Beyond image defined risk factors (IDRFs): a delphi survey highlighting definition of the surgical complexity index (SCI) in neuroblastoma

PURPOSE

Preoperative evaluation of Image Defined Risk Factors (IDRFs) in neuroblastoma (NB) is crucial for determining suitability for upfront resection or tumor biopsy. IDRFs do not all carry the same weighting in predicting tumor complexity and surgical risk. In this study we aimed to assess and categorize a surgical complexity (Surgical Complexity Index, SCI) in NB resection.

METHODS

A panel of 15 surgeons was involved in an electronic Delphi consensus survey to identify and score a set of shared items predictive and/or indicative of surgical complexity, including the number of preoperative IDRFs. A shared agreement included the achievement of at least 75% consensus focused on a single or two close risk categories.

RESULTS

After 3 Delphi rounds, agreement was established on 25/27 items (92.6%). A severity score was established for each item ranging from 0 to 3 with an overall SCI range varying from a minimum score of zero to a maximum score of 29 points for any given patient.

CONCLUSIONS

A consensus on a SCI to stratify the risks related to neuroblastoma tumor resection was established by the panel experts. This index will now be deployed to critically assign a better severity score to IDRFs involved in NB surgery.

Selective use of Peptide Receptor Radionuclide Therapy following comparative imaging of Ga-68 DOTATATE PET/CT against I-131 MIBG scintigraphy in a small Asian cohort of Adult Neuroblastoma

Adult neuroblastoma (AN) is rare with an extremely poor prognosis. No standard therapy exists for this entity and treatment options are limited in recurrent or refractory disease. ¹³¹I-MIBG has been used in combination with myeloablative therapy before autologous bone marrow transplantation or in a salvage therapy setting. However, myelotoxicity is a dose-limiting factor in heavily pre-treated patients and response is not always sustained. Somatostatin receptor scintigraphy and theranostics with radiolabelled somatostatin receptor analogues are becoming more commonplace with the recognition of these receptors in over 90% of neuroblastoma cells. We describe three AN patients assessed for somatostatin receptor status and the novel use of ¹⁷⁷Lu-based peptide recep-tor radionuclide therapy (PRRT) in two of them and a literature review.

Differential impacts of carp and salmon pituitary extracts on induced oogenesis, egg quality, molecular ontogeny and embryonic developmental competence in European eel

Low egg quality and embryonic survival are critical challenges in aquaculture, where assisted reproduction procedures and other factors may impact egg quality. This includes European eel (Anguilla anguilla), where pituitary extract from carp (CPE) or salmon (SPE) is applied to override a dopaminergic inhibition of the neuroendocrine system, preventing gonadotropin secretion and gonadal development. The present study used either CPE or SPE to induce vitellogenesis in female European eel and compared impacts on egg quality and offspring developmental competence with emphasis on the maternal-to-zygotic transition (MZT). Females treated with SPE produced significantly higher proportions of floating eggs with fewer cleavage abnormalities and higher embryonic survival. These findings related successful embryogenesis to higher abundance of mRNA transcripts of genes involved in cell adhesion, activation of MZT, and immune response (dcbld1, epcam, oct4, igm) throughout embryonic development. The abundance of mRNA transcripts of cldnd, foxr1, cea, ccna1, ccnb1, ccnb2, zar1, oct4, and npm2 was relatively stable during the first eight hours, followed by a drop during MZT and low levels thereafter, indicating transfer and subsequent clearance of maternal mRNA. mRNA abundance of zar1, epcam, and dicer1 was associated with cleavage abnormalities, while mRNA abundance of zar1, sox2, foxr1, cldnd, phb2, neurod4, and neurog1 (before MZT) was associated with subsequent embryonic survival. In a second pattern, low initial mRNA abundance with an increase during MZT and higher levels persisting thereafter indicating the activation of zygotic transcription. mRNA abundance of ccna1, npm2, oct4, neurod4, and neurog1 during later embryonic development was associated with hatch success. A deviating pattern was observed for dcbld1, which mRNA levels followed the maternal-effect gene pattern but only for embryos from SPE treated females. Together, the differences in offspring production and performance reported in this study show that PE composition impacts egg quality and embryogenesis and in particular, the transition from initial maternal transcripts to zygotic transcription.

Pediatric Obsessive-Compulsive Disorder Exacerbation and Obstructive Hydrocephalus: A Case Report

We present the case of an 11 year-old boy with a previous history of obsessive-compulsive disorder (OCD), who experienced a dramatic and acute worsening of OCD symptoms in temporal association with obstructive hydrocephalus secondary to a tectal low-grade glioma. Management and resolution of the hydrocephalus was temporally associated with an improvement in his OCD compulsion symptoms. The present case does not establish proof of cause and effect, but highlights potential multifactorial influences on OCD onset and clinical course. Cortico-striatal-thalamic-cortical pathways, physically distorted by hydrocephalus in this case, have long been implicated in OCD etiology. Clinical implications include the importance of conducting an appropriate neurologic work-up to rule out biological causes for acute and dramatic OCD exacerbations with neurologic signs, even in the context of preexisting OCD. Given that neurologic lesions may exist in the absence of typical signs and symptoms, that they may further disrupt OCD circuitry, and that treatment may lead to resolution of associated psychiatric symptoms, it is important to remain cognizant of these differential diagnoses.

[What do medical students think of family medicine? Results of an online cross-sectional study in the federal state of Baden-Wuerttemberg]

BACKGROUND

In the context of physician shortages, critical factors influencing career choice need to be better understood. The aim of this study was to explore experiences students have had with family medicine in order to develop additional strategies for recruiting family medicine trainees.

METHODS

Students from the five medical faculties in the federal state of Baden-Wuerttemberg were invited to participate in an online-survey via email. A purpose-built questionnaire was used. In addition to descriptive statistics, analysis included linear partial correlations controlled for age, gender, and semester, which were calculated between the variable "I believe family medicine is an attractive job" and the 31 variables of the survey. Linear regression was used to analyze the influence of experiences with family medicine and statements about family medicine to the perception of family medicine as an attractive specialty.

RESULTS

1299 students participated in the survey. About half of the participants (49.7 %) considered working as a primary care physician to be attractive or partly attractive. 49.6 % of students reported positive experiences with family medicine as a patient and 33.1 % as a family member. 24.3 % reported positive experiences during the compulsory 1-2 weeks general practice internship and 18.1 % during a four weeks elective placement. For 302 participants (23.3 %), family medicine is presented positively in the media. 178 (13.7 %) consider family medicine to have high importance in both undergraduate and postgraduate education. Positive influences on judging attractiveness of family medicine were: own experience with family medicine as a clinical elective (rpart= + 0.450), own experience with family medicine as a patient (rpart= + 0.218), perception that family medicine offers a diversified working day (rpart= + 0.259), and perception that family medicine offers a good salary (rpart= + 0.242).

CONCLUSION

To enable students during undergraduate studies to have practical experience with family medicine seems to be an important influence on judging family medicine attractive.

Delayed diagnosis of pseudoaneurysm formation in a patient with diaphyseal aclasis

A 15 year old boy, with known diaphyseal aclasis, presented with a swollen left leg. The diagnosis of popliteal pseudoaneurysm, a known and well understood vascular complication, was delayed due to presentation suggestive of a chondrosarcoma. In this age group, sarcomatous change is more common and a potentially sinister complication of diaphyseal aclasis. Following a sarcoma MDT referral, the correct diagnosis was confirmed by ultrasound and CT angiogram. This case identifies one of the largest, non-ruptured popliteal pseudoaneurysms reported and illustrates an unusual complication of a rare orthopaedic genetic condition, which is potentially limb threatening.

Swelling in the upper arm: the presentation and management of an isolated brachial artery aneurysm

True aneurysms of the brachial artery are uncommon. We describe the presentation and surgical management of an isolated, brachial artery aneurysm in a 64-year-old woman. Excision of the aneurysm and long saphenous venous interposition grafting was performed with no postoperative complications and histology demonstrated true aneurysmal degeneration.

[Development, factor-analytical control and psychometric evaluation of a questionnaire on specialty choices among medical students]

AIM OF THE STUDY

A questionnaire was developed and validated which assesses factors influencing career choices of medical students and their perception of possibilities in general practice.

METHODS

The first questionnaire version, which was developed based on a systematic literature review, was checked for comprehensibility and redundancy using concurrent think aloud. The revised version was filled out by a pilot sample of medical students and the factor structure was assessed using principal component analysis (PCA). The final version was filled out in an online survey by medical students of all 5 Medical Faculties in the federal state of Baden-Wuerttemberg. The factor structure was validated with a confirmatory factor analysis (CFA). Reliability was assessed as internal consistency using Cronbach's α.

RESULTS

The questionnaire comprises 2 parts: ratings of (A) the individual importance and of (B) the possibilities in general practice on 5-point scales. The first version comprising 118 items was shortened to 63 items after conducting interviews using concurrent think aloud. A further 3 items giving no information were removed after piloting the questionnaire on 179 students. The 27 items of part A were structured in 7 factors (PCA): image, personal ambition, patient orientation, work-life balance, future perspectives, job-related ambition, and variety in job. This structure had a critical fit in the CFA applied to the final version filled out by 1 299 students. Internal consistency of the factors was satisfactory to very good (Cronbach's α=0.55-0.81).

CONCLUSION

The questionnaire showed good psychometric properties. Further, not assessed factors influence career choice resulting in unexplained variance in our dataset and the critical fit of the model.

[Aspirations of medical students: "planning for a secure career" - results of an online-survey among students at five medical schools in Germany]

BACKGROUND

In times of shortage of doctors, expectations and interests of the future generation of doctors towards their career aspiration is of major importance. The aim of this study was to analyze expectations of medical students at the five medical schools in the State of Baden-Wuerttemberg (Germany) concerning their career choice and factors influencing it.

METHODS

Between January and February 2010, 1299 medical students (out of 12 062 medical students at the five medical schools) participated in an online-survey. In addition to sociodemographic items, career choice and aspects of planning reliability were raised.

RESULTS

Three quarters of the students assign a medical profession for their future occupation. There is a dominance of internal medicine (n = 152), gynaecology (n = 127), paediatrics (n = 125), surgery (n = 115), anaesthesiology (n = 101), and family medicine (n = 88). The time point of decision varies between the different undergraduate years of medical school and specialty. Students at the beginning of their studies seem to be interested mostly in surgery. During medical school the interests towards internal medicine grows. Regarding planning dependability important aspects for medical students were to work in a job that has a future (61.2 % fully agree), to have a safe job (57.7 %), and to have a safe income (57.1 %). Less important seems to be to have good opportunity to earn money (29.6 %).

CONCLUSIONS

Interest in a certain specialty changes markedly at during medical school. Factors such as economical guarantee, good future prospects and also the studies itself have an essential impact for students on choosing a specific career. Strategies to face physicians' shortage in different specialties need to be close to the needs and expectations of future physicians. This is not only valid for the undergraduate time period but also for the work circumstances of their future.

Vertebral fracture in a pilot during centrifuge training: finding of osteopenia

We report on a case of an F-16 pilot who suffered a compression fracture of the L5 vertebral body during centrifuge training. The pilot sustained the injury during a rapid onset to 6 G run. He was subsequently diagnosed to have osteopenia with a bone mineral density T-score of -1.95. This report discusses the medical and operational management of the pilot with this rare condition. The pilot has since returned to flying duties, albeit in a transportplatform.

[Foundations of shared decision making and examples of its application in rehabilitation]

Enhanced patient participation in health care is demanded due to better knowledge of patients about diseases and their treatment, due to more treatment strategies in the course of scientific progress, due to ethical and legal considerations, and due to study results. With shared decision-making (SDM) a method was defined for the medical interview to involve patients in treatment decisions. Process steps for orientation are available for the procedure of the medical encounter. Transfer of shared decision-making into health care can be realized through three strategies, i. e., by physician training to enhance physicians' competencies in medical encounter, by decision aids for better information and preparation for decision making, and by patient education. For examination and fostering of SDM in German health care the German Ministry of Health initiated a research consortium in the years 2001 to 2007 called "Patient as a partner in medical decision making". In an additional research consortium of the German Ministry of Education and Research, the German Pension Insurance scheme as well as the associations of statutory and private health insurance, various projects for health services research on the subject of "Chronic Diseases and Patient Orientation" will be funded starting in 2008. This initiative with a focus on rehabilitation will foster studies about need-specific patient information, training programmes for chronically ill patients, and about the organisation of a more participative structure of health care delivery.

Achieving blood pressure goals globally: five core actions for health-care professionals. A worldwide call to action

The prevalence of hypertension continues to rise across the world, and most patients who receive medical intervention are not adequately treated to goal. A Working Group including representatives of nine international health-care organizations was convened to review the barriers to more effective blood pressure control and propose actions to address them. The group concluded that tackling the global challenge of hypertension will require partnerships among multiple constituencies, including patients, health-care professionals, industry, media, health-care educators, health planners and governments. Additionally, health-care professionals will need to act locally with renewed impetus to improve blood pressure goal rates. The Working Group identified five core actions, which should be rigorously implemented by practitioners and targeted by health systems throughout the world: (1) detect and prevent high blood pressure; (2) assess total cardiovascular risk; (3) form an active partnership with the patient; (4) treat hypertension to goal and (5) create a supportive environment. These actions should be pursued with vigour in accordance with current clinical guidelines, with the details of implementation adapted to the economic and cultural setting.

[Effects of a shared decision making model in psychiatric and neurologic practice]

Involving patients in medical decisions is increasingly being advocated in medical fields other than psychiatry and neurology. A model of shared decision making might prove to be an ideal way of bridging the gap between patient-centred and evidence-based medicine. This report provides a survey of this shared decision making model and a discussion of its implications in the fields of mental health and neurology.

Development and first validation of the shared decision-making questionnaire (SDM-Q)

OBJECTIVE

Due to a lack of valid German instruments measuring shared decision-making (SDM), a theory-driven questionnaire (SDM-Q) to measure the process of SDM was developed and validated.

METHODS

As a theoretical basis steps of the SDM process were defined in an expert panel. Item formulation was then conducted according to the Delphi method. For the first validation on a mixed sample Rasch analysis was used to eliminate items not fitting the construct thus receiving a unidimensional scale.

RESULTS

After eliminating 4 items the remaining 11 form a unidimensional scale with an acceptable reliability for person measures (0.77) and very good reliability for item difficulties (0.95). Analysis of subgroups revealed a different use of items in different conditions. Furthermore the scale showed high ceiling effects.

CONCLUSION

A new theory-driven instrument to measure the process of SDM has been developed and validated by use of a rigorous method revealing first promising results. Yet the ceiling effects require the addition of more discriminating items, and the different use of items in different conditions demands an in depth analysis.

PRACTICE IMPLICATIONS

While the concept of SDM is constantly receiving more attention in medical practice, its valid and reliable measurement remains challenging.

Spontaneously arising superficial temporal artery aneurysms: a report of two cases and review of the literature

The majority of superficial temporal artery (STA) aneurysms are due to trauma and are, in reality, false aneurysms. However, true STA aneurysms are extremely rare. Here, we present two cases of spontaneous superficial temporal artery aneurysms arising without any previous history of trauma.

A New Approach: Regional Nerve Blockade for Angioplasty of the Lower Limb

PURPOSE

An audit study investigated the pilot use of regional nerve block analgesia (as an alternative to sedative/opiate, general or central neuraxial anesthesia) performed by radiologists with the assistance of imaging techniques during complex prolonged angiography.

METHODS

Radiologists were trained by anesthetic consultants to administer and use lower limb peripheral nerve block for difficult prolonged angioplasty procedures for patients with severe lower limb rest pain who were unable to lie in the supine position. In a pilot study 25 patients with limb-threatening ischemia received sciatic and femoral nerve blockade for angioplasty. The technique was developed and perfected in 12 patients and in a subsequent 13 patients the details of the angiography procedures, peripheral anesthesia, supplementary analgesia, complications, and pain assessment scores were recorded. Pain scores were also recorded in 11 patients prior to epidural/spinal anesthesia for critical ischemic leg angioplasty.

RESULTS

All patients with peripheral nerve blockade experienced a reduction in their ischemic rest pain to a level that permitted angioplasty techniques to be performed without spinal, epidural or general analgesia. In patients undergoing complex angioplasty intervention, the mean pain score by visual analogue scale was 3.7, out of a maximum score of 10.

CONCLUSIONS

The successful use of peripheral nerve blocks was safe and effective as an alternative to sedative/opiate, epidural or general anesthesia in patients undergoing complex angiography and has optimized the use of radiological and anesthetic department resources. This has permitted the frequent radiological treatment of patients with limb-threatening ischemia and reduced delays caused by the difficulty in enlisting the help of anesthetists, often at short notice, from the busy operating lists.

[Development and validation of assessment instruments for shared decision making]

The German Ministry for Health and Social Security is funding ten projects to introduce shared decision making into clinical practice. The medical problems the projects are focussing on were chosen from among various diseases (e. g. depression, multiple sclerosis, cancer). The ten projects achieved consensus on a core set of instruments for the measurement of process and outcome of the shared decision making. Instruments developed in German-speaking countries are currently not available. Thus, linguistic and cultural validation had to be performed for the core set instruments. The results of the data analysis as well as patient interviews demonstrate the need for improving these instruments. Therefore, the members of the methodological working group concentrated on the integration of these results in a new instrument. In a first step the construct of "shared decision making" was defined, followed by a definition of the process elements characterising shared decision making. Thereafter, items were developed on the basis of the process elements. The new instrument will now be validated for different diseases.

Entwicklung und Evaluation eines Fortbildungsprogramms zur Partizipativen Entscheidungsfindung f�r die haus�rztliche Versorgung depressiver Patienten

Patient surveys show that many patients want broad information about their disease and treatment. Often they are interested to participate in the process of medical decision making, which could be realised with the concept of shared decision making where patient's values and needs are considered to the same extent as the treatment recommendations of evidence-based medicine. In depression care, it has been demonstrated so far that the active involvement of patients contributes to higher motivation for treatment. For enhancing patient's acceptance and motivation to avail themselves of medical treatment, a training program for general practitioners was developed and evaluated. It was the aim of the training to involve depressive patients in medical decision making. The training consists of depression-specific components (e. g. diagnosis, patient information, therapy) and general components (communication and shared decision making). The training was carried out in five sessions within a 6-month period (May to October 2003) embracing 20 h of training. Participants were 20 general practitioners in Southwest Germany. Physician's satisfaction with the training program is high. Especially in the fields of diagnosis and shared decision making the physicians clearly benefited. Transfer of shared decision making into daily routine was assessed as possible by the large majority of the trainees. Application of the training concept to other diseases and evaluation on the basis of daily routine is recommended. The training effects on medical care are presently being assessed in a randomised controlled trial.

Fr�h- und Basisintervention bei Patienten mit schizophrenen St�rungen

THEORETICAL BACKGROUND

Of all outpatients with a diagnosis of schizophrenia, 30-40% refuse a psychiatrist's care. For this group of patients the general practitioner holds a key position for such different tasks as detection of prodromal schizophrenia or early warning signs of relapse and identification of risk variables for deteriorating outcome, gatekeeping (referral to specialists or other services), integration, and counseling of key relatives. Fifty percent of GPs are interested in disease-specific medical education programs.

STUDY DESIGN AND METHODS

A control trial examined the changes that participating GPs intended to make in three main topics of the curriculum: (1) changing attitudes (pessimistic outcome expectation, low self-esteem), (2) enhancement of detection skills (prodromal schizophrenia, early warning signs of relapse, and risk factors for poor social and vocational integration), and (3) enhancement of management skills (dosing schemes, motivational interviewing).

RESULTS

In the assessment 2 weeks after the training session, we found significant changes in favor of the trained group in detection and management skills and also improved self-confidence of GPs.

CONCLUSIONS

Problem-oriented and case-based learning strategies should be preferred to lectures in training programs for psychiatric skills in primary care.

Pharmacokinetic model of iodine-131-G250 antibody in renal cell carcinoma patients

A model that describes the pharmacokinetic distribution of 131I-labeled G250 antibody is developed.

METHODS

Previously collected pharmacokinetic data from a Phase I-II study of 131I-G250 murine antibody against renal cell carcinoma were used to develop a mathematical model describing antibody clearance from serum and the whole body. Survey meter measurements, obtained while the patient was under radiation precautions, and imaging data, obtained at later times, were combined to evaluate whole-body clearance kinetics over an extended period.

RESULTS

A linear two-compartment model was found to provide good fits to the data. The antibody was injected into Compartment 1, the initial distribution volume (Vd) of the antibody, which included serum. The antibody exchanged with the rest of the body, Compartment 2, and was eventually excreted. Data from 13 of the 16 patients fit the model with unique parameters; the maximum, median and minimum values for model-derived Vd were 6.3, 3.7 and 2.11, respectively. The maximum, median and minimum values for the excretion rate were 8 x 10(-2), 2.4 x 10(-2) and 1.3 x 10(-2) hr(-1), respectively. Parameter sensitivity analysis showed that a change in the transfer rate constant from serum to the rest of the body had the greatest effect on serum cumulative activity and that the rate constant for excretion had the greatest effect on whole-body cumulative activity.

CONCLUSION

A linear two-compartment model was adequate in describing the serum and whole-body kinetics of G250 antibody distribution. The median initial distribution volume predicted by the model was consistent with the nominal value of 3.81. A wide variability in fitted parameters was observed among patients, reflecting the differences in individual patient clearance and exchange kinetics of G250 antibody. By selecting median parameter values, such a model may be used to evaluate and design prolonged multiple administration radioimmunotherapy protocols.

Hypercoagulable states in patients with leg ischaemia

Hypercoagulable states are found in up to 10 per cent of patients with a history of unexplained venous thrombosis. To investigate the prevalence in arterial thrombosis, thrombophilia screening was performed on 124 patients who had previously undergone lower-limb revascularization, 45 claudicants and 27 controls. Of the patients who had undergone revascularization 40 per cent had a hypercoagulation abnormality (low levels of protein C, protein S and antithrombin III or presence of the lupus anticoagulant) in comparison with 27 per cent of claudicants and 11 per cent of controls (P < 0.01). Furthermore, patients who had suffered reocclusion after revascularization were significantly more likely to have a hypercoagulation abnormality than those who had not (P < 0.05), even if the occlusion had occurred more than 6 months previously. Lupus anticoagulant was the abnormality most frequently detected and, like low protein C levels, was found only in patients with peripheral vascular disease. It appears that hypercoagulable states are common in patients with arterial disease and may predispose to failure of revascularization.

Solitary benign papilloma (papillary adenoma) of the cystic duct: a rare cause of biliary colic

Benign tumours of the extrahepatic bile ducts are rare, mostly occurring in the common bile duct and hepatic ducts. Solitary papillomas occur mainly in the gallbladder or at the ampulla of Vater. Tumours of the cystic duct are extremely rare, and we are unaware of any reports of solitary papilloma of the cystic duct. Such a case in a 72-year-old woman is presented.

Detection of circulating cerebral emboli using Doppler ultrasound in a sheep model

We describe a validation study of a new technique for detecting circulating pathological cerebral emboli. Theoretically one would expect solid emboli to be detectable as high intensity signals on the Doppler waveform, and such signals have been reported in humans with potential embolic sources. Pathological cerebral emboli (thrombi, platelet aggregates and atheroma) were introduced into the proximal carotid artery of an in vivo sheep model, and their passage detected in the cerebral circulation using Doppler ultrasound. All of 74 emboli, with a maximum dimension as small as 0.24 mm, were detected as short duration high intensity signals. Smaller pathological emboli could not be made but glass microspheres as small as 5-20 micron resulted in high intensity signals. A significant positive correlation was found between embolus size and relative intensity increase of the embolic signal. A significant positive correlation was also found between embolus size and duration of embolic signal. This study demonstrates that detection of circulating cerebral emboli is possible in vivo. This technique may allow selection of patients at particularly high risk of cerebral embolisation so that they can be given specific prophylactic treatment. Analysis of the Doppler signal may give information on the size of the embolus, although using current signal analysis it is impossible to distinguish between the signals produced by say a larger platelet embolus or a smaller thrombus embolus.

Accuracy of intraoperative staging in colorectal cancer

In 216 patients with colorectal adenocarcinoma 'operative' and 'final' staging using Duke's classification were compared. The overall 'accuracy' of operative staging was 66% with 17% of tumours understaged and 17% overstaged. The major error was found in nodal staging. If selective peroperative adjuvant therapy is to be considered, efforts should be directed to improve operative nodal staging. Any recommendation for adjuvant perioperative chemotherapy based on operative staging alone will result in a significant number of patients having unnecessary treatment.

Simplified technique for peritoneal dissection during laparoscopic hernia repair

The use of a small rod (5-mm diameter, 20-cm length, code no. BN320, Aesculap Ltd., Sheffield, England) inserted extraperitoneally has been a useful tool in aiding peritoneal dissection during laparoscopic hernia repair. Experience gained in 100 such repairs using this instrument has helped to reduce the operating time in most instances.

Computerized detection of cerebral emboli and discrimination from artifact using Doppler ultrasound

BACKGROUND AND PURPOSE

Transcranial Doppler ultrasound can detect circulating cerebral emboli. Monitoring of patients with potential embolic sources may allow identification of high-risk patients who can then be selected for prophylactic treatment. However, practical patient monitoring will require automated programs that can detect emboli and differentiate them from artifact.

METHODS

A new off-line algorithm for the detection of emboli, which detects the characteristic relative power increase occurring with an embolus, was evaluated in both an animal model and in patients. (1) In a sheep model, solid embolic materials (thrombus, platelet aggregates, and atheroma) were introduced into the proximal carotid artery while the distal carotid artery or a major branch was insonated. The signals resulting from 77 emboli (mean size, 1.77 mm) were studied and compared with the Doppler signals resulting from artifact. (2) In patients, 100 embolic signals occurring in three patients were analyzed and compared with signals associated with artifact in the same patients.

RESULTS

(1) In the sheep model, emboli resulted in a short-duration, high-intensity signal, but intensity increase alone did not distinguish between emboli and artifact. In contrast, the algorithm discriminated embolus from artifact with a sensitivity of 98.7% and a specificity of 98.0%. (2) In patient studies, embolic signals were differentiated from artifact with a sensitivity of 97.2% and a specificity of 97.0% by the algorithm.

CONCLUSIONS

Using such an algorithm, detection of cerebral emboli and discrimination from artifact are possible with a high sensitivity and specificity. Incorporation of such an algorithm into an on-line system should make prolonged patient monitoring practical.

Microscopic air embolism during cerebral angiography and strategies for its avoidance

Cerebral angiography is associated with a risk of neurological complications and air embolism may contribute towards this risk. To test this hypothesis, transcranial doppler ultrasonography was used to monitor the presence of air emboli in the middle cerebral arteries of 7 patients undergoing cerebral angiography. Doppler signals consistent with numerous air emboli were noted during each injection of radiographic contrast. This phenomenon was studied further in sheep. Radiographic contrast medium was injected into the carotid artery while a major carotid branch was insonated transorbitally. Embolic signals similar to those seen in patients were noted. Air was introduced at two points. First, at the time of drawing up the contrast into the syringe, especially with more viscous media. Standing the media before injection resulted in a highly significant reduction of air embolism, reducing the total mean duration of emboli from 1.32 (SD 0.60) s after immediate injection to 0.04 (0.05) s after ten minutes standing for iohexol 340 mg/mL (p < 0.001). Second, air was introduced at the time of injection, possibly by the formation of cavitation bubbles under pressure. This occurred most prominently with the less viscous contrast media and with saline, and was significantly reduced by slow injection (mean duration of emboli for saline 2.85 [2.43] s with fast injection compared with 0.32 [0.37] s with slow injection, p = 0.004). Air embolism may contribute towards neurological dysfunction after angiography. Measures should be taken to reduce this by allowing contrast media to stand prior to injection, and by flushing catheters with saline injected slowly.

PTFE bypass grafting to isolated popliteal segments in critical limb ischaemia

Although the quality of the distal run-off has been considered as an important factor affecting the success of bypass grafting, reasonable results have nevertheless been reported for bypass grafts to a popliteal artery with no direct communication with the tibial or peroneal vessels (isolated popliteal segment, IPS). The use of autogenous vein has produced the best results in this situation with most authors finding polytetrafluoroethylene (PTFE) less satisfactory. Improved results have nevertheless been shown for femoropopliteal and femorotibial PTFE grafts by the incorporation of vein patches into the anastomoses. In this paper, the influence of this technique on the patency of PTFE grafts to IPS is evaluated. Thirty-three PTFE grafts to an IPS and 67 to the below knee (BK) popliteal artery with one or more run-off vessels were studied. All IPS grafts were carried out for limb salvage and in the BK popliteal group, 46 (69%) were for limb salvage and 21 (31%) were for severe claudication. Groups were matched in terms of age, smoking history and prevalence of diabetes mellitus. Cumulative patency rates of 84% at 1 year and 76% at 3 years were achieved in the IPS group compared to 90 and 81% for the BK popliteal group with one or more run-off vessels. Using the Taylor patch technique, comparable 3 year patency rates can be expected for PTFE grafts to IPSs and to BK popliteal arteries with patient tibial or peroneal run-off.

Infrapopliteal angioplasty for limb salvage

Fourteen infrapopliteal angioplasties were performed in 13 patients with critical limb ischaemia. Clinical indications were rest pain, ulceration, gangrene or a critically ischaemic limb from a graft occlusion secondary to an infrapopliteal lesion. The average ankle-brachial ratio was 0.22 in non-diabetics. Technical success was achieved in all lesions with an average increase of Doppler ratios of 0.5. Of the 13 patients, 11 (85%) showed early clinical improvement (with average length of follow-up of 8 months, range 1-18 months). With the introduction of smaller lower profile catheters, hydrophilic and steerable wires and the advent of digital subtraction angiography, infrapopliteal angioplasty can now be performed successfully and with few complications. The presence of spasm should be aggressively treated with intra-arterial nitroglycerin or verapamil.

Comparative tissue distribution of 125I- and U-14C-labeled recombinant human interleukin-2 in the rat

The distribution of recombinant human interleukin-2 (rhIL-2) after intravenous administration of 125I- or U-14C-labeled rhIL-2 is reported in the major organs of the rat. Five minutes after the administration of U-14C-labeled rhIL-2, the radioactivity had been rapidly cleared from the plasma, while 38% of the dose was found in the kidneys, confirming that the major site of clearance for rhIL-2 is the kidney. After 1 h, a large fraction of the radioactivity had disappeared from the kidney and was found in the carcass. When the same experiments were carried out with 125I-labeled rhIL-2, comparable distribution results were obtained: Preferential accumulation of 125I radioactivity (37.4%) was found in the kidney at 5 min after iv administration of 125I-labeled rhIL-2. One hour after dosing 125I label was predominantly present in the carcass (46%) and skin (15%). Similar percentages of the dose of 125I or 14C radioactivity were present in other organs or tissues. The present study indicates a similar distribution of the radiolabel in selected tissue and organs regardless of whether 14C or 125I was employed.

Improved technique for polytetrafluoroethylene bypass grafting: long-term results using anastomotic vein patches

Results of peripheral arterial bypass using polytetrafluoroethylene grafts have remained poor in comparison with those using saphenous vein grafts, particularly for anastomoses to tibial and peroneal vessels. A simple modification to the conventional operative technique, involving the incorporation of a vein patch into the distal anastomosis, has enabled considerable improvement. Five-year patency rates of 71 per cent for popliteal and 54 per cent for infrapopliteal grafts have been achieved in a series of 256 patients operated on between 1982 and 1989.

Anatomical repair of large incisional hernias

We present a method of repair for large incisional hernias using lateral relieving incisions of the anterior rectus sheath. This is a modification of the methods previously described by Young (1), Hunter (2) and Maguire and Young (3). There were no recurrences in the 13 patients reviewed. Other methods of repair for large incisional hernias are discussed.

Use of a breast template: an aid for orientation of breast biopsy specimens

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Evisceration and other complications of abdominal drains

Drainage following major abdominal surgery remains controversial. A case of small bowel evisceration through a Wallis drain site after an abdomino-perineal excision of rectum is reported as a complication of abdominal drainage.