Suprascapular nerve blockage for painful shoulder pathology - a systematic review and meta-analysis of treatment techniques

BACKGROUND

Suprascapular nerve blockade (SSNB) through injection (SSNBi) and/or pulsed radiofrequency (PRF) provide options for the management of painful shoulder pathology. Multiple techniques for delivery of SSNB are described but no consensus on optimal symptom control is available. This systematic review and meta-analysis aims to assess patient-focussed outcomes in SSNB and explore the impact of variation in the technical application of this treatment modality.

METHODS

MEDLINE, Embase and CINAHL were searched for case series, cohort studies and randomised control trials published from database inception until 28 January 2021. Articles reporting use of SSNBi or PRF for treatment of shoulder pain with a minimum 3 months follow-up were included. Patient-reported outcome measures (PROMs) were extracted and the pooled standardised mean difference (SMD), weighted by study size, was reported. Quality of methodology was assessed using Wylde's nonsummative four-point system.

FINDINGS

Of 758 references, 18 studies were included, totalling 704 SSNB. Average pain improvement at 3 months was 52.3%, with meta-analysis demonstrating a SMD of 2.37. Whereas SSNBi combined with PRF shows the greatest SMD of 2.75, this did not differ significantly from SSNBi or PRF when used as monotherapy. Location of treatment and the guidance technique used did not influence outcome.

CONCLUSION

SSNBi and PRF provide safe and effective treatment for shoulder pain, as judged by PROMs. This may be of particular value in aging or comorbid patients and with surgical restrictions during the COVID-19 pandemic. Regardless of technique, patients experience a marked improvement in pain that is maintained beyond 3 months.

Baseline bone turnover marker levels can predict change in bone mineral density during antiresorptive treatment in osteoporotic patients: the Copenhagen bone turnover marker study

Anti-resorptive osteoporosis treatment might be more effective in patients with high bone turnover. In this registry study including clinical data, high pre-treatment bone turnover measured with biochemical markers was correlated with higher bone mineral density increases. Bone turnover markers may be useful tools to identify patients benefitting most from anti-resorptive treatment.

INTRODUCTION

In randomized, controlled trials of bisphosphonates, high pre-treatment levels of bone turnover markers (BTM) were associated with a larger increase in bone mineral density (BMD). The purpose of this study was to examine this correlation in a real-world setting.

METHODS

In this registry-based cohort study of osteoporosis patients (n = 158) receiving antiresorptive therapy, the association between pre-treatment levels of plasma C-telopeptide of type I Collagen (CTX) and/or N-terminal propeptide of type I procollagen (PINP) and change in bone mineral density (BMD) at lumbar spine, total hip, and femoral neck upon treatment was examined. Patients were grouped according to their pre-treatment BTM levels, defined as values above and below the geometric mean for premenopausal women.

RESULTS

Pre-treatment CTX correlated with annual increase in total hip BMD, where patients with CTX above the geometric mean experienced a larger annual increase in BMD (p = 0.008) than patients with CTX below the geometric mean. The numerical pre-treatment level of CTX showed a similar correlation at all three skeletal sites (total hip (p = 0.03), femoral neck (p = 0.04), and lumbar spine (p = 0.0003)). A similar association was found for PINP where pre-treatment levels of PINP above the geometric mean correlated with a larger annual increase in BMD for total hip (p = 0.02) and lumbar spine (p = 0.006).

CONCLUSION

Measurement of pre-treatment BTM levels predicts osteoporosis patients' response to antiresorptive treatment. Patients with high pre-treatment levels of CTX and/or PINP benefit more from antiresorptive treatment with larger increases in BMD than patients with lower pre-treatment levels.

A digital holography ex situ measurement characterization of plasma-exposed surface erosion from an electrothermal arc source

Digital holography has been proposed to fulfill a need for an imaging diagnostic capable of in situ monitoring of surface erosion caused by plasma-material interaction in nuclear fusion devices. A digital holography diagnostic for 3D surface erosion measurement has been developed at Oak Ridge National Laboratory with the goal of deployment on a plasma device. A proof-of-concept in situ demonstration is planned which would involve measurement of plasma erosion on targets exposed to an electrothermal arc source. This work presents the results of an ex situ characterization of the capability and limitations of holographic imaging of targets exposed to the arc source. Targets were designed to provide a fiducial for comparison of deformed and unaffected areas. The results indicated that the average net erosion was ∼150 nm/plasma exposure, which is expected to be within the diagnostic's measurement capacity. Surface roughness averages determined by holographic image analysis showed good agreement with measurements taken with a profilometer. The limit of the holography diagnostic's x-y spatial resolution was characterized by comparison with scanning electron microscope imaging.

Measurements of dynamic surface changes by digital holography for in situ plasma erosion applications

There are currently few viable diagnostic techniques for in situ measurement of plasma facing component erosion. Digital holography is intended to fill this gap. Progress on the development of single and dual CO₂ laser digital holography diagnostics for in situ plasma facing component erosion is discussed. The dual laser mode's synthetic wavelength allows the measurable range to be expanded by a factor of ∼400 compared to single laser digital holography. This allows the diagnostic to measure surface height changes of up to 4.5 μm in single laser mode and up to 2 mm in dual laser mode. Results include ex situ measurements of plasma eroded targets and also dynamic measurements of nm and μm scale motion of a target mounted on a precision translation stage. Dynamic measurements have successfully been made with the system operating in both single and dual laser modes, from ∼50 nm to ∼4 μm in single laser mode and up to ∼400 μm in dual laser mode (limited only by the stage speed and camera acquisition duration). These results demonstrate the feasibility of using digital holography to characterize plasma facing component erosion dynamically, i.e., during plasma exposure. Results of proof-of-principle in situ digital holographic measurements of targets exposed to an electrothermal arc plasma source are presented.

Peeking into the Black Box of Coregistration in Clinical fMRI: Which Registration Methods Are Used and How Well Do They Perform?

BACKGROUND AND PURPOSE

Interpretation of fMRI depends on accurate functional-to-structural alignment. This study explores registration methods used by FDA-approved software for clinical fMRI and aims to answer the following question: What is the degree of misalignment when registration is not performed, and how well do current registration methods perform?

MATERIALS AND METHODS

This retrospective study of presurgical fMRI for brain tumors compares nonregistered images and 5 registration cost functions: Hellinger, mutual information, normalized mutual information, correlation ratio, and local Pearson correlation. To adjudicate the accuracy of coregistration, we edge-enhanced echo-planar maps and rated them for alignment with structural anatomy. Lesion-to-activation distances were measured to evaluate the effects of different cost functions.

RESULTS

Transformation parameters were congruent among Hellinger, mutual information, normalized mutual information, and the correlation ratio but divergent from the local Pearson correlation. Edge-enhanced images validated the local Pearson correlation as the most accurate. Hellinger worsened misalignment in 59% of cases, primarily exaggerating the inferior translation; no cases were worsened by the local Pearson correlation. Three hundred twenty lesion-to-activation distances from 25 patients were analyzed among nonregistered images, Hellinger, and the local Pearson correlation. ANOVA analysis revealed significant differences in the coronal (P < .001) and sagittal (P = .04) planes. If registration is not performed, 8% of cases may have a >3-mm discrepancy and up to a 5.6-mm lesion-to-activation distance difference. If a poor registration method is used, 23% of cases may have a >3-mm discrepancy and up to a 6.9-mm difference.

CONCLUSIONS

The local Pearson correlation is a special-purpose cost function specifically designed for T2*-T1 coregistration and should be more widely incorporated into software tools as a better method for coregistration in clinical fMRI.

Dual laser holography for in situ measurement of plasma facing component erosion (invited)

A digital holography (DH) surface erosion/deposition diagnostic is being developed for 3D imaging of plasma facing component surfaces in situ and in real time. Digital holography is a technique that utilizes lasers reflected from a material surface to form an interferogram, which carries information about the topology of the surface when reconstructed. As described in this paper, dual CO₂ lasers at 9.271 and 9.250 μm wavelengths illuminate the interrogated surface (at a distance of ∼1 m) in a region of ∼1 cm × 1 cm. The surface feature resolution is ∼0.1 mm in the plane of the surface, and the depth resolution ranges from ∼0.0001 to ∼2 mm perpendicular to the surface. The depth resolution lower limit is set by single-laser and detector optical limitations, while the upper limit is determined by 2π phase ambiguity of the dual-laser synthetic wavelength. Measurements have been made "on the bench" to characterize the single-laser and dual-laser DH configurations utilizing standard resolution targets and material targets that were previously exposed to high flux plasmas in either the Prototype Material Plasma Exposure eXperiment (Proto-MPEX) or the electro-thermal (ET) arc source. Typical DH measurements were made with 0.03 ms integration with an IR camera that can be framed at rates approaching 1.5 kHz. The DH diagnostic system is progressing toward in situ measurements of plasma erosion/deposition either on Proto-MPEX or the ET arc source.

Triceps on, alignment off? A comparison of total elbow arthroplasty component positioning with a triceps-on and a triceps-off approach

Introduction This retrospective review investigates whether the triceps-on approach obtains alignment of total elbow arthroplasty implants equivalent to a triceps-off approach. Methods The last 30 consecutive total elbow arthroplasties performed by the senior author were reviewed to identify the approach used and pathology treated. Initially, a triceps split and reflection approach was used, then a triceps-preserving approach. Two blinded reviewers measured the component alignment in standardised radiographs. Pearson's correlation coefficient was calculated to investigate inter/intra-observer and error. The two groups were compared using an unpaired Student t-test. Results There were 13 elbows in the triceps-off group and 17 in the triceps-on group. Pearson's coefficient was 0.75 for interobserver error, 0.89 for intra-observer error. There was no statistical difference between the achieved alignment. All ulna components were flexed with a mean angle deviation of 4.5 degrees in the triceps-off group and 5.7 degrees in the triceps on. Two (15%) ulna components in the triceps-off group were placed in over 5 degrees of flexion, compared with seven (44%) in the triceps-on group. Conclusion These results demonstrate no statistical difference in the achieved alignment between the two groups. Surgeons should beware of the tendency to place the ulna component in a flexed position, especially in the triceps-on approach.

Comparative learning curves for early complications in anatomical and reverse shoulder arthroplasty

Introduction There has been a significant increase in the implantation of reverse shoulder replacements over anatomical shoulder replacements in the past five years. Few comparative data exist comparing early complication rates and learning curves. This study aimed to evaluate the early complication rates and learning curves of a single surgeon series of anatomical and reverse shoulder replacements over the first five years of independent practice. Materials and methods The first 100 anatomical and 100 reverse shoulder replacements performed between July 2011 and July 2016 were reviewed to identify early complications. Cumulative sum plots were used to analyse the learning-curve effect. Results Early complications were noted in 4 anatomical and 17 reverse shoulder replacements. One of the anatomical and ten of the reverse shoulder replacements required a return to theatre within three months. The early complication rates were observed to be significantly higher in the reverse shoulder replacement group compared with the anatomical shoulder replacement group (odds ratio 4.9; 95% confidence interval 1.6-15.2, P 1/4 0.057). An inflection point on the anatomical shoulder replacement cumulative sum plot suggestive of a trend to consistent performance was reached at 16 cases. No inflection point was observed on the reverse shoulder replacement cohort. Conclusions We observed a significantly higher early complication rate within the reverse shoulder replacement cohort, with a tenfold increase in early reoperations. In comparison to the trend seen after 16 cases for anatomical shoulder replacement, no trend was seen in the reverse shoulder replacement cohort. This either reflects the higher complication rate seen in reverse shoulder replacement or that the learning curve extends beyond 100 cases, highlighting the need for extended performance monitoring.

The colonisation of the glenohumeral joint by Propionibacterium acnes is not associated with frozen shoulder but is more likely to occur after an injection into the joint

AIMS

Our aim was to investigate the prevalence of Propionibacterium (P.) acnes in the subcutaneous fat and capsule of patients undergoing shoulder surgery for frozen shoulder or instability.

PATIENTS AND METHODS

A total of 46 patients undergoing either an arthroscopic capsular release or stabilisation had biopsies taken from the subcutaneous fat and capsule of the shoulder at the time of surgery. These samples were sent for culture in enrichment, and also for Nucleic Acid Amplification testing. The prevalence of P. acnes and other microbes was recorded. Fisher's exact test of binary variables was used to calculate the association with significance set at p < 0.05. Assessment of influence of independent variables including a pre-operative glenohumeral injection, fat colonisation and gender, was undertaken using binary linear regression.

RESULTS

A total of 25 patients (53%) had P. acnes in one or more tissue samples and 35 (74%) had other bacterial species. The same microbe was found in the subcutaneous fat and the capsule in 13 patients (28%). There was no statistically significant association between the surgical pathology and capsular colonisation with P. acnes (p = 0.18) or mixed identified bacterial species (p = 0.77). Male gender was significantly associated with an increased capsular colonisation of P. acnes (odds ratio (OR) 12.38, 95% confidence interval (CI) 1.43 to 106.77, p = 0.02). A pre-operative glenohumeral injection was significantly associated with capsular P. acnes colonisation (OR 5.63, 95% CI 1.07 to 29.61, p = 0.04. Positive fat colonisation with P. acnes was significantly associated with capsular P. acnes (OR 363, 95% CI 20.90 to 6304.19, p < 0.01). Regression models pseudo R² found fat colonisation with P. acnes to explain 70% of the variance of the model. Patients who had a pre-operative glenohumeral injection who were found intra-operatively to have fat colonisation with P. acnes had a statistically significant association with colonisation of their capsule with P. acnes (OR 165, 95% CI 13.51 to 2015.24, p < 0.01).

CONCLUSION

These results show a statistically significant association between subcutaneous skin P. acnes culture and P. acnes capsular culture, especially when the patient has undergone a previous injection. The results refute the hypothesis that P. acnes causes frozen shoulder. Cite this article: Bone Joint J 2017;99-B:1067-72.

Anatomy of the terminal branch of the posterior circumflex humeral artery: relevance to the deltopectoral approach to the shoulder

AIMS

Despite the expansion of arthroscopic surgery of the shoulder, the open deltopectoral approach is increasingly used for the fixation of fractures and arthroplasty of the shoulder. The anatomy of the terminal branches of the posterior circumflex humeral artery (PCHA) has not been described before. We undertook an investigation to correct this omission.

PATIENTS AND METHODS

The vascular anatomy encountered during 100 consecutive elective deltopectoral approaches was recorded, and the common variants of the terminal branches of the PCHA are described.

RESULTS

In total, 92 patients (92%) had a terminal branch that crossed the space between the deltoid and the proximal humerus and which was therefore vulnerable to tearing or avulsion during the insertion of the blade of a retractor during the deltopectoral approach to the shoulder. In 75 patients (75%) there was a single vessel, in 16 (16%) a double vessel and in one a triple vessel.

CONCLUSION

The relationship of these vessels to the landmark of the tendon of the insertion of pectoralis major into the proximal humerus is described. Damage to these previously undocumented branches can cause persistent bleeding leading to prolonged surgery and post-operative haematoma and infection, as well as poor visualisation during the procedure. Cite this article: Bone Joint J 2016;98-B:1395-8.

Correction of ischaemic brain acidosis with SQ29,548/1-benzylimidazole

Thromboxane A2 (TXA2) is a proaggregatory vasoconstrictor that is synthesized and released during reperfusion of ischaemic brain. We administered a TXA2 receptor antagonist, SQ29,548, and a thromboxane A synthase inhibitor, 1-benzylimidazole (1-BI), to rats subjected to 30 min of reversible forebrain ischaemia. Cerebral thromboxane B2 (TXB2), the stable metabolite of TXA2, measured after 60 min of reperfusion was 0.37 +/- 0.08 ng/mg brain protein in animals treated with SQ29,548/1-BI compared with 1.20 +/- 0.16 in ischaemic controls (p < 0.05). Cerebral pH determined by 31P magnetic resonance spectroscopy was higher in treated animals, 7.06 +/- 0.04, than in ischaemic controls, 6.5 +/- 0.01, after 20 min of reperfusion (p < or = 0.01). The significant elevation of cerebral pH in treated animals persisted at 30 (7.17 +/- 0.05 vs. 6.5 +/- 0.01; p < or = 0.01), 35 (7.17 +/- 0.05 vs. 6.44 +/- 0.04; p < or = 0.01), and 40 min of reperfusion (7.06 +/- 0.06 vs. 6.37 +/- 0.01; p < or = 0.05). We conclude that SQ29,548/1-BI reduces thromboxane levels and promotes resolution of tissue acidosis in ischaemic brain. The combination of a TXA2 receptor antagonist with a thromboxane A synthase inhibitor deserves further study as a potential treatment for acute cerebral infarction.

Arthroscopic capsular release for idiopathic frozen shoulder with intra-articular injection and a controlled manipulation

INTRODUCTION

The aim of this prospective study was to assess the immediate and long-term effectiveness of arthroscopic capsular release in a large cohort of patients with a precise and isolated diagnosis of stage II idiopathic frozen shoulder.

METHODS

All patients underwent a preoperative evaluation. Patients with secondary frozen shoulder and those with concurrent pathology at arthroscopy were excluded. This left 136 patients with a stage II arthroscopically confirmed idiopathic frozen shoulder. At each postoperative attendance, a record was made of pain, function and range of motion. At 12 months, the Oxford shoulder score was calculated, and pain and range of motion were assessed.

RESULTS

Fifty per cent achieved good pain relief within a week and eighty per cent within six weeks of arthroscopic capsular release. The mean preoperative visual analogue scale pain score was 6.6 and the mean postoperative score was 1.0. The mean time to achieving good pain relief was 16 days following surgery. No patient could sleep through the night prior to surgery while 90% reported having a complete night's sleep at a mean of 12 days after surgery. The mean postoperative Oxford shoulder score was 38/48 and the mean improvement was 19.2.

CONCLUSIONS

This large series demonstrates that arthroscopic capsular release is a safe procedure, with rapid improvement in pain and a marked improvement in range of motion.

The frequency of and associations with hospitalization secondary to lupus flares from the 1000 Faces of Lupus Canadian cohort

Objectives

Hospitalization is a major factor in health care costs and a surrogate for worse outcomes in chronic disease. The aim of this study was to determine the frequency of hospitalization secondary to lupus flare, the causes of hospitalization, and to determine risk factors for hospitalization in patients with systemic lupus erythematosus (SLE).

Methods

Data were collected as part of the 1000 Canadian Faces of Lupus, a prospective cohort study, where annual major lupus flares including hospitalizations were recorded over a 3-year period.

Results

Of 665 patients with available hospitalization histories, 68 reported hospitalization related to a SLE flare over 3 years of follow-up. The average annual hospitalization rate was 7.6% (range 6.6–8.9%). The most common reasons for hospitalization were: hematologic (22.1%), serositis (20.6%), musculoskeletal (MSK) (16.2%), and renal (14.7%). Univariate risk factors for lupus hospitalization included (OR [95% CI]; p < 0.05): juvenile-onset lupus (2.2 [1.1–4.7]), number of ACR SLE criteria (1.4 [1.1–1.7], baseline body mass index (BMI) (1.1 [1.0–1.1]), psychosis (3.4 [1.2–9.9]), aboriginal race (3.2 [1.5–6.7]), anti-Smith (2.6 [1.2–5.4]), erythrocyte sedimentation rate >25 mm/hr (1.9 [1.1–3.4]), proteinuria >0.5 g/d (4.2 [1.9–9.3], and SLAM-2 score (1.1 [1.0–1.2]). After multivariate regression only BMI, number of ACR criteria, and psychosis were associated with hospitalization for lupus flare.

Conclusions

The mean annual rate of hospitalization attributed to lupus was lower than expected. Hematologic, serositis, MSK and renal were the most common reasons. In a regression model elevated BMI, more ACR criteria and psychosis were associated with hospitalization.

Genotype-phenotype studies of VCP-associated inclusion body myopathy with Paget disease of bone and/or frontotemporal dementia

Valosin containing protein (VCP) disease associated with inclusion body myopathy, Paget disease of the bone and frontotemporal dementia is a progressive autosomal dominant disorder caused by mutations in Valosin containing protein gene. To establish genotype-phenotype correlations we analyzed clinical and biochemical markers from a database of 190 members in 27 families harboring 10 missense mutations. Individuals were grouped into three categories: symptomatic, presymptomatic carriers and noncarriers. The symptomatic families were further divided into ten groups based on their VCP mutations. There was marked intra and inter-familial variation; and significant genotype-phenotype correlations were difficult to establish because of small numbers. Nevertheless when comparing the two most common mutations, R155C mutation was found to be more severe, with an earlier onset of myopathy and Paget (p = 0.03). Survival analysis of all subjects revealed an average life span after diagnosis of myopathy and Paget of 18 and 19 years respectively, and after dementia only 6 years. R155C had a reduced survival compared to the R155H mutation (p = 0.03).We identified amyotrophic lateral sclerosis (ALS) was diagnosed in 13 individuals (8.9%) and Parkinson's disease in five individuals (3%); however, there was no genotypic correlation. This study represents the largest dataset of patients with VCP disease and expands our understanding of the natural history and provides genotype-phenotype correlations in this unique disease.

Indications for reverse shoulder replacement: a systematic review

The outcome of an anatomical shoulder replacement depends on an intact rotator cuff. In 1981 Grammont designed a novel large-head reverse shoulder replacement for patients with cuff deficiency. Such has been the success of this replacement that it has led to a rapid expansion of the indications. We performed a systematic review of the literature to evaluate the functional outcome of each indication for the reverse shoulder replacement. Secondary outcome measures of range of movement, pain scores and complication rates are also presented.

Direct fed microbial supplementation repartitions host energy to the immune system

Direct fed microbials and probiotics are used to promote health in livestock and poultry; however, their mechanism of action is still poorly understood. We previously reported that direct fed microbial supplementation in young broilers reduced ileal respiration without changing whole-body energy expenditure. The current studies were conducted to further investigate the effects of a direct fed microbial on energy metabolism in different tissues of broilers. One hundred ninety-two 1-d-old broiler chicks (16 chicks/pen) were randomly assigned to 2 dietary groups: standard control starter diet (CSD) and CSD plus direct fed microbial (DFMD; 0.3%) with 6 pens/treatment. Body weight, feed consumption, whole-body energy expenditure, organ mass, tissue respiration rates, and peripheral blood mononuclear cell (PBMC) ATP concentrations were measured to estimate changes in energy metabolism. No differences in whole body energy expenditure or BW gain were observed; however, decreased ileal O(2) respiration (P < 0.05) was measured in DFMD fed broilers. In contrast, the respiration rate of the thymus in those broilers was increased (P < 0.05). The PBMC from DFMD fed broilers had increased ATP concentrations and exhibited increased ATP turnover (P < 0.01). To determine if the increased energy consumption by PBMC corresponded with an altered immune response, broilers were immunized with sheep red blood cells (SRBC) and assayed for differences in their humoral response. The DFMD-fed broilers had a faster rate of antigen specific IgG production (P < 0.05) and an increase in total IgA (P < 0.05). Collectively, these data indicate that supplementation with the direct fed microbial used in this study resulted in energy re-partitioning to the immune system and an increase in antibody production independent of changes in whole body metabolism or growth performance.

Another fractured neck of femur: do we need a lateral X-ray?

OBJECTIVE

This study aimed to define the role of the lateral X-ray in the assessment and treatment planning of proximal femoral fractures. Occult fractures were not included.

METHODS

Radiographs from 359 consecutive patients with proximal femoral fractures admitted to our emergency department over a 12 month period were divided into anteroposterior (AP) views and lateral views. Three blinded reviewers independently assessed the radiographs, first AP views alone then AP plus lateral views, noting the fracture classification for each radiograph. These assessments were then compared with the intra-operative diagnosis, which was used as the gold standard. A 2 × 2 contingency square table was created and Pearson's χ(2) test was used for statistical analysis.

RESULTS

The rate of correct classification by the reviewers was improved by the assessment of the lateral X-ray in addition to the AP view for intracapsular fractures (p<0.013) but not for extracapsular fractures (p=0.27). However, the only advantage obtained by assessing the lateral view in intracapsular fractures was the detection of displacement where the fracture appeared undisplaced on the initial AP view.

CONCLUSION

This study provides statistical evidence that one view is adequate and safe for the majority of hip fractures. The lateral radiograph should not be performed routinely in order to make considerable savings in money and time and to avoid unnecessary patient discomfort.

Relative preservation of MMSE scores in autopsy-proven dementia with Lewy bodies

BACKGROUND

Recent studies raised questions about the severity of cognitive impairment associated with dementia with Lewy bodies (DLB). However, there have been few analyses of large, multicenter data registries for clinical-pathologic correlation.

METHODS

We evaluated data from the National Alzheimer's Coordinating Center registry (n = 5,813 cases meeting initial inclusion criteria) and the University of Kentucky Alzheimer's Disease Center autopsy series (n = 527) to compare quantitatively the severity of cognitive impairment associated with DLB pathology vs Alzheimer disease (AD) and AD+DLB pathologies.

RESULTS

Mini-Mental State Examination (MMSE) scores showed that persons with pure DLB had cognitive impairment of relatively moderate severity (final MMSE score 15.6 +/- 8.7) compared to patients with pure AD and AD+DLB (final MMSE score 10.7 +/- 8.6 and 10.6 +/- 8.6). Persons with pure DLB pathology from both data sets had more years of formal education and were more likely to be male. Differences in final MMSE scores were significant (p < 0.01) between pure DLB and both AD+DLB and pure AD even after correction for education level, gender, and MMSE-death interval. Even in cases with extensive neocortical LBs, the degree of cognitive impairment was most strongly related to the amount of concomitant AD-type neurofibrillary pathology.

CONCLUSIONS

Dementia with Lewy bodies can constitute a debilitating disease with associated psychiatric, motoric, and autonomic dysfunction. However, neocortical Lewy bodies are not a substrate for severe global cognitive impairment as assessed by the Mini-Mental State Examination. Instead, neocortical Lewy bodies appear to constitute or reflect an additive disease process, requiring Alzheimer disease or other concomitant brain diseases to induce severe global cognitive deterioration.

Prodromal clinical manifestations of neuropathologically confirmed Lewy body disease

The mild cognitive impairment (MCI) stage of dementia with Lewy bodies (MCI-DLB) has not yet been defined, but is likely to differ in the MCI stage of Alzheimer's disease (MCI-AD). To determine whether clinical features distinguish MCI-DLB and MCI-AD, 9 cases of neuropathologically confirmed MCI-DLB and 12 cases of MCI-AD were compared. No significant differences were found between MCI-DLB and MCI-AD cases in age at death, gender, ApoE status, education, time followed while clinically normal, or duration of MCI. MCI-DLB and MCI-AD cases differed clinically in the expression of Parkinsonism (P=0.012), provoked hallucinations or delirium (P=0.042), or the presence of any of these noncognitive symptoms of DLB (P<0.0001). Letter fluency (P=0.007) was significantly lower and Wechsler Logical Memory I (P=0.019) was significantly higher in MCI-DLB compared to MCI-AD cases. These data demonstrate the feasibility of differentiating underlying pathologic processes responsible for cognitive decline in the preclinical disease state and suggest that further refinement in diagnostic criteria may allow more accurate early detection of prodromal DLB and AD.

Improved predictive model for pre-symptomatic mild cognitive impairment and Alzheimer's disease

OBJECTIVE

Delineation of gray matter (GM) structures on brain MRI scans is termed segmentation. Accuracy of segmentation is a key factor in the valid comparison of GM density and volume between individuals and groups. Previously, it was demonstrated that a group of normal subjects who later developed mild cognitive impairment (MCI) had decreased GM volume in the medial temporal lobe compared to other normal subjects who remained normal an average 5.4 years after the scan. The objective of this study was to show whether accuracy of this predictive model was increased using an advanced segmentation technique.

METHODS

Structural MRI was performed on 74 longitudinally examined normal aged subjects. All subjects were cognitively normal at the time of their scan, but 18 later developed MCI, and six of these 18 went on from MCI to an AD diagnosis. We independently delineated GM using both a standard segmentation technique and a local Gaussian active contour (LGAC) technique. We compared the contribution of extracted volumes from each technique to a model predicting subjects who will eventually develop MCI.

RESULTS

Accuracy of the standard technique to distinguish pre-MCI from normal using imaging alone was 79% (sensitivity 78% and specificity 73%). Using LGAC, accuracy rose to 84% (sensitivity 78% and specificity 84%).

DISCUSSION

Structural brain changes precede MCI in longitudinally followed normal subjects. The LGAC technique improves the accuracy of a predictive model incorporating these structural changes by improving GM segmentation and the specificity of the model.

Removal of embedded central venous catheters

BACKGROUND/PURPOSE

Long-term central venous access devices (CVAD) play an integral role in the management of children who require nutritional support, chemotherapy, blood drawing, and transfusion of blood products. Infrequently, the CVAD may be difficult or impossible to remove with traction.

PATIENT POPULATION

Four patients, with ages ranging from 6 to 13 years, had 4 CVAD in place for 431, 730, 2232, and 3285 days which could not be removed by manual traction and local exploration.

RESULTS

With the use of technology developed for removal of embedded transvenous pacemaker catheters, each CVAD was successfully dislodged using a lead locking device (n = 3) or a lead locking device and an excimer laser (n = 1). There were no complications of the procedure in our series.

CONCLUSIONS

There is no consensus on optimal management of embedded CVADs. In this small series, devices used routinely to remove embedded transvenous pacemaker wires were used to extract 4 embedded CVADs without complication; however, use of this technology in pediatric surgical patients is controversial because a small percentage of adult cases have resulted in tamponade or hemothorax, potentially resulting in death. Selection of patients and use of the technology in the appropriate setting are important considerations in weighing the risks vs the benefits of extracting such catheters or leaving them in place.

Collagenous microstructure of the glenoid labrum and biceps anchor

The glenoid labrum is a significant passive stabilizer of the shoulder joint. However, its microstructural form remains largely unappreciated, particularly in the context of its variety of functions. The focus of labral microscopy has often been histology and, as such, there is very little appreciation of collagen composition and arrangement of the labrum, and hence the micromechanics of the structure. On transmission electron microscopy, significant differences in diameter, area and perimeter were noted in the two gross histological groups of collagen fibril visualized; this suggests a heterogeneous collagenous composition with potentially distinct mechanical function. Scanning electron microscopy demonstrated three distinct zones of interest: a superficial mesh, a dense circumferential braided core potentially able to accommodate hoop stresses, and a loosely packed peri-core zone. Confocal microscopy revealed an articular surface fine fibrillar mesh potentially able to reduce surface friction, bundles of circumferential encapsulated fibres in the bulk of the tissue, and bone anchoring fibres at the osseous interface. Varying microstructure throughout the depth of the labrum suggests a role in accommodating different types of loading. An understanding of the labral microstructure can lead to development of hypotheses based upon an appreciation of this component of material property. This may aid an educated approach to surgical timing and repair.

Tensile properties of the human glenoid labrum

Human fresh-frozen cadaveric glenoid labrae from 16 donors were harvested and ten of these had no gross degeneration. These ten were divided into eight equal circumferential sections. Each section was cut to produce test-samples from the core layer with a cross-section of 1 x 1 mm. Tensile testing was performed within a controlled environment unit at 37 +/- 1 degrees C and 100% relative humidity. Each test-sample was precycled to a quasi-static state to alleviate the effects of deep-freezing, prior to final testing. The tangent modulus was calculated for each test-sample before and after a 5-min period of stress relaxation and at yield. The mean elastic modulus and yield stress of the glenoid labrum were 22.8 +/- 11.4 and 2.5 +/- 2.1 MPa, respectively. The anterosuperior portion had a lower elastic modulus and lower yield stress than the inferior portion (both P < 0.02). The pre-stress relaxation tangent modulus was significantly lower than the post-stress relaxation tangent modulus for all portions of the labrum. The glenoid labrum has similar tensile material properties to articular cartilage. Its elastic modulus varies around its circumference. This suggests that the labrum may encounter different forces at different positions.

Brain structural alterations before mild cognitive impairment

OBJECTIVE

To determine whether alterations of brain structure in normal aged individuals precede the development of mild cognitive impairment (MCI) or Alzheimer disease (AD).

BACKGROUND

Persons with MCI and AD demonstrate cortical volume losses vs asymptomatic aged individuals, particularly in the hippocampus, amygdala, and entorhinal cortex. It is unknown whether these losses or other volumetric changes are present, and to what degree, in cognitively normal individuals before the clinical diagnosis of MCI.

METHODS

Structural MRI was performed on a cross-section of 136 longitudinally examined normal aged subjects. All subjects were cognitively normal at the time of their scan, but 23 later developed MCI, and 9 of these 23 went on to an AD diagnosis. Extracted volumes from voxel-based morphometric analysis were combined with clinical data to compare the 23 subjects who eventually developed MCI to 113 subjects who remained cognitively normal over an average follow-up of 5.4 years.

RESULTS

Initially normal subjects who eventually developed MCI demonstrated decreased gray matter volumes in the anteromedial temporal lobes bilaterally and left angular gyrus while still cognitively normal.

CONCLUSION

Structural brain changes in anatomic areas involved in higher cognitive processes precede clinical signs and symptoms in longitudinally followed normal subjects destined to develop mild cognitive impairment.

Radiofrequency energy delivery to the lower esophageal sphincter (Stretta procedure) in patients with recurrent reflux after antireflux surgery: can surgery be avoided?

BACKGROUND

Recurrent reflux following antireflux surgery (ARS) can be difficult to manage, especially in patients who also fail medical management. In these patients, redo ARS remains the only treatment option. Endoscopic radiofrequency energy delivery to the lower esophageal sphincter (the Stretta procedure; Stretta, Curon, Sunnyvale, CA) has been shown to significantly decreased symptom scores and improve quality of life in patients with gastroesophageal reflux disease (GERD). The aim of this study was to evaluate the use of the Stretta procedure in treating patients with recurrent reflux after fundoplication.

METHODS

Between March 2002 and December 2003, eight patients with recurrent reflux following ARS underwent the Stretta procedure. All patients were asked to complete an institutional symptom survey pre-Stretta and at 1, 6, and 12 months after the procedure. Patients rated 7 reflux-related symptoms (heartburn, dysphagia, regurgitation, cough, voice changes/hoarseness, asthma, chest pain) on a 0 (none) to 3 (severe) scale. Data were analyzed using a Wilcoxon matched pairs signed rank test where appropriate.

RESULTS

Complete data were obtained for seven of the eight patients, with a median follow-up of 253 days (range, 67-378 days). One patient was lost to follow-up and not included in our analysis. Symptom scores decreased significantly, with six patients noting both improved typical and atypical symptoms. Overall, six patients (85%) were satisfied with their results.

CONCLUSIONS

Based on this small series, the Stretta procedure significantly reduces subjective symptoms of GERD. The Stretta procedure may serve an important role as an additional management strategy to help manage recurrent GERD after ARS.

The effect of escalating feedback on the acquisition of psychomotor skills for laparoscopy

BACKGROUND

In the acquisition of new skills that are difficult to master, such as those required for laparoscopy, feedback is a crucial component of the learning experience. Optimally, feedback should accurately reflect the task performance to be improved and be proximal to the training experience. In surgery, however, feedback typically is in vivo. The development of virtual reality training systems currently offers new training options. This study investigated the effect of feedback type and quality on laparoscopic skills acquisition.

METHODS

For this study, 32 laparoscopic novices were prospectively randomized into four training conditions, with 8 in each group. Group 1 (control) had no feedback. Group 2 (buzzer) had audio feedback when the edges were touched. Group 3 (voiced error) had an examiner voicing the word "error" each time the walls were touched. Group 4 (both) received both the audio buzzer and "error" voiced by the examiner All the subjects performed a maze-tracking task with a laparoscopic stylus inserted through a 5-mm port to simulate the fulcrum effect in minimally invasive surgery (MIS). A computer connected to the stylus scored an error each time the edge of the maze was touched, and the subjects were made aware of the error in the aforementioned manner. Ten 2-min trials were performed by the subjects while viewing a monitor. At the conclusion of training, all the subjects completed a 2-min trial of a simple laparoscopic cutting task, with the number of correct and incorrect incisions recorded.

RESULTS

Group 4 (both) made significantly more correct incisions than the other three groups (F = 12.13; df = 3, 28; p < 0.001), and also made significantly fewer errors or incorrect incisions (F = 14.4; p < 0.0001). Group 4 also made three times more correct incisions and 7.4 times fewer incorrect incisions than group 1 (control).

CONCLUSIONS

The type and quality of feedback during psychomotor skill acquisition for MIS have a large effect on the strength of skills generalization to a simple MIS task and should be given serious consideration in curriculum design for surgical training using simulation tasks.

Endoscopic ablation of intestinal metaplasia containing high-grade dysplasia in esophagectomy patients using a balloon-based ablation system

BACKGROUND

This study aimed to determine the optimal treatment parameters for the ablation of intestinal metaplasia (IM) containing high-grade dysplasia (HGD) using a balloon-based ablation system for patients undergoing esophagectomy.

METHODS

Immediately before esophagectomy, patients underwent ablation of circumferential segments of the esophagus containing IM-HGD using the HALO360 system. The treatment settings were randomized to 10, 12, or 14 J/cm2 for two, three, or four applications. After esophagectomy, multiple sections from ablation zones were microscopically evaluated. Histologic end points included maximum ablation depth (histologic layer) and complete ablation of all IM-HGD (yes/no).

RESULTS

Eight men with a mean age of 57 years (range, 45-71 years) were treated, and 10 treatment zones were created. There were no device-related adverse events. At resection, there was no evidence of a transmural thermal effect. Grossly, ablation zones were clearly demarcated sections of ablated epithelium. The maximum ablation depth was the lamina propria or muscularis mucosae. The highest energy (14 J/cm2, 4 applications) incurred edema in the superficial submucosa, but no submucosa ablation. Complete ablation of IM and HGD occurred in 9 of 10 ablation zones (90%), defined as complete removal of the epithelium with only small foci of "ghost cells" representing nonviable, ablated IM-HGD and demonstrating loss of nuclei and cytoarchitectural derangement. One focal area of viable IM-HGD remained at the margin of one ablation zone (12 J/cm2, 2 applications) because of incomplete overlap.

CONCLUSION

Complete ablation of IM-HGD without ablation of submucosa is possible using the HALO360 system. Ablation depth is dose related and limited to the muscularis mucosae. In one patient, small residual foci of IM-HGD at the edge of the ablation zone were attributable to incomplete overlap, which can be avoided. This study, together with nonesophagectomy IM-HGD trials currently underway, will identify the optimal treatment parameters for IM-HGD patients who would otherwise undergo esophagectomy or photodynamic therapy.

Attempted establishment of proficiency levels for laparoscopic performance on a national scale using simulation: the results from the 2004 SAGES Minimally Invasive Surgical Trainer—Virtual Reality (MIST-VR) learning center study

BACKGROUND

The Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) has been well validated as a training device for laparoscopic skills. It has been demonstrated that training to a level of proficiency on the simulator significantly improves operating room performance of laparoscopic cholecystectomy. The purpose of this project was to obtain a national standard of proficiency using the MIST-VR based on the performance of experienced laparoscopic surgeons.

METHODS

Surgeons attending the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) 2004 Annual Scientific Meeting who had performed more than 100 laparoscopic procedures volunteered to participate. All the subjects completed a demographic questionnaire assessing laparoscopic and MIST-VR experience in the learning center of the SAGES 2004 meeting. Each subject performed two consecutive trials of the MIST-VR Core Skills 1 program at the medium setting. Each trial involved six basic tasks of increasing difficulty: acquire place (AP), transfer place (TP), traversal (TV), withdrawal insert (WI), diathermy task (DT), and manipulate diathermy (MD). Trial 1 was considered a "warm-up," and trial 2 functioned as the test trial proper. Subject performance was scored for time, errors, and economy of instrument movement for each task, and a cumulative total score was calculated.

RESULTS

Trial 2 data are expressed as mean time in seconds in Table 2.

CONCLUSION

Proficiency levels for laparoscopic skills have now been established on a national scale by experienced laparoscopic surgeons using the MIST-VR simulator. Residency programs, training centers, and practicing surgeons can now use these data as guidelines for performance criterion during MIST-VR skills training.

Updated cardiac safety results of dose-dense (DD) doxorubicin and cyclophosphamide (AC) followed by paclitaxel (T) with trastuzumab (H) in HER2/neu overexpressed/amplified breast cancer (BCA)

582

Background: DD q 2 weekly (w) AC → T is superior to conventionally scheduled (cs) AC → T and safe w/long follow-up (Hudis et al, SABCS 2005). With q 3 wk AC, adjuvant (adj) H is safe and effective (Romond et al and Perez et al, NEJM 2005). We therefore tested DD q 2 w AC → T + H × 1 year (y) as adj treatment (Rx) of patients (pts) with HER2/neu (+) BCA to determine cardiac safety. Based on the reported cardiac event (CE) rate of ≤ 4% in the randomized trials using cs chemotherapy (CRx) + H, we evaluated DD q 2 w AC → T + H with a 1° endpoint of cardiac safety defined as discontinuation (DC) of H due to 1) cardiac death or 2) congestive heart failure (CHF). The 2° endpoint is time to recurrence and overall survival. Methods: Pts with HER2/Neu IHC 3+ or FISH-amplified BCA were enrolled, regardless of tumor size or nodal status. Rx consisted of AC at 60/600 mg/m2 × 4 → T at 175 mg/m2 × 4 q 2 w w/pegfilgrastim 6 mg on d 2 + H × 1 y. Multi-gated radionuclide angiography scan (MUGA) is obtained at baseline and at months (mo) 2 (after AC × 4), 6 (after T × 4), 9, and 18. Pts w/baseline LVEF of ≥ 55% and w/o cardiac illnesses are eligible. Pts w/significant (sig) asymptomatic (asx) LVEF ↓ after DD AC based on mo 2 MUGA did not receive H, and pts w/sig asx LVEF ↓ during H had it DC’d. If the CE rate is > 4%, Rx is deemed not feasible. Results: From January 4, 2005 to November 1, 2005, 70 pts were enrolled. Median (med) age is 49 years (range, 27–72). Forty one of 70 pts (60%) had node (+) BC and 27/70 pts (40%) had (-) nodes. Med baseline LVEF is 68% (range, 55%-81%). As of January 9, 2005, all pts had mo 2 MUGA after DD AC and there is no sig LVEF ↓ and the med LVEF is 67% (range, 58%-79%). To date 39 pts had mo 6 MUGA w/med LVEF of 66% (range, 56%-75%) and one pt had a sig asx LVEF ↓ from baseline of 74% to 56%; H was DC’d. Twenty-three pts had mo 9 MUGA w/a med LVEF of 64% (range, 57%-69%). One patient had clinical CHF at mo 4 w/EF of 45% and improved sig w/cardiac medications. One had pneumonitis during radiation (RT). One had atrial fibrillation w/pericarditis after completion of RT. Discussion: DD AC → T + H appears to have an acceptable cardiac toxicity profile w/1/70 pts having a CE. Updated cardiac safety data will be presented.

[Table: see text]

Surgeon-initiated screening colonoscopy program based on SAGES and ASCRS recommendations in a general surgery practice

BACKGROUND

This study aimed to determine the utility of a screening colonoscopy program initiated by general surgeons in an academic center.

METHODS

New patients presenting to three general surgeons who met screening colonoscopy indications were asked whether they had undergone colorectal cancer (CRC) screening. The patients who had not undergone CRC screening were offered screening colonoscopies or referred to their gastroenterologists.

RESULTS

In the first 9-month period of the program, 200 patients who met the Society of American Gastrointestinal and Endoscopic Surgeons/American Society of Colon and Rectal Surgeons indications for CRC screening were asked whether they had undergone screenings. Only 46% (n = 92) reported any prior appropriate screenings. Of the patients who elected CRC screening by the surgeons, 55 underwent full colonoscopies (2 concurrently with hemorrhoidectomies), and 2 had flexible sigmoidoscopies. As a result of screening, 10 patients (18%) required treatment: 7 had polypectomies, 2 had partial colectomies, and 1 with an indication for surgery deferred treatment.

CONCLUSIONS

Most of the patients presenting to the general surgeon likely have not had CRC screening, and diligence in making appropriate recommendations should be routine. Colonoscopic findings requiring intervention are not insignificant.

MRI volumetric and intensity analysis of the cerebellum in Parkinson's disease patients infused with glial-derived neurotrophic factor (GDNF)

BACKGROUND

A recent human therapeutic trial using intraputaminal infusion of glial cell-derived neurotrophic factor (GDNF) in Parkinson's disease (PD) was abruptly terminated, partly due to safety concerns raised by the finding of cerebellar lesions in monkeys given high-dose GDNF.

METHODS

Magnetic resonance images from nine PD patients participating in this trial were analyzed to determine whether subtle volumetric or intensity changes could be detected in the cerebellum or elsewhere following GDNF treatment for over 1 year. Subtraction images were compared to a reference standard deviation map constructed by using identically-processed paired scans from 25 normal adults. In a separate voxel-based group morphometric (VBM) analysis of the same patient images, grey matter intensity was compared between pre and post-GDNF infusion scans using a repeated measures ANOVA with family-wise error threshold of P = 0.10. Two expert readers independently reviewed serial FLAIR images from all patients.

RESULTS

(1) There were no significant cerebellar differences in any of the nine individual PD patients (difference image analysis), (2) there were no significant morphometric differences between pre- and post-GDNF scans (VBM), and (3) there were no signal abnormalities in the cerebellum detected on the FLAIR images in PD patients (clinical scan review).

CONCLUSIONS

In concert with lack of evidence of cerebellar dysfunction on clinical examination, we find no imaging evidence of cerebellar injury in human subjects undergoing chronic intracerebral GDNF infusion.

Thin-layer ablation of human esophageal epithelium using a bipolar radiofrequency balloon device

BACKGROUND

The goal of this study was to determine the optimal treatment parameters for the ablation of human esophageal epithelium using a balloon-based bipolar radiofrequency (RF) energy electrode.

METHODS

Immediately prior to esophagectomy, subjects underwent esophagoscopy and ablation of two separate, 3-cm long, circumferential segments of non-tumor-bearing esophageal epithelium using a balloon-based bipolar RF energy electrode (BARRX Medical, Inc., Sunnyvale, CA, USA). Subjects were randomized to one of three energy density groups: 8, 10, or 12 J/cm2. RF energy was applied one time (1x) proximally and two times (2x) distally. Following resection, sections from each ablation zone were evaluated using H&E and diaphorase. Histological endpoints were complete epithelial ablation (yes/no), maximum ablation depth, and residual ablation thickness after tissue slough. Outcomes were compared according to energy density group and 1x vs 2x treatment.

RESULTS

Thirteen male subjects (age, 49-85 years) with esophageal adenocarcinoma underwent the ablation procedure followed by total esophagectomy. Complete epithelial removal occurred in the following zones: 10 J/cm2 (2x) and 12 J/cm2 (1x and 2x). The maximum depth of injury was the muscularis mucosae: 10 and 12 J/cm2 (both 2x). A second treatment (2x) did not significantly increase the depth of injury. Maximum thickness of residual ablation after tissue slough was only 35 microm.

CONCLUSIONS

Complete removal of the esophageal epithelium without injury to the submucosa or muscularis propria is possible using this balloon-based RF electrode at 10 J/cm2 (2x) or 12 J/cm2 (1x or 2x). A second application (2x) does not significantly increase ablation depth. These data have been used to select the appropriate settings for treating intestinal metaplasia in trials currently under way.

Longitudinal functional alterations in asymptomatic women at risk for Alzheimer's disease

PURPOSE

The authors sought to determine whether known alterations of brain function in normal individuals who are at high risk for Alzheimer's disease (AD) worsen or stay the same after a significant interval of time.

METHODS

The authors used functional magnetic resonance imaging (fMRI) to observe cortical activation during confrontation naming in 14 women with high AD risk and 10 with low risk, based on family history and apolipoprotein-E4 allele status. They repeated the identical scan protocol in the same patients after 4 years.

RESULTS

fMRI activation in high-AD-risk participants was found to be further diverged from that of their low-AD-risk counterparts over this period.

CONCLUSION

fMRI may report on the presence and progression of neuropathology in the ventral temporal cortex or in functionally connected regions in presymptomatic AD.

What happens to the rectus abdominus fascia after laparoscopic ventral hernia repair?

BACKGROUND

One criticism of laparoscopic ventral hernia repair (LVH) is that the rectus muscles are not re-approximated to the midline, and the effect of LVH repair on the fascial edges is unclear. Progressive migration of the fascial edges toward the midline has been observed anecdotally, but objective evidence remains limited. The purpose of this study is to observe the effect of LVH repair on the rectus abdominus fascia.

METHODS

Patients undergoing LVH repair with defects > 10 cm in horizontal diameter were identified prospectively and enrolled. All were repaired laparoscopically with intraperitoneal placement of mesh (DualMesh, W.L. Gore and Associates) using a standard approach. Radio-opaque clips were placed at the fascial edges intraoperatively to mark the defect, and plain abdominal films were taken postoperatively (Time 1) to establish the initial distance between clips (measured in cm). A subsequent follow-up film was taken (Time 2), and the difference in clip distance per patient was recorded. Results were analyzed using a chi-squared test.

RESULTS

Twelve patients qualified for analysis and their results were compared. Mean fascial defect size was 15.1 cm (range 8.3-22.0). With respect to change in clip distance from Times 1 to 2, three events were observed: (1) Diminished (i.e. medialized), (2) Enlarged, or (3) No Change. Ten patients (83%) medialized, one patient enlarged, and one patient showed no change (chi2 (d.f. = 2) 9.17, p < 0.0023).

CONCLUSIONS

Medialization of the rectus abdominus fascia occurs in the majority of patients undergoing LVH repair. Causes for this phenomenon are unclear: however eliminating intrabdominal pressure with intraperitoneal mesh placement likely plays a role.

Construct validation of the ProMIS simulator using a novel laparoscopic suturing task

BACKGROUND

The use of simulation for minimally invasive surgery (MIS) skills training has many advantages over current traditional methods. One advantage of simulation is that it enables an objective assessment of technical performance. The purpose of this study was to determine whether the ProMIS augmented reality simulator could objectively distinguish between levels of performance skills on a complex laparoscopic suturing task.

METHODS

Ten subjects--five laparoscopic experts and five laparoscopic novices--were assessed for baseline perceptual, visio-spatial, and psychomotor abilities using validated tests. After three trials of a novel laparoscopic suturing task were performed on the simulator, measures for time, smoothness of movement, and path distance were analyzed for each trial. Accuracy and errors were evaluated separately by two blinded reviewers to an interrater reliability of >0.8. Comparisons of mean performance measures were made between the two groups using a Mann-Whitney U test. Internal consistency of ProMIS measures was assessed with coefficient alpha.

RESULTS

The psychomotor performance of the experts was superior at baseline assessment (p < 0.001). On the laparoscopic suturing task, the experts performed significantly better than the novices across all three trials (p < 0.001). They performed the tasks between three and four times faster (p < 0.0001), had three times shorter instrument path length (p < 0.0001), and had four times greater smoothness of instrument movement (p < 0.009). Experts also showed greater consistency in their performance, as demonstrated by SDs across all measures, which were four times smaller than the novice group. Observed internal consistency of ProMIS measures was high (alpha = 0.95, p < 0.00001).

CONCLUSIONS

Preliminary results of construct validation efforts of the ProMIS simulator show that it can distinguish between experts and novices and has promising psychometric properties. The attractive feature of ProMIS is that a wide variety of MIS tasks can be used to train and assess technical skills.

Memories that last in old age: motor skill learning and memory preservation

Using an automated test panel, age-associated declines in learning, remembering and performing a novel visuomotor task were assessed in 497 normal adults ranging from 18 to 95 years old. As predicted, task performance times slowed with increasing age in the cross-sectional portion of the study. However in the subsequent longitudinal study, while motor learning was significantly slower in adults over 62 years old, motor memory was pristinely preserved in normal adults from 18 to 95 years old. When tested 2 years after the first training session and without intervening rehearsal, mean performance times were retained and continued to improve by 10% in young adults and 13% in aged adults, reflecting long lasting preservation of motor memories. While the maximum lifetime of an unpracticed, novel motor memory in humans is not known, the present study suggests that new motor memories can be retained for at least 2 years without rehearsal in normal aged adults. This age-resistant component of motor memory stands in contrast to the well-known decrements in other motor and cognitive processes with human aging.

Correlation between perceptual, visuo-spatial, and psychomotor aptitude to duration of training required to reach performance goals on the MIST-VR surgical simulator

Given the dynamic nature of modern surgical education, determining factors that may improve the efficiency of laparoscopic training is warranted. The objective of this study was to analyze whether perceptual, visuo-spatial, or psychomotor aptitude are related to the amount of training required to reach specific performance-based goals on a virtual reality surgical simulator. Sixteen MS4 medical students participated in an elective skills course intended to train laparoscopic skills. All were tested for perceptual, visuo-spatial, and psychomotor aptitude using previously validated psychological tests. Training involved as many instructor-guided 1-hour sessions as needed to reach performance goals on a custom designed MIST-VR manipulation-diathermy task (Mentice AB, Gothenberg, Sweden). Thirteen subjects reached performance goals by the end of the course. Two were excluded from analysis due to previous experience with the MIST-VR (total n = 11). Perceptual ability (r = -0.76, P = 0.007) and psychomotor skills (r = 0.62, P = 0.04) significantly correlated with the number of trials required. Visuo-spatial ability did not significantly correlate with training duration. The number of trials required to train subjects to performance goals on the MIST-VR manipulation diathermy task is significantly related to perceptual and psychomotor aptitude.

Laparoscopic palliative surgery for complicated colorectal cancer

BACKGROUND

The aim of this study was to evaluate the feasibility and outcomes of the laparoscopic approach for the palliation of advanced complicated colorectal cancer (CRC).

METHODS

We reviewed 21 laparoscopic palliative procedures for emergent complications of advanced CRC between 1994 and 2002. Intraoperative complications, estimated blood loss, transfusions, operative times, time to first bowel movement, length of hospital stay, and postoperative complications were assessed.

RESULTS

Indications for surgery included perforation (n = 10), bleeding (n = 7), and obstruction (n = 4). A proximal diverting procedure was performed in all patients, and a concomitant colon resection was performed in 18 patients (86%). The mean operative time was 181 +/- 22 min. Estimated blood loss was 283 +/- 48 cc, with three patients (14%) requiring transfusions. The average length of hospital stay was 8.6 +/- 2 days, and time to first bowel movement was 61 +/- 9 h. The complication rate and the 30-day mortality rate were 33% and 0%, respectively.

CONCLUSION

A laparoscopic approach to address advanced CRC is safe and effective and should be considered part of the surgeon's armamentarium for the palliation of advanced complicated CRC.

Optimal management of the morbidly obese patient SAGES appropriateness conference statement

BACKGROUND

Obesity is a growing health problem that contributes to numerous life-threatening or disabling disorders, including coronary artery disease, hypertension, type 2 diabetes mellitus, hyperlipidemia, degenerative joint disease, and obstructive sleep apnea. Significant weight reduction in the morbidly obese improves or reverses associated illness and benefits well-being. The purpose of the SAGES Appropriateness Conference was to summarize the state of the art for open and laparoscopic operations for the morbidly obese.

METHODS

The English literature comparing bariatric procedures was reviewed and grouped by level of evidence by three surgeons (BS, LV, and CC). From more than 1,500 articles, all conference participants were provided with reprints and table summaries of no less than 50 selected manuscripts. Ten experts were requested to present reviews and make evidence-based arguments for and against the open and laparoscopic approaches in written format. An expert panel of six surgeons, including an ethicist and patient, commented on implications of data presented. The finalized statement was e-mailed to all participants for approval and comment.

RESULTS

Consensus statements were achieved on various aspects of morbid obesity, including indications for surgery, resolution of comorbid illnesses with significant weight loss, and the importance of committed bariatric program. Our panel of experts agreed, in general, to the advantages of laparoscopic approaches compared to open operations in skilled hands.

CONCLUSIONS

Laparoscopic Roux-en-Y gastric bypass (RYGB) affords improved short-term recovery compared to open gastric bypass. Laparoscopic adjustable banding can be performed with lower average mortality than either RYGB or any of the malabsorptive operations, and it produces variable degrees of short-term weight loss. Prospective randomized trials are needed to compare gastric bypass, malabsorptive, and restrictive procedures.

Discriminative validity of the Minimally Invasive Surgical Trainer in Virtual Reality (MIST-VR) using criteria levels based on expert performance

BACKGROUND

Increasing constraints on the time and resources needed to train surgeons have led to a new emphasis on finding innovative ways to teach surgical skills outside the operating room. Virtual reality training has been proposed as a method to both instruct surgical students and evaluate the psychomotor components of minimally invasive surgery ex vivo.

METHODS

The performance of 100 laparoscopic novices was compared to that of 12 experienced (>50 minimally invasive procedures) and 12 inexperienced (<10 minimally invasive procedures) laparoscopic surgeons. The values of the experienced surgeons' performance were used as benchmark comparators (or criterion measures). Each subject completed six tasks on the Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) three times. The outcome measures were time to complete the task, number of errors, economy of instrument movement, and economy of diathermy.

RESULTS

After three trials, the mean performance of the medical students approached that of the experienced surgeons. However, 7-27% of the scores of the students fell more than two SD below the mean scores of the experienced surgeons (the criterion level).

CONCLUSIONS

The MIST-VR system is capable of evaluating the psychomotor skills necessary in laparoscopic surgery and discriminating between experts and novices. Furthermore, although some novices improved their skills quickly, a subset had difficulty acquiring the psychomotor skills. The MIST-VR may be useful in identifying that subset of novices.

Laparoscopic vs open resection for the treatment of diverticular disease

INTRODUCTION

The aim of this study was to evaluate whether laparoscopic colon resection (LCR) offers any advantages over open colon resection (OCR) in the treatment of diverticular disease.

METHODS

Between 1992 and 2002, 95 patients underwent LCR and 80 patients underwent OCR for the treatment of diverticular disease. Demographics, details of operative procedure, outcome, and pathology were compared.

RESULTS

Patients in both groups were matched for age, sex, body mass index, history of previous abdominal operations, comorbidities, location of the disease, and presence of complications. LCR resulted in significantly less estimated blood loss and postoperative complications, shorter time to first bowel movement, and shorter length of stay than the OCR. There was no difference in operative time, intraoperative complications, mortality rates between groups.

CONCLUSIONS

LCR is a safe and effective approach for the treatment of patients with diverticular disease. It results in less estimated blood loss, shorter time to first bowel movement, less postoperative complications, and shorter length of hospital stay.

Comparative results of endoluminal gastroplasty and laparoscopic antireflux surgery for the treatment of GERD

BACKGROUND

Transoral endoluminal gastroplasty (EG) by the Bard Endocinch device is available for the treatment of gastroesophageal reflux disease (GERD). This study assessed the early (<or=12 months) outcomes in patients undergoing EG performed by one gastroenterologist compared with another set of patients referred by the same gastroenterologist for laparoscopic antireflux surgery (LAS) at a foregut surgery center.

METHODS

From June 2000 to July 2002, 87 consecutive patients cared for by a single gastroenterologist were diagnosed with refractory GERD and underwent either EG (n = 47) or referral for LAS (n = 40). Preoperative evaluation included symptom assessment, pH studies, and motility studies. Outcomes were assessed by symptomatic improvement and dependence on anti-acid medications. Data analyzed by chi-square or Mann-Whitney tests are reported as mean +/- SEM.

RESULTS

Preoperative symptom duration, Johnson-DeMeester (JD) score, % time pH < 4, and reflux episodes were statistically similar in both treatment groups. The follow-up times for EG and LAS groups were 7.3 +/- 0.9 and 8 +/- 0.4 months, respectively. Of EG patients, 94% were available for follow-up, and all LAS patients had follow-up data. Overall, 66% of patients were satisfied with EG as compared to 93% after LAS (p = 0.1). Postoperative PPI/motility agent use was 32% for EG and 13% for LAS (p = 0.03). Identifiable causes of EG failure were premature procedure termination due to hypoxia or bleeding (three patients), intractable vomiting (two patients), and delayed gastric emptying (five patients). Three EG patients subsequently had LAS within 6 months of the procedure.

CONCLUSIONS

LAS offers greater reduction in medication use than EG, as well as more durable patient satisfaction. Benefits of EG may include short-term symptomatic improvement while considering definitive surgical management.

Preoperative factors predictive of complicated postoperative management after Roux-en-Y gastric bypass for morbid obesity

INTRODUCTION

This study was undertaken to determine preoperative predictive factors of complicated postoperative management after Roux-en-Y gastric bypass (RYGB) for morbid obesity.

METHODS

Between January 1999 and January 2002, 158 patients who underwent a RYGB received a standardized preoperative evaluation and data were collected prospectively. Complicated postoperative management was defined as patients requiring postoperative ICU admission for > or =48 h, or those needing transfer from the floor to the ICU. Patients with complicated management were compared with those in whom ICU admission was not necessary.

RESULTS

Twenty-three patients (14.5%) required prolonged ICU admission (mean stay of 6.3 +/- 1.7 days). After multivariate analysis, body mass index (BMI) >50 kg/m2, forced expiratory volume (FEV1) <80% predicted, previous abdominal surgeries, and abnormal EKG were found to be independently associated with an increased likelihood of complicated postoperative care.

CONCLUSION

BMI >50 kg/m2, FEV1 <80% predicted, previous abdominal surgeries, and abnormal EKG increase the likelihood of complicated postoperative management after RYGB for morbid obesity.

Can current technology be integrated to facilitate laparoscopic living donor hepatectomy?

BACKGROUND

Living donor hepatectomy (LDH) is a technically demanding procedure that is an alternative for providing livers for transplantation. Unlike liver resections for other pathology, LDH requires preservation of the major vessels and biliary tree. This study was performed to determine if current technology can be integrated to perform laparoscopic LDH.

METHODS

Six adult sheep underwent laparoscopic LDH of the left lateral segment under general anesthesia. Instruments utilized included standard dissecting instruments, ultrasound, ultrasonic dissectors, CUSA, the TissueLink Floating Ball, and endoscopic staplers.

RESULTS

LDH-harvested liver grafts were 44% of whole liver weight. Estimated blood loss was 300 cc. Warm ischemia time was 5-7 min. Grafts were delivered through 18-cm abdominal wounds. Major vessels and biliary anatomy were positively identified in the grafts.

CONCLUSIONS

Laparoscopic LDH can be performed with available technology. Theoretical advantages include reduced liver manipulation and smaller wound size.