Modification of physicochemical properties of chitosan to improve its pharmaceutical and agrochemical potential applications

Chitosan has received much more attention as a functional biopolymer with applications in pharmaceuticals, agricultural, drug delivery systems and cosmetics. The objectives of present investigation were to carry out modification of chitosan for enhancement of aqueous solubility, which will impart increased solubility and dissolution rate of poorly soluble drug itraconazole (ITZ) and also evaluate the modified chitosan for soyabean seed germination studies. The modification of chitosan was accomplished through the antisolvent precipitation method; employing five carboxylic acids. The resulting products were assessed for changes in molecular weight, degree of deacetylation, solubility and solid state characterization. Subsequently, the modified chitosan was complexed with itraconazole using the co-grinding technique. The prepared formulations were evaluated for solubility, FTIR (Fourier-transform infrared spectroscopy), PXRD (Powder X-ray diffraction), in-vitro dissolution studies. Furthermore the effect of modified chitosan has been evaluated on soybean seed germination. Results demonstrated that, modified chitosan improves self and solubility of itraconazole by six folds. As there was increased degree of deacetylation of chitosan leads to improvement in solubility. The results of FTIR showed the slight shifting of peaks in co-grind formulations of itraconazole. Formulations showed reduction in crystallinity of drug which leads to enhancement in dissolution rate as compared to pure itraconazole. Retention of property of seed germination was observed with modified chitosan at optimum concentration of 3 % w/v, with benefit of enhanced aqueous solubility of chitosan. This positive result paves the way for the advancement of pharmaceutical and agrochemical products employing derivatives of chitosan.

Predicting the Societal Value of Lecanemab in Early Alzheimer's Disease in Japan: A Patient-Level Simulation

INTRODUCTION

Alzheimer's disease (AD), a neurodegenerative disorder that progresses from mild cognitive impairment (MCI) to dementia, is responsible for significant burden on caregivers and healthcare systems. In this study, data from the large phase III CLARITY AD trial were used to estimate the societal value of lecanemab plus standard of care (SoC) versus SoC alone against a range of willingness-to-pay (WTP) thresholds from a healthcare and societal perspective in Japan.

METHODS

A disease simulation model was used to evaluate the impact of lecanemab on disease progression in early AD based on data from the phase III CLARITY AD trial and published literature. The model used a series of predictive risk equations based on clinical and biomarker data from the Alzheimer's Disease Neuroimaging Initiative and Assessment of Health Economics in Alzheimer's Disease II study. The model predicted key patient outcomes, including life years (LYs), quality-adjusted life years (QALYs), and total healthcare and informal costs of patients and caregivers.

RESULTS

Over a lifetime horizon, patients treated with lecanemab plus SoC gained an additional 0.73 LYs compared with SoC alone (8.50 years vs. 7.77 years). Lecanemab, with an average treatment duration of 3.68 years, was found to be associated with a 0.91 increase in patient QALYs and a total increase of 0.96 when accounting for caregiver utility. The estimated value of lecanemab varied according to the WTP thresholds (JPY 5-15 million per QALY gained) and the perspective employed. From the narrow healthcare payer's perspective, it ranged from JPY 1,331,305 to JPY 3,939,399. From the broader healthcare payer's perspective, it ranged from JPY 1,636,827 to JPY 4,249,702, while from the societal perspective, it ranged from JPY 1,938,740 to JPY 4,675,818.

CONCLUSION

The use of lecanemab plus SoC would improve health and humanistic outcomes with reduced economic burden for patients and caregivers with early AD in Japan.

A Path to Improved Alzheimer's Care: Simulating Long-Term Health Outcomes of Lecanemab in Early Alzheimer's Disease from the CLARITY AD Trial

INTRODUCTION

Alzheimer's disease (AD), a progressive neurodegenerative disease, is the main cause of dementia and one of the leading causes of death for elderly people in the USA. Lecanemab is a humanized IgG1 monoclonal antibody targeting amyloid protofibrils for the treatment of early AD [i.e., mild cognitive impairment (MCI) or mild AD dementia]. In a recent 18-month phase III trial, using a double-blind, placebo-controlled design, lecanemab treatment led to reduced brain amyloid burden and significant improvements in cognitive and functional abilities in individuals with early AD.

METHODS

An evidence-based patient-level disease simulation model was updated to estimate the long-term health outcomes of lecanemab plus standard of care (SoC) compared to SoC alone in patients with early AD and evidence of brain amyloid burden, using recent phase III trial data and published literature. The disease progression is described by changes in the underlying biomarkers of AD, including measures of amyloid and tau, and their connection to the clinical presentation of the disease assessed through various patient-level scales of cognition and function.

RESULTS

Lecanemab treatment was estimated to slow the progression of AD to moderate and severe stages and reduce the time spent in these more advanced states. In individuals with early AD, lecanemab plus SoC was associated with a gain of 0.71 quality-adjusted life-years (QALYs), a 2.95-year delay in mean time to progression to AD dementia, a reduction of 0.11 years in institutional care, and an additional 1.07 years in community care as shown in the base-case study. Improved health outcomes were demonstrated with lecanemab treatment when initiated earlier based on age, disease severity, or tau pathology, resulting in estimated gains in QALYs ranging from 0.77 to 1.09 years, compared to 0.4 years in the mild AD dementia subset, as shown by the model.

CONCLUSION

The study findings demonstrate the potential clinical value of lecanemab for individuals with early AD by slowing down disease progression and prolonging time in earlier stages of disease, which significantly benefits not only patients and caregivers but also society overall.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03887455.

Estimated Societal Value of Lecanemab in Patients with Early Alzheimer's Disease Using Simulation Modeling

INTRODUCTION

Alzheimer's disease (AD) is a progressive neurodegenerative disorder associated with memory, cognitive, and behavioral deficits, and brings significant economic burden on caregivers and healthcare systems. This study aims to estimate the long-term societal value of lecanemab plus standard of care (SoC) versus SoC alone, corresponding to a range of willingness-to-pay (WTP) thresholds based on the phase III CLARITY AD trial readouts from both the US payer and societal perspectives.

METHODS

An evidence-based model was developed to simulate the effects of lecanemab on disease progression in early AD using interconnected predictive equations based on longitudinal clinical and biomarker data derived from the Alzheimer's Disease Neuroimaging Initiative (ADNI). The model was informed with the results of the phase III CLARITY AD trial and published literature. Key model outcomes included patient life-years (LYs), quality-adjusted life-years (QALYs), and total costs of both the direct and indirect costs of patients and caregivers over a lifetime horizon.

RESULTS

Patients treated with lecanemab plus SoC gained an additional 0.62 years of life versus SoC alone (6.23 years vs. 5.61 years). The mean time on lecanemab was 3.91 years, and the treatment was associated with an increase in patient QALYs of 0.61 and an increase in total QALYs of 0.64 when both patient and caregiver utilities were considered. The model estimated that the annual value of lecanemab for the US payer perspective was US$18,709-35,678 ($19,710-37,351 for societal perspective) at the WTP threshold of $100,000-200,000 per QALY gained, respectively. Scenario analyses of patient subgroups, time horizon, input sources, treatment stopping rules, and treatment dosing were conducted to explore the impact of alternative assumptions on the model results.

CONCLUSION

The economic study suggested that lecanemab plus SoC would improve health and humanistic (quality of life) outcomes and reduce economic burden for patients and caregivers in early AD.

The Potential Value-Based Price of a Multi-Cancer Early Detection Genomic Blood Test to Complement Current Single Cancer Screening in the USA

BACKGROUND

Multi-cancer early detection (MCED) testing could increase detection of cancer at early stages, when survival outcomes are better and treatment costs are lower, but is expected to increase screening costs. This study modeled an MCED test for 19 solid cancers in a US population and estimated the potential value-based price (the maximum price to meet a given willingness to pay) of the MCED test plus current single cancer screening (usual care) compared to usual care alone from a third-party payer perspective over a lifetime horizon.

METHODS

A hybrid cohort-level state-transition and decision-tree model was developed to estimate the clinical and economic outcomes of annual MCED testing between age 50 and 79 years. The impact on time and stage of diagnosis was computed using an interception modeling approach, with the consequences of cancer modeled based on stage at diagnosis. The model parameters were mainly sourced from the literature, including a published case-control study to inform MCED test performance. All costs were inflated to 2021 US dollars.

RESULTS

Multi-cancer early detection testing shifted cancer diagnoses to earlier stages, with a 53% reduction in stage IV cancer diagnoses, resulting in longer overall survival compared with usual care. Addition of MCED decreased per cancer treatment costs by $5421 and resulted in a gain of 0.13 and 0.38 quality-adjusted life-years across all individuals in the screening program and those diagnosed with cancer, respectively. At a willingness-to-pay threshold of $100,000 per quality-adjusted life-year gained, the potential value-based price of an MCED test was estimated at $1196. The projected survival of individuals diagnosed with cancer and the number of cancers detected at an earlier stage by MCED had the greatest impact on outcomes.

CONCLUSIONS

An MCED test with high specificity would potentially improve long-term health outcomes and reduce cancer treatment costs, resulting in a value-based price of $1196 at a $100,000/quality-adjusted life-year willingness-to-pay threshold.

The Potential Economic Value of Lecanemab in Patients with Early Alzheimer's Disease Using Simulation Modeling

Introduction

Alzheimer’s disease (AD) is a progressive, neurodegenerative disease that affects memory, thinking, and behavior and places a substantial economic burden on caregivers and healthcare systems. This early-phase study aimed to model lecanemab, a humanized monoclonal antibody targeting amyloid protofibrils, for patients with early AD, and estimate the potential value-based price (VBP) of lecanemab + standard of care (SoC) compared to SoC alone given an expected product profile of lecanemab informed by data from a phase II trial from payer and societal perspectives using a broad range of willingness-to-pay (WTP) thresholds in the USA.

Methods

A disease simulation model was used to capture how key AD pathology components relate to the clinical and economic presentation of AD. The effects of disease modification and early intervention on disease progression were simulated on the basis of BAN2401-G000-201 trial data as well as published literature. Model outcomes included patient and caregiver quality-adjusted life years (QALYs), total life years, and total care costs including direct medical and non-medical costs for healthcare resource use and indirect costs for caregiving over a lifetime horizon.

Results

Lecanemab + SoC was predicted to result in a gain of 0.61 QALYs (societal, 0.64) and a $8707 decrease in total non-treatment costs (societal, $11,214) vs. SoC alone for patients with early AD. For a WTP threshold range of $50,000 to $200,000 per QALY gained, the potential annual VBP of lecanemab was estimated at $9249 (societal, $10,400) to $35,605 (societal, $38,053), respectively. Other patient subsets, treatment stopping rules, and dosing regimens were used to assess the sensitivity of the VBP estimates.

Conclusion

The early model predicted that lecanemab would potentially improve long-term health outcomes and reduce formal and informal care costs, resulting in a range of VBPs that reflect the value of lecanemab to society.

Long-Term Health Outcomes of Lecanemab in Patients with Early Alzheimer's Disease Using Simulation Modeling

Introduction

Alzheimer’s disease (AD) is a progressive, neurodegenerative disease and is the most common cause of dementia. Lecanemab is a humanized monoclonal antibody targeting amyloid protofibrils for the treatment of early AD. In the phase II BAN2401-G000-201 trial (NCT01767311), lecanemab reduced amyloid accumulated in the brain and slowed progression on key global and cognitive scales evaluating efficacy after 18 months of treatment.

Methods

A disease simulation model was used to predict the long-term clinical outcomes of lecanemab for patients with early AD [i.e., mild cognitive impairment (MCI) due to AD and mild AD dementia] on the basis of BAN2401-G000-201 trial data and published literature. The model captures the pathophysiology and management of AD, with a focus on simulating the effects of disease modification and early intervention on disease progression. The model compares lecanemab in addition to standard of care (SoC) versus SoC alone.

Results

Lecanemab treatment was estimated to slow the rate of disease progression, resulting in an extended duration of MCI due to AD and mild AD dementia and shortened duration in moderate and severe AD dementia. The mean time to mild, moderate, and severe AD dementia was longer for patients in the lecanemab + SoC group than for patients in the SoC group by 2.51, 3.13, and 2.34 years, respectively. On base-case analysis, lecanemab was associated with 0.73 incremental life years (LY) and 0.75 incremental quality-adjusted LYs (QALY), and the caregiver QALYs lost was reduced by 0.03 years. The model also predicted a lower lifetime probability of admission to institutional care in lecanemab + SoC versus SoC group (25% versus 31%).

Conclusion

The model results demonstrate the potential clinical value of lecanemab for patients with early AD and how it can slow the rate of disease progression and reduce the lifetime probability for institutionalized care.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-022-00350-y.

Concomitant pulmonary disease is common among patients with extrapulmonary TB

BACKGROUND :

Microbiologic screening of extrapulmonary TB (EPTB) patients could inform recommendations for aerosol precautions and close contact prophylaxis. However, this is currently not routinely recommended in India. Therefore, we estimated the proportion of Indian patients with EPTB with microbiologic evidence of pulmonary TB (PTB).

METHODS :

We characterized baseline clinical, radiological and sputum microbiologic data of 885 adult and pediatric TB patients in Chennai and Pune, India, between March 2014 and November 2018.

RESULTS :

Of 277 patients with EPTB, enhanced screening led to the identification of 124 (45%) with concomitant PTB, including 53 (19%) who reported a cough >2 weeks; 158 (63%) had an abnormal CXR and 51 (19%) had a positive sputum for TB. Of 70 participants with a normal CXR and without any cough, 14 (20%) had a positive sputum for TB. Overall, the incremental yield of enhanced screening of patients with EPTB to identify concomitant PTB disease was 14% (95% CI 12–16).

CONCLUSIONS :

A high proportion of patients classified as EPTB in India have concomitant PTB. Our results support the need for improved symptom and CXR screening, and recommends routine sputum TB microbiology screening of all Indian patients with EPTB.

Modeling long-term health and economic implications of new treatment strategies for Parkinson's disease: an individual patient simulation study

Background: Simulation modeling facilitates the estimation of long-term health and economic outcomes to inform healthcare decision-making. Objective: To develop a framework to simulate progression of Parkinson's disease (PD), capturing motor and non-motor symptoms, clinical outcomes, and associated costs over a lifetime. Methods: A patient-level simulation was implemented accounting for individual variability and interrelated changes in common disease progression scales. Predictive equations were developed to model progression for newly diagnosed patients and were combined with additional sources to inform long-term progression. Analyses compared a hypothetical disease-modifying therapy (DMT) with a standard of care to explore the drivers of cost-effectiveness. Results: The equations captured the dependence between the various measures, leveraging prior values and rates of change to obtain realistic predictions. The simulation was built upon several interrelated equations, validated by comparison with observed values for the Movement Disorder Society Unified PD Rating Scale (MDS-UPDRS) and UPDRS subscales over time. In a case study, disease progression rates, patient utilities, and direct non-medical costs were drivers of cost-effectiveness. Conclusions: The developed equations supported the simulation of early PD. This model can support conducting simulations to inform internal decision-making, trial design, and strategic planning early in the development of new DMTs entering clinical trials.

Measuring TB drug levels in the hair in adults and children to monitor drug exposure and outcomes

INTRODUCTION: Testing for anti-TB drugs in small hair samples may serve as a non-invasive tool to measure cumulative drug exposure and/or adherence, as these determine treatment success. We aimed to assess how well hair assays of TB drugs predict TB treatment outcomes.METHODS: A small thatch of hair, ~30 strands, was cut from the occipital region in adults and children from a prospective TB cohort in India. Isoniazid (INH), acetyl-INH and pyrazinamide (PZA) were extracted from the hair samples and quantified using liquid-chromatography-tandem mass spectrometry. The relationship between drug concentrations in hair and time to unfavourable outcomes was assessed using Cox-proportional hazards regression models.RESULTS: A two-fold increase in hair acetyl-INH concentrations in the 264 participants in our cohort with hair assays for TB drugs indicated a lower hazard of unfavourable TB treatment outcomes (aHR 0.67, 95%CI 0.44-1.02) and TB treatment failure (aHR 0.65, 95%CI 0.42-1.01). Higher summed concentrations (a summed measure of INH and acetyl-INH) indicated a lower hazard of treatment failure (aHR 0.69, 95%CI 0.45-1.05)CONCLUSION: Hair levels of INH and its metabolite may predict TB treatment outcomes, indicating the potential utility of this measure to assess and optimise TB treatment outcomes.

Cost-effectiveness of valbenazine compared with deutetrabenazine for the treatment of tardive dyskinesia

AIMS

To evaluate clinical and economic outcomes associated with valbenazine compared with deutetrabenazine in patients with tardive dyskinesia (TD) using a model that accounts for multiple dimensions of patient health status.

MATERIALS AND METHODS

A discretely integrated condition event model was developed to evaluate the cost-effectiveness of treatment with valbenazine and deutetrabenazine in a synthetic cohort of 1,000 patients with TD who were receiving antipsychotic medication to treat an underlying psychiatric disorder. Clinical inputs were derived from relevant clinical trials or from publicly available sources. Patients were assessed over 1 year using ≥50% improvement from baseline in Abnormal Involuntary Movement Scale (AIMS) total score as the primary definition of response. Response at 1 year using Clinical Global Impression of Change (CGIC) score ≤2 was also assessed. Health outcomes included quality-adjusted life years (QALYs), life years, proportion responding to treatment at 1 year, and number of psychiatric relapses.

RESULTS

Regardless of the definition used for response, patients treated with valbenazine were more likely to have responded to treatment at 1 year, lived longer, and accrued more QALYs than patients who received deutetrabenazine. Using the AIMS response criterion, the incremental cost-effectiveness ratio was $9,951/QALY for valbenazine compared with deutetrabenazine. By comparison, using the CGIC response criterion valbenazine dominated deutetrabenazine with valbenazine-treated patients accumulating more QALYs (3.4 vs 3.3 years) and incurring lower lifetime costs ($252,311 vs $283,208) than deutetrabenazine-treated patients.

LIMITATIONS

There are no head-to-head trials of valbenazine and deutetrabenazine, so probabilities of response used in the model were calculated based on an indirect treatment comparison of results from individual trials with one drug or the other, using only those metrics reported across trials.

CONCLUSIONS

In patients with TD, treatment with valbenazine is highly cost-effective compared with deutetrabenazine.

Efficiency Model of Cladribine Tablets Versus Infusion-Based Disease-Modifying Drugs for Patients with Relapsing-Remitting Multiple Sclerosis

INTRODUCTION

To develop a simulation model assessing the efficiency of using cladribine tablets versus infusion-based disease-modifying drugs (DMDs) for the treatment of relapsing-remitting multiple sclerosis (RRMS) from a facility perspective in the UK.

METHODS

A scheduling algorithm was developed to simulate day-case admissions and calculate the mean changes to resource use and time burden for patients in a facility that transitions from infusion-based treatments to cladribine tablets over 1 year. Model inputs and assumptions were based on previous research and expert opinion. Model validation and quality checks were performed and additional scenario analyses were also conducted.

RESULTS

The model successfully scheduled all infusion treatments in the base case and no patients were left off the schedule as a result of lack of capacity. Modeled base-case outcomes increased in future scenarios owing to a 35% increase in demand. The introduction of cladribine tablets reduced these impacts. Specifically, the difference in mean daily utilization was reduced in the future scenario from 13% to 3% as 8% of patients moved to cladribine tablets; annual administration costs decreased by 96% and annual time burden decreased by 90%. Results from additional scenarios showed the largest benefits from switching current infusion patients to cladribine tablets were realized in facilities having moderate to high resource utilization.

CONCLUSIONS

This model provides facility decision-makers the ability to assess the efficiency of using cladribine tablets rather than an infusion-based DMD. The simulation quantified the benefits gained from reducing the burden on facility resources by switching some patients with RRMS from infusion-based DMDs to cladribine tablets. Overall, modeled outcomes increased in future scenarios owing to an increase in demand, although the introduction of cladribine tablets reduced this impact.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Assessment of the Xpert assay among adult pulmonary tuberculosis suspects with and without diabetes mellitus

SETTING: Pune and Pimpri-Chinchwad Municipal Corporation area, Maharashtra State, India.OBJECTIVE: To assess the sensitivity and specificity of the Xpert® MTB/RIF assay among adults with suspected pulmonary tuberculosis (PTB) and with or without diabetes (DM).DESIGN: As part of a prospective cohort study, we screened 2359 adults presumed to have PTB with no history of TB. All individuals underwent testing for two sputum smears, culture, Xpert, glycated haemoglobin and fasting blood sugar. We calculated sensitivity and specificity of Xpert by comparing it with TB sputum culture result as a gold standard.RESULTS: Among screened individuals, 483 (20%) were diagnosed with DM and 1153 (49%) with pre-DM; 723 (31%) had no DM. Overall sensitivity of Xpert was 96% (95%CI 95–97) and specificity was 91% (95%CI 89–93). Xpert sensitivity was significantly higher among DM group (98%) than in the ‘No DM' (95%; P < 0.01) and pre-DM (96%; P < 0.05) groups. Among sputum smear-negative individuals, Xpert sensitivity was higher in the DM group than in the No DM (92% vs. 82%; P = 0.054) and pre-DM group (92% vs. 82%; P = 0.037).CONCLUSION: High sensitivity and specificity of Xpert underscores the need for its rapid scale up for the early detection of TB in settings with a high dual burden of TB and DM.

[Endovascular aneurysm repair (EVAR) : Complication management]

A variety of complications may be experienced during or after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA). Acute procedure-related complications include injury to the access vessels, improper endograft placement, ischaemic and systemic complications as well as the postimplantation syndrome. Femoral pseudoaneurysms, endograft migration, kinking or occlusion, endoleaks and endograft infection are complications that have been observed at follow-up. Meticulous patient selection and preprocedural work-up can reduce the incidence of these complications. The majority of the complications, acute as well those at follow-up, can be dealt with endoluminally. It is of essence, however, that a wide variety of catheters, guidewires, stents, stent-grafts and embolics are readily available in the repertoire of the interventionalist. In a small number of patients with endograft occlusion or infection or with bleeding complications/pseudoaneurysms of the access vessels, open surgical intervention may become necessary. To obtain optimal results, close interdisciplinary co-operation, especially between the interventionist, the vascular surgeon and the anaesthetist is mandatory.

Comparative Evaluation of N-Butyl Cyanoacrylate and Silk Sutures on Healing of Periodontal Flaps: A Clinico Histological Evaluation

Background The periodontal flap is one of the most frequently employed procedures. Closure of reflected flap is important step in flap surgery. Black silk sutures are most often used material in routine surgical procedures. These suture materials demand more time and effort and expertise from the surgeon. Tissue adhesives have been developed as alternatives to overcome these problems such as cyanoacrylates. Objective The present study is an attempt to compare effectiveness of the black silk suture with cyanoacrylate adhesives in closing reflected periodontal flap. Method Thirty systemically healthy patients who underwent bilateral flap surgery were given 3-0 black silk sutures on one side and N-butyl cyanoacrylate adhesive on the other side to close a surgical incision. All the participants in the study were recalled on the seventh, 21st, 42nd day. Participants were evaluated for healing and plaque accumulation by assessing the gingival index, plaque index, wound healing index. Biopsy specimens were obtained on seventh and 42nd postoperative day. Result The amount of inflammation was less during the first week of healing when cyanoacrylate was compared with silk. However, over a period of 21 days to 42 days, the sites treated with both the materials showed similar healing patterns without any significant difference in the evaluated parameter. Conclusion The result of the study showed that the use of cyanoacrylate for the closure of periodontal flaps results in better initial post-operative healing as compared to closure with silk suture and that this method of closure can be advocated in a routine surgical periodontal practice.

The Kissing Balloons Technique

Whereas dilatation of a single stenosis of the main renal artery is a routine intervention, a narrowing of the renal artery at its bifurcation extending into the branch arteries poses a more complex problem. The procedural risks of renal artery dilatation are compounded by the danger of occlusion of one of the branch arteries during maneuvers to dilate the other. Long-term results of surgical vascular reconstruction at a renal artery bifurcation are not satisfactory. Untreated, these stenoses lead to intractable hypertension and impairment or loss of renal function. We present a patient with hypertension and impaired function of the right kidney on account of a renal arterial bifurcation stenosis. Using a bilateral transfemoral arterial approach 2 balloon catheters were simultaneously placed into the origins of the renal artery branches and both arteries were successfully dilated by the kissing balloons technique. This method provides an elegant alternative to difficult surgery to save an endangered kidney.

Risk of cancer incidence before the age of 15 years after exposure to ionising radiation from computed tomography: results from a German cohort study

The aim of this cohort study was to assess the risk of developing cancer, specifically leukaemia, tumours of the central nervous system and lymphoma, before the age of 15 years in children previously exposed to computed tomography (CT) in Germany. Data for children with at least one CT between 1980 and 2010 were abstracted from 20 hospitals. Cancer cases occurring between 1980 and 2010 were identified by stochastic linkage with the German Childhood Cancer Registry (GCCR). For all cases and a sample of non-cases, radiology reports were reviewed to assess the underlying medical conditions at time of the CT. Cases were only included if diagnosis occurred at least 2 years after the first CT and no signs of cancer were recorded in the radiology reports. Standardised incidence ratios (SIR) using incidence rates from the general population were estimated. The cohort included information on 71,073 CT examinations in 44,584 children contributing 161,407 person-years at risk with 46 cases initially identified through linkage with the GCCR. Seven cases had to be excluded due to signs possibly suggestive of cancer at the time of first CT. Overall, more cancer cases were observed (O) than expected (E), but this was mainly driven by unexpected and possibly biased results for lymphomas. For leukaemia, the SIR (SIR = O/E) was 1.72 (95 % CI 0.89-3.01, O = 12), and for CNS tumours, the SIR was 1.35 (95 % CI 0.54-2.78, O = 7). Despite careful examination of the medical information, confounding by indication or reverse causation cannot be ruled out completely and may explain parts of the excess. Furthermore, the CT exposure may have been underestimated as only data from the participating clinics were available. This should be taken into account when interpreting risk estimates.

[The simultaneous appearance of three uncommon tumours]

A 70-year-old woman presented with nasal obstruction and pain projecting onto the left cheek. The face seemed asymmetric including exophthalmus on the right side. Nasal endoscopic inspection revealed a sarcomatous tumor located on the middle turbinate. The CT showed that the tumor filled the left maxillary sinus completely and had eroded the maxillary bone. In addition, a round, sharply defined intraorbital neoplasm on the right side was identified in the contrast-enhanced MRI. Histological examination of the extirpated intraorbital tumour showed a neurilemmoma. A tissue biopsy of the intranasal tumour falsely suggested an intestinal adenocarcinoma. Multiple neoplasms suspicious of disseminated lung metastases were detected in the CT of the thorax. One round lesion removed by thoracoscopy revealed a carcinoid. The intranasal tumour was excised completely and the histology proved beyond doubt an inverted papilloma.

[Diagnosis of and therapy for hepatocellular carcinoma]

The interdisciplinary guidelines at the S3 level on the diagnosis of and therapy for hepatocellular carcinoma (HCC) constitute an evidence- and consensus-based instrument that is aimed at improving the diagnosis of and therapy for HCC since these are very challenging tasks. The purpose of the guidelines is to offer the patient (with suspected or confirmed HCC) adequate, scientifically based and up-to-date procedures in diagnosis, therapy and rehabilitation. This holds not only for locally limited or focally advanced disease but also for the existence of recurrences or distant metastases. Besides making a contribution to an appropriate health-care service, the guidelines should also provide the foundation for an individually adapted, high-quality therapy. The explanatory background texts should also enable non-specialist but responsible colleagues to give sound advice to their patients concerning specialist procedures, side effects and results. In the medium and long-term this should reduce the morbidity and mortality of patients with HCC and improve their quality of life.

Thorakale Aorten-Stentgraftimplantation

BACKGROUND AND OBJECTIVE

Endovascular stent-graft placement is emerging as a novel therapeutic option in patients with disease of the descending thoracic aorta. Quality standards for performing stent-graft procedures as well as for pre- and postoperative patient management are lacking, so far. It was the aim of this present survey to assess the current therapeutic standard of thoracic aortic stent-graft placement in Germany.

METHODS

In a nationwide survey, a total of 206 vascular surgical, radiologic, cardiologic, and cardiothoracic surgical departments were contacted. Data concerning preoperative procedure planning, logistics, practical/technical issues of stent-graft placement, and postoperative patient management were evaluated using a standardized questionnaire comprising 29 items. Data analysis was performed using univariate analysis.

RESULTS

184 (89.3 %) of the 206 departments participated in the survey. Of these, 71 centers reported intending to perform or having performed thoracic aortic stent-graft placement. The survey overall represents 2267 endovascular stent-graft procedures performed in Germany between 1997/98 and 2003. On average, 7.4 stent-graft procedures/year were performed by each center, with half the centers performing fewer than 5 procedures/year. Thoracic aortic aneurysms was the main indication for endovascular stent-graft placement, followed by aortic dissection. There were significant differences between the different medical specialties which perform stent-graft procedures with respect to indications, choice of preoperative and intraoperative imaging methods, and technical equipment. There was strong agreement between the different centers concerning the necessity of a life-long follow-up after stent-graft placement, with computed tomography being the preferred imaging technique (90 % of centers).

CONCLUSION

The present survey documents an increasing use of endovascular stent-graft placement in patients with disease of the descending thoracic aorta. There were differences regarding the technical execution of this procedures between specialties with respect to indication, procedure planning, and practical-technical aspects of stent-graft placement.

Chemoocclusion vs chemoperfusion for treatment of advanced hepatocellular carcinoma: a randomised trial

AIMS

Transarterial chemoembolization (TACE) can be associated with considerable toxicity and treatment-associated mortality. Transient transarterial chemoocclusion (TACO) using degradable starch microspheres (DSM) has been proposed as a potentially safer alternative while maintaining anti-tumour efficiency. In a randomised phase II trial TACO was compared to transarterial chemoperfusion without DSM (TACP).

METHODS

Seventy-four patients with advanced HCC were randomised to two treatment arms: (i) TACO (600-1200 mg DSM) and (ii) TACP. In both arms regional chemotherapy consisted of cisplatin (100 mg/m2) and doxorubicin (60 mg/m2). Both arms were corresponding in terms of age, gender, liver performance state, and tumour-stage. A maximum of six treatment cycles was applied in monthly intervals. Follow-up was performed in terms of tumour response, time to progression, survival and quality of life.

RESULTS

Tumour response rates did not differ significantly between the two treatment arms, however, there was a tendency towards higher response rates in the TACO arm (TACO vs TACP): partial response: 26 vs 9%, stable disease: 41 vs 55%, progressive disease: 33 vs 36%. Time to tumour progression (32 vs 27 weeks), and overall survival (60 vs 69 weeks) were not significantly different. Grade 4 adverse events were rare in both arms and treatment-associated mortality was not observed. In addition, there was no significant difference in terms of quality of life under therapy (EORTC).

CONCLUSION

TACO with DSM did not improve response or survival significantly compared to TACP in advanced non-resectable HCC.

Yersinia infection mimicking recurrence of gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. So far, surgical resection has been the only curative treatment, but new options became available with the application of imatinib (Glivec) as a specific molecular inhibitor. Even after complete resection, GISTs have a high rate of recurrence and disease-linked mortality. Here we report on the case of a clinically well 57-year-old woman who presented to us 3 years after resection of a GIST of the small intestine. Abdominal ultrasound and CT scan showed intestinal wall thickening in the area of anastomosis and mesenteric lymphadenopathy, suggesting a recurrence of the primary GIST. However, serological testing was positive for yersinia antibodies. Surgical exploration revealed an asymptomatic infection with Yersinia enterocolitica serotype O9, proven by positive culture and histology, which showed no evidence of malignancy. Prognostic variables for GIST as well as diagnostic measures and limitations for yersiniosis are discussed. In the end, only surgical exploration and histological analysis could establish the final diagnosis. In conclusion, GISTs have a high likelihood of recurrence even after complete resection, but an asymptomatic infection such as yersiniosis must be considered as a differential diagnosis to GIST recurrence.

[Intraarterial calcium stimulation (ASVS) for pancreatic insulinoma: comparison of preoperative localization procedures]

PURPOSE

Evaluation of clinical relevance of the arterial stimulation procedure with venous sampling (ASVS) in the preoperative localization of insulinoma.

METHODS

Thirteen patients with endogenous hyperinsulinism underwent preoperative transabdominal ultrasound (US), helical CT (CT), MRI, endoscopic ultrasound (EUS), and angiography (DSA) in conjunction with the ASVS-test for the detection of insulinoma. The results were compared with intraoperative findings, intraoperative ultrasound (IOUS) and histology.

RESULTS

Sensitivity was as follows: US 8%, MRI 27%, CT 46%, EUS 50%,DSA 69%,and ASVS 92%. Intraoperative palpation and IOUS yielded a sensitivity of 77%. In 3 patients the tumors were neither palpable nor detectable by IOUS, the mode of resection was based on preoperative diagnostics. The ASVS procedure as a functional test was superior to all other modalities for the preoperative tumor detection.

CONCLUSION

The ASVS was the most sensitive diagnostic modality. It should especially be considered in terms of health economical aspects when CT or MRI do not yield conclusive results.

Ureteric reconstruction

Although the ureter is functionally simply a tube to transport urine, ureteric surgery requires detailed anatomical knowledge and advanced surgical skills, because the ureter has a delicate blood supply. Therefore, the urological surgeon must have distinct strategies available to bridge ureteric defects of various sites and lengths. Furthermore, handling during and after surgery should be individualized to the patient's pre- and intraoperative situation. In this review, the indications for reconstruction of a specific ureteric defect, the required techniques and postoperative recommendations are discussed.

[Concepts for optimizing stent graft treatment of abdominal aortic aneurysms based on results of animal experiments]

PURPOSE

In the endoluminal therapy of abdominal aortic aneurysms, a short proximal aneurysm neck, endoleaks and the large size and stiffness of the introducer systems are responsible for many of the complications and sub-optimal outcomes. The purposes of the present review article is to to suggest strategies to minimize these complications based on the results of experimental studies in animals.

MATERIAL AND METHODS

After implanting various types of stents across the renal artery origins, the functional and morphological changes in the kidneys and renal vessels were studied by various authors. In order to prevent progressive widening of the proximal aneurysmal neck and graft dislocation, Sonesson et al. performed a laparoscopic banding around the proximal neck in pigs. To study the effects of endoleaks, Marty, Schurink and Pitton carried out pressure measurements in experimental aneurysms with and without endoleaks. Sakaguchi und Pavcnik developed the "Twin-tube endografts" (TTEG) and the "Bifurcated drum occluder endografts" (BDOEG) and tested them in dogs.

RESULTS

Up to 3 months after suprarenal stent placement, Chavan et al. detected no significant fall in the mean inulin clearance in sheep (140 +/- 46 ml/min before, 137 +/- 58 ml/min after). Nasim et al. and Malina et al. reported similar observations with respect to renal function. Suprarenal fixation may result in isolated thrombotic occlusions of the renal arteries and microinfarcts in the kidneys. Mean aortic diameters at the level of banding were significantly smaller in the animals with aortic banding as opposed to those in the control group without banding (8 mm vs 11 mm, p = 0.004). The banding caused a secure proximal fixation of the stent-graft. Persistent endoleaks resulted in significantly higher intraaneurysmal pressures. Although the TTEG and the BDOEG stent-grafts required smaller sheaths, occlusions were observed in 8% (TTEG) and 60% (BDOEG) of the graft limbs.

DISCUSSION

Supra-renal fixation of the stent-graft does not significantly affect renal function. Depending partly on the stent-graft-Design, isolated microinfarcts in the kidneys or thrombotic occlusions of the renal arteries may occur. A laparoscopic banding of the aorta at the proximal neck after graft implantation could prevent widening of the proximal neck and graft dislocation with the passage of time. To reduce the incidence of endoleaks, embolization of large branches, particularly those arising from aneurysms without mural thrombus is advisable. Due to the relatively high rate of occlusion of the graft limbs, the TTEG and the BDOEG stent-graft designs still require refinement. A rational application of the results of these animal experimental studies in clinical practice could markedly improve the long-term results of endoluminal stent grafting of abdominal aortic aneurysms.

[Hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber disease) and its manifestation in the liver]

M. Osler (Hereditary Hemorrhagic Telangiectasia, HHT) is an autosomal dominant inherited disease, with various vascular malformations. The genetic cause of this disease lies in different defects of transmembrane proteins (endoglin, activin receptor like-kinase 1) that can be defined as components of the receptor complex for transforming growth factor beta (TGF beta). Vascular malformations include the gastrointestinal tract and especially the liver. The location of mutations encoding hepatic involvement of M. Osler still remains unknown. These vascular malformations may lead to different shunts in the liver and can result to different complications like cardiac-insufficiency, portal hypertension and hepatic encephalopathy in adulthood. Color Doppler sonography is the method of choice for screening patients with M. Osler--suspected of having hepatic involvement. As in rare events conservative treatment of complications of hepatic involvement fail, embolization of the hepatic artery as minimal invasive therapy, surgical ligation of the A. hepatica and liver transplantation are possible treatment options. As there are only limited experiences with these therapeutic procedures patients with liver involvement should be treated at a center, where all therapy options are available.

Precise determination of aortic length in patients with aortic stent grafts: in vivo evaluation of a thinning algorithm applied to CT angiography data

The aim of this study was to develop a technique for precise determination of the aortic length using volumetric CT data for potential use prior to endovascular stent-graft placement. The study population consisted of 20 patients (38 measurements) with already performed endoluminal grafting. This allowed for in vivo evaluation of our technique. Its length according to the graft specifications served as a gold standard for our own measurements. The implemented graft length varied between 120 and 195 mm. Computed tomography angiography was performed with 3-mm slice collimation, 5-mm table feed and a reconstruction interval of 2 mm. Following semi-automatic segmentation of the aorta and its large side branches, the median centerline (skeleton) of the vessels was determined employing a modified three-dimensional thinning algorithm. The algorithm was validated by comparing the calculated length of the resulting skeleton with the specifications of the grafts. The calculated length was sufficiently precise despite the limiting reconstruction interval of 2 mm of our CT data which only permitted an assessment of stent length in 2-mm steps. The differences in the measured length and graft length were in the range between 0 and 8 mm (< 5%) with a mean fractional error of 2.46 +/- 2.37 mm. The use of an intelligent region growing algorithm capable of coping with variable arterial enhancement significantly reduced operator post-processing time. The average time necessary for segmentation was 7 min (range 3-10 min). Our algorithm provides a non-invasive method for objective and precise measurement of aortic length apparently even in tortuous vessels. It has the potential to replace angiography for aortic and iliac length measurements with calibrated catheters prior to endovascular intervention.

Role of the intra-arterial calcium stimulation test in the preoperative localization of insulinomas

The aim of this study was determination of the significance of the arterial stimulation test with venous sampling (ASVS) in the preoperative localization of insulinoma. Eleven patients with endogenous hyperinsulinism underwent preoperative transabdominal US, spiral computer tomography (spiral CT), MRI, endoscopic ultrasound (EUS) as well as angiography (DSA) combined with ASVS. The results were compared with intraoperative findings, intraoperative ultrasound (IOUS) and histopathology. There were no complications related to the ASVS test. In 11 patients the tumor could be localized with the various modalities as follows: US 1 of 11 (9%), MRI 3 of 10 (30%), spiral CT 4 of 11 (36%), EUS 5 of 10 (50%), DSA 8 of 11 (73%), and ASVS 10 of 11 (91%). In 2 patients the tumors were intraoperatively neither palpable nor detectable by IOUS, and consequently the intraoperative management was governed by information provided by DSA combined with the ASVS test. Ten patients had solitary benign insulinomas and 1 patient with multiple endocrine neoplasia I had two tumors adjacent to each other in the pancreatic tail. Arterial stimulation test with venous sampling was the most sensitive preoperative test for regionalizing the insulinoma in our set of patients. It can be performed safely in the course of a regular DSA examination and may affect intra-operative management in patients in whom the tumors are not detectable by palpation or IOUS.