissue structures using histomorphometry. The recovery of the dorsi-flexing muscles in the tibialis anterior compartment in New Zealand White rabbits was evaluated after musculoskeletal trauma by measuring isometric contractions after submaximal transcutaneous electrical stimulation of the peroneal nerve. The trauma included muscle and bone trauma that was treated with limb shortening followed by distraction osteogenesis. Muscle contractions were initiated at an amplitude of 5.1 mA for a duration of 2.56 ms at intervals of 50 ms. Based on consecutive measurements of the force on days 5, 10, 15, 20, 25, and 30 postsurgery, a positive trend in recovery of the stimulated force produced by dorsi-flexion of the foot was observed. The muscle strength at 30 days postsurgery was compared to that measured presurgery (baseline): 55% of the animals had dorsi-flexion strength that was 60% below that of the presurgery baseline muscle strength; 36% of the animals had dorsi-flexion strength that was greater than 60% of the baseline measure, indicating that there was a significant decrease in force produced by dorsi-flexion of the foot after trauma on all testing days (p < 0.01) and that a severe muscular injury was set with limited recovery. This technique provides a new option for examining muscle regeneration and rehabilitation in small animals.

Urinary Incontinence After Radical Prostatectomy

Incontinence after radical prostatectomy for early stage prostate cancer can significantly affect quality of life. Identification of risk factors preoperatively would enable clinicians to counsel men and their partners about the risk of incontinence following surgery. We conducted a population-based study to identify subjective and objective preoperative factors, other than PSA and Gleason score, that may predict urinary incontinence following radical prostatectomy. Men booked for radical prostatectomy at 2 sites in Alberta were enrolled prospectively. Assessment was completed 2 weeks prior to surgery and included the International Prostate Symptom Score (IPSS) with a single quality-of-life (QOL) question, 24-hour pad test, and bladder diary. These parameters were repeated at 3 and 12 months postoperatively. A model predicting incontinence was developed using stepwise multivariable logistic regression analysis. Incontinence was defined as more than 8 g of urine loss on 24-hour pad test. A total of 245 patients from 2 centers were enrolled; 228 (93%) completed data collection up to 12 months postsurgery. At the baseline preoperative assessment, 4% (10/228) of subjects had > or = 8 g of urine loss on 24-hour pad test, although these and all other subjects described complete continence. At 3 months postop, 43% had > or = 8 g on 24-hour pad testing (our definition of incontinence) (median 31 g, range 8.3-1654 g, SD 219.12); at 12 months, 15% had more than 8 g of urine loss on pad test (median 21.0 g, range 8.1-3380 g, SD 578.0). For all subjects, mean IPSS and the single QOL scores at baseline (7.4 and 1.5) did not change significantly at 3 months (7.2 and 2.5), but both were lower than or equal to baseline at 12 months (5.4 and 1.5). The IPSS was predictive of incontinence at 3 months, but not at 12 months. Bladder diary did not correlate with IPSS. Risk factors affecting continence at 12 months were preoperative urine loss > or = 8 g, previous transurethral resection of prostate (TURP), and age greater than 65 years. Our results support previous research on risk factors for incontinence after radical prostatectomy and add to the current data by having presurgery (baseline) measures. Interestingly, a small percentage of men (4%) who reported complete continence were incontinent preoperatively, based on our definition of > or = 8 g weight gain on 24-hour pad test. Identified preoperative risk factors affecting continence were increasing age, baseline incontinence, and previous TURP. Mean IPSS was lower at 12 months than at baseline, suggesting that even mildly symptomatic men will improve after surgery. Men reported that regular contact with the continence research nurse provided a much-appreciated source of informed support as they recovered.

Early arm swelling after breast surgery: changes on both sides

Lymphedema is a common complication of treatment for breast cancer. However, little information is available describing changes in upper limb volumes in the early stages following surgery. Retrospective audit. Women who underwent unilateral mastectomy or axillary node removal for breast cancer at the Princess Alexandra Hospital, Brisbane, Australia. Circumferential measurements taken at 10 cm intervals from the ulnar styloid on each arm were converted to segmental volumes using the frustum approach. Pre-surgery baseline measures were taken by a physiotherapist at Preadmission Clinic at the Princess Alexandra Hospital. Follow-up measures were taken 6 weeks after surgery by Domiciliary Allied Health Acute Care and Rehabilitation Service physiotherapists in patients' homes. Limb segment volumes increased in the proximal upper limb segments at follow-up. The proportion of patients with a 10% or greater increase in volume in one or more segments of their upper limb were similar for ipsilateral (35%) and contralateral (32%) sides (to side of surgery), respectively. No significant interaction between time and arm (ipsilateral versus contralateral) was identified. These findings demonstrate that limb segment volume changes affect a greater proportion of patients during the first 6 weeks following surgery than previously recorded. They also indicate that flow of lymph from the side of surgery to the contralateral side may disperse lymph between sides during this early post-operative period. This has implications for how swelling is measured during this period and strategies to prevent onset of lymphedema.

Vergleichende Analyse des patientenzentrierten Outcome nach totalendoprothetischem Ersatz von Hüft- und Kniegelenk

The aim of the present study was a comparative investigation of the functional improvement reported by patients suffering from primary osteoarthritis of the knee or hip undergoing total joint replacement and assessed at 3 months. In a prospective, controlled clinical trial, 56 patients with primary osteoarthritis of the hip and 59 patients with primary osteoarthritis of the knee undergoing total joint replacement were assessed at two measuring times (day of admission = t1 and 3-month follow-up = t2) using the XSMFA-D (Extra Short Musculoskeletal Function Assessment Questionnaire--German version), WOMAC (Western Ontario and McMasters Universities) arthrosis index and FFb-H OA (Function Assessment Questionnaire Hannover Osteoarthritis). The statistical analysis included effect sizes as standardised response mean, t-test and covariance analysis. Both groups of patients demonstrated significant improvements of the musculoskeletal functions measured. The effect sizes between baseline scores and 3-month follow-up scores range from 0.4 to 2.0 and can be considered as large effects. The covariance analysis showed significant differences between patients with osteoarthritis of the hip and knee for almost every score examined. Patients with hip replacement showed large improvements. A significant influence of the presurgery baseline score on the 3-month score was found consistently. Further analysis showed that patients with medium or strong degrees of disability according to the Function index of the XSMFA-D showed the strongest effects of change at 3 months. However, their scores at t2 were less than the scores of the less disabled patients at t1. We conclude that patients with hip replacement show more improvement 3 months after the surgery than patients with knee replacement. Furthermore, it was seen that patients who were more disabled before surgery achieved more improvement than the less-disabled patients. However, they did not achieve the level of the less disabled patients. Thus, the recommendation that total joint replacement should be performed as late as possible should be reviewed.

Redox behavior of cytochrome oxidase and neurological prognosis in 66 patients who underwent thoracic aortic surgery.

Using near-infrared spectroscopy (NIRS), we have developed a new approach to the measurement of the redox state of cytochrome oxidase (cyt. ox.) in the brain. Our previous animal study showed that oxygen-dependent redox changes in cyt. ox. occur only when oxygen delivery is badly impaired. Therefore, in this study, we retrospectively examined the relationship between the redox behavior of cyt. ox. (measured by NIRS) during an operation and the neurological outcome in patients. We studied 66 patients undergoing thoracic aortic surgery with cardiopulmonary bypass. Cerebral oxygenation was monitored by NIRS, and relative values for the concentrations of oxy-Hb, deoxy-Hb, and the redox state of cyt. ox. in the brain were calculated using our developed algorithm. Retrospective assessment revealed three different types of cyt. ox. behavior: (1) no change (type-A) in 34 cases (51.5%), (2) a temporary reduction, with a subsequent return to the pre-surgery baseline level (type-B) in 29 cases (43.9%), or (3) a marked and prolonged reduction (type-C) in only three cases (4.5%). Nine of the 66 patients (13.6%; one type-A, five type-B, and all three type-C patients) showed evidence of postoperative brain injury (in the type-A patient, the injury proved to be localized and far from the monitoring site). The relationship between the occurrence of such an injury and the type of cyt. ox. behavior seen during the operation was highly significant (P<0.0001; chi-square test for independence). Our data suggest that the redox behavior of cyt. ox. during an operation is a good (though not perfect) predictor of postoperative cerebral outcome, and that overall tissue oxygen sufficiency can be confirmed by near-infrared measurement of cyt. ox.

Changes in septal regional ejection fraction early and late following coronary artery bypass grafting in patients without postoperative myocardial infarction

Changes in regional ejection fraction (rEF) of the interventricular septum following coronary artery bypass graft (CABG) surgery were examined using first-pass radionuclide ventriculography (RNVG) in patients without objective evidence of postoperative myocardial infarction (MI). One hundred and one patients had pre- (mean 6.3 days) and early postoperative (mean 8.7 days) RNVGs, and 60 of these patients had follow-up studies at 14-39 months (mean 27 months) postsurgery. Early post-CABG, mean rEF in the proximal septum was unchanged from the preoperative value (35.3%), with almost equal numbers of patients showing increased (n = 36), unchanged (n = 33) or decreased (n = 32) rEFs. In the distal septum, mean rEF increased from 47.1 to 50.7%, with more than twice as many patients having increased (n = 44) as decreased (n = 20) rEF. At late follow-up, proximal septum rEF in individual patients tended to revert to the presurgery baseline, with 72% (13/18) of regions with early decrease improved and 61% (14/23) of those with early improvement decreased. In the distal septum, rEF was less than early post-CABG in 76% (19/25) of patients with early improvement, while being improved in 27% (3/11) of those with early decrease in rEF. In the absence of MI, changes in rEF in the proximal septum early post-CABG tend to resolve over time. While global changes in cardiac systolic motion are the probable cause of many new post-CABG septal abnormalities, persistent septal dysfunction probably reflects effects of permanent damage as a result of the operative procedure.

Changes in septal regional ejection fraction early and late following coronary artery bypass grafting in patients without postoperative myocardial infarction

Summary Changes in regional ejection fraction (rEF) of the interventricular septum following coronary artery bypass graft (CABG) surgery were examined using first-pass radionuclide ventriculography (RNVG) in patients without objective evidence of postoperative myocardial infarction (MI). One hundred and one patients had pre- (mean 6.3 days) and early postoperative (mean 8.7 days) RNVGs, and 60 of these patients had follow-up studies at 14-39 months (mean 27 months) postsurgery. Early post-CABG, mean rEF in the proximal septum was unchanged from the preoperative value (35.3%), with almost equal numbers of patients showing increased (n = 36), unchanged (n = 33) or decreased (n = 32) rEFs. In the distal septum, mean rEF increased from 47.1 to 50.7%, with more than twice as many patients having increased (n = 44) as decreased (n = 20) rEF. At late follow-up, proximal septum rEF in individual patients tended to revert to the presurgery baseline, with 72% (13/18) of regions with early decrease improved and 61% (14/23) of those with early improvement decreased. In the distal septum, rEF was less than early post-CABG in 76% (19/25) of patients with early improvement, while being improved in 27% (3/11) of those with early decrease in rEF. In the absence of MI, changes in rEF in the proximal septum early post-CABG tend to resolve over time. While global changes in cardiac systolic motion are the probable cause of many new post-CABG septal abnormalities, persistent septal dysfunction probably reflects effects of permanent damage as a result of the operative procedure.

Assessment of bone remodeling in the temporomandibular joint by serial uptake measurement of technetium 99m-labeled methylene diphosphonate with a cadmium telluride probe

Regional uptake of technetium 99m-labeled methylene diphosphonate was measured serially over time to follow the healing course of surgically generated lesions, induced unilaterally in the condyles of beagles. A small portable cadmium telluride probe was used for radiation detection, with and without a gold collimator attached. Radioactivity was measured at six periarticular sites on both the operated and the contralateral control sides and expressed as a ratio with respect to a reference site over the sagittal suture. The use of a collimator was crucial to separate the activity associated with bone mineralization in the condylar head from that arising in the adjoining bones. The uptake in the condylar region increased 2 weeks after surgery and remained at a constant level above the presurgery baseline ( p < 0.05) until termination of the study (10 weeks). Postmortem histologic examinations confirmed the high bone turnover level by revealing newly formed bone as well as the presence of osteoclasts. The time course of nuclide uptake in the temporomandibular joint is different from the general pattern of rise and fall of activity displayed in other bones and indicates the persistence of bone remodeling processes during a prolonged period of at least 10 weeks.