Through the orbit and beyond: Current state and future perspectives in endoscopic orbital surgery on behalf of the EANS frontiers committee in orbital tumors and the EANS skull base section

Introduction

Orbital surgery has always been disputed among specialists, mainly neurosurgeons, otorhinolaryngologists, maxillofacial surgeons and ophthalmologists. The orbit is a borderland between intra- and extracranial compartments; Krönlein's lateral orbitotomy and the orbitozygomatic infratemporal approach are the historical milestones of modern orbital-cranial surgery.

Research question

Since its first implementation, endoscopy has significantly impacted neurosurgery, changing perspectives and approaches to the skull base. Since its first application in 2009, transorbital endoscopic surgery opened the way for new surgical scenario, previously feasible only with extensive tissue dissection.

Material and methods

A PRISMA based literature search was performed to select the most relevant papers on the topic.

Results

Here, we provide a narrative review on the current state and future trends in endoscopic orbital surgery.

Discussion and conclusion

This manuscript is a joint effort of the EANS frontiers committee in orbital tumors and the EANS skull base section.

[Use of neurodevelopmental disorder screening tool in primary care : A multicenter observational study]

INTRODUCTION

Neurodevelopmental disorders (NDD) affect 5 to 15% of the population. Improved management largely depends on early detection in primary care. A screening tool was developed by an expert consensus and its use has been recommended since 2019. This tool has never been evaluated to date. The aim of this study was to investigate the prevalence and factors associated with the identification of neurodevelopmental disorders in primary care in children aged 6 months to 5 years.

METHOD

This work is a multicentric observational study carried out in general practice in two regions of France: Île-de-France and Auvergne-Rhône-Alpes. A multivariate analysis was performed to identify the factors associated with the presence of abnormal signs on the grid.

RESULTS

Five hundred and sixty-four (564) children aged 6 months to 4 years were included. The prevalence of children identified on the grid was 3.9%. The factors associated with the neurodevelopmental disorders identified in multivariate analysis were: low socio-professional status of the mother, male gender and parental concern about the child's neurodevelopment. Factors associated with identifying a developmental trajectory gap were male gender (OR = 2.10 (1.22-3.62)) and low socio-professional status of the mother (OR = 2.23 [1.05-4.70]).

CONCLUSION

This original work allowed us to carry out first-line testing of a tool for the identification of NDD in primary care and to evaluate the prevalence of identification of these disorders. A complementary cohort study will be necessary to evaluate the sensitivity and specificity of this identification tool.

Lateral Approach to the Cervical Spine to Manage Degenerative Cervical Myelopathy and Radiculopathy

BACKGROUND

The cervical lateral approach can enlarge the spinal canal and foramen to achieve an effective neural decompression without needing spine stabilization. For this review, the authors' main objective was to illustrate the rationale, advantages, disadvantages, complications, and pitfalls of this technique, highlighting also areas for future development.

MATERIALS AND METHODS

A Medline via PubMed database search was carried out by using both keywords, namely "cervical oblique corpectomy," "multilevel oblique corpectomy and foraminotomy," and "lateral vertebrectomy," and Medical Subject Headings (MeSH) terms from 1 January 1991, up to 31 December 2021.

RESULTS

The analyzed articles suggested that the use of such a technique has declined over time; only 29 clinical studies met all the inclusion criteria and were retained for data analysis, including 1200 patients undergoing such an approach for the management of degenerative cervical myelopathies (DCMs) or of radiculopathies. The main etiopathogeneses were cervical stenosis, degenerative disk disease, or a mix of them-78% of which had a favorable outcome; the most frequent complications were transient and permanent Horner syndrome in 13.6% and 9.2% of cases, respectively. Long-term stability was reported in 97% of patients.

CONCLUSION

Multilevel cervical oblique vertebrectomy and/or lateral foraminotomy allow wide neural structure decompression and optimal stability given that the physiological spinal motion is preserved.

P07.02.B Neuro-oncological augmented reality planning (NOA-p)

Background

When preparing for the resection of an intracranial lesion, neuronavigation with a tracked pointer is most often used to determine lesion borders and the optimal approach. This can sometimes prove challenging, especially for deep-seated lesions. Augmented Reality (AR), directly displaying the lesion on the patient’s skin, can simplify and improve this step.

Material and Methods

We developed a system for inside-out infrared tracking that does not require an external tracking camera or external computer and allows for heads-up displaying an AR scene on the Microsoft HoloLens II. Twenty patients planned for the resection of an intracerebral lesion were included in our study. After patient registration, the lesion outlines were marked on the patient’s skin by different participants, consecutively using the Brainlab neuronavigation system and the HoloLens. Each registration on both systems provided a registration transform that was compared for accuracy and consistency. The performance of the participants was measured in terms of duration and accuracy and compared to expert registration and delineation.

Results

Both registration and delineation were significantly faster with AR (p=0.02 and p<0.001, respectively, and p<0.001 for the total duration), taking 79.23±17.48 and 39.58±39.10 seconds while neuronavigation required 96.61±24.54 and 90.80±44.09 seconds. AR had a registration offset of 3.3mm and 3.4°, and was more consistent compared to neuronavigation. AR facilitated more accurate and detailed lesion delineation, while neuronavigation often overestimated lesion size.

Conclusion

Augmented reality provides a faster and more accurate alternative for resection planning. Lesion delineation is more intuitive while remaining high in accuracy. Future research should focus on further intraoperative implementations.

P06.05.A Repeated intracranial administration of ipilimumab and nivolumab in patients with recurrent glioblastoma (rGB): A multi-cohort adaptive phase I clinical trial

Background

Perioperative intracerebral (iCE) administration of ipilimumab (IPI) and nivolumab (NIVO) in combination with IV NIVO was shown to be feasible, safe and associated with an encouraging survival benefit (Duerinck et al. JITC 2021). In subsequent cohorts, combination of iCE administration with biweekly intracavitary (iCA, via an Ommaya reservoir) administration of increasing doses of IPI and NIVO was investigated.

Methods

Three cohorts were defined according to resectability and postoperative treatment schedule. Patients (pts) in cohort-A and -C underwent a maximal safe resection, pts in cohort-B stereotactic biopsy only. All pts received iCE administration of 10 mg NIVO and 5 mg IPI at the end of the surgical intervention, after which an OR was implanted and an additional 10mg of NIVO and IPI (1, 5 or 10 mg) was administered iCA in cohort-C. All pts received biweekly postoperative NIVO 10 mg IV and iCA administrations of NIVO (3 dose levels were investigated in cohorts-A and -B: 1, 5, or 10 mg) for up to a maximum of 24w postoperatively. In cohort-C, 10 mg of NIVO was complemented with IPI (1, 5, or 10 mg). NGS and RNA gene expression profiling was performed on all tissue samples.

Results

In total, 44 pts were included (A: n= 16, B: n= 16, C: n= 12 recruitment ongoing). All pts in cohort-A and -B are off study treatment. All pts received the predefined dose of iCE IPI/NIVO and at least one administration of the predefined iCA dose. AE were infrequent and mostly not immune-related. Most common AE were fatigue(n=37), headache(n=25), confusion(n=18) and postoperative fever(n=15). Bacterial colonization of the Ommaya port occurred in 6 pts, subacute neurological deterioration requiring corticosteroids in 8 pts. There were no grade 5 AEs. Median PFS was 13w for cohort-A, 5w in cohort-B and 13w in cohort-C. Median OS is 43weeks in A, 29w in B and is not yet reached in cohort-C after median follow-up of 23w. OS did not differ significantly between study cohorts. OS of pts who underwent surgical resection (cohorts-A and -C) compared favorably to a historical cohort of 469 Belgian patients with rGB (treated in three prospective phase II clinical trials and a large multicenter early acces program for bevacizumab).

Conclusions

iCE followed by repeated iCA administrations of increasing doses of NIVO with/without IPI in rGB is feasible and safe without dose limiting AEs. A potential survival benefit seems restricted to pts amenable to surgical resection.

Petroclival meningiomas: update of current treatment and consensus by the EANS skull base section

BACKGROUND

The optimal management of petroclival meningiomas (PCMs) continues to be debated along with several controversies that persist.

METHODS

A task force was created by the EANS skull base section along with its members and other renowned experts in the field to generate recommendations for the management of these tumors. To achieve this, the task force reviewed in detail the literature in this field and had formal discussions within the group.

RESULTS

The constituted task force dealt with the existing definitions and classifications, pre-operative radiological investigations, management of small and asymptomatic PCMs, radiosurgery, optimal surgical strategies, multimodal treatment, decision-making, and patient's counselling.

CONCLUSION

This article represents the consensually derived opinion of the task force with respect to the management of PCMs.

A novel methodology for the determination of biomarker baseline levels in the marine polychaete Hediste diversicolor

Identifying environmental damage due to anthropogenic activities is a focal point for scientists and policy makers like those involved in the European Water Framework Directive (WFD). Many of these approaches focus on ecological endpoints for assessing environmental perturbations, which lead to policies emphasizing mitigation rather than prevention. Biomarkers provide early-warning indicators of stress but it is necessary to distinguish their natural variations from those induced by chemical stress. The global aim of this study was to establish a baseline assessment criterion (BAC) using historical data in a reference site to define toxicity thresholds. We have developed a multiple polynomial regression model (MPR) accounting the influence of salinity, temperature and size of individual on energetic reserves (glycogen and lipids) in the marine polychaete Hediste diversicolor. The model identified a complex, orthogonal relationship between confounding factors and glycogen and a linear relationship between lipids and size of individuals.

Acoustics and precondensation phenomena in gas-vapor saturated mixtures

Starting from fundamental hydrodynamics and thermodynamics equations for thermoviscous fluids, a new modeling procedure, which is suitable to describe acoustic propagation in gas mixtures, is presented. The model revises the boundary conditions which are appropriate to describe the condensation-evaporation processes taking place on a solid wall when one component of the mixture approaches saturation conditions. The general analytical solutions of these basic equations now give a unified description of acoustic propagation in an infinite, semi-infinite, or finite medium, throughout and beyond the boundary layers. The solutions account for the coupling between acoustic propagation and heat and concentration diffusion processes, including precondensation on the walls. The validity of the model and its predictive capability have been tested by a comparison with the description available in the literature of two particular systems (precondensation of propane and acoustic attenuation in a duct filled with an air-water vapor saturated mixture). The results of this comparison are discussed to clarify the relevance of the various physical phenomena that are involved in these processes. The model proposed here might be useful to develop methods for the acoustic determination of the thermodynamic and transport properties of gas mixtures as well as for practical applications involving gas and gas-vapor mixtures like thermoacoustics and acoustics in wet granular or porous media.

Coupling of Shear Acoustic Waves by Gratings: Analytical and Experimental Analysis of Spatial Periodicity Effects

A model, presented in a previous paper [J. App. Phys. 108 (2010) 074910], describing the modes coupling due to scattering on small one-dimensional irregularities (parallel ridges) of the surface of isotropic solid plates, when shear horizontal waves polarized along the ridges propagate perpendicularly to them, appears to be a convenient tool to tackle the effects of the shape profile of the ridges (including the depth and the slope). Being concerned by the use of this analytical approach not utilised until now, several results, yet typical of applications, are presented below and compared with some experimental and numerical results, even analytical results (from an alternative analytical model for particular cases). These comparisons permit to highlight the effects of spatial periodicities of the ridges and show that the method could provide information on geometrical parameters characterising the profile of the roughness, which could be of interest when other methods like optical methods cannot be used.

Bilateral Meckel's cave amyloidoma: a case report

Primary solitary amyloidoma of Meckel's cave is rare, and a bilateral location is even more rare. To the best of our knowledge, only 12 cases in the literature have described such a primary lesion, including one case of bilateral involvement of Meckel's cave. We report here on the case of a 57-year-old woman presenting with pseudotumor masses involving both Meckel's caves and responsible for trigeminal neuropathy. The final diagnosis of amyloidoma was made on the basis of histological examination of surgical biopsy specimens.

Solitaire stent for endovascular treatment of intracranial aneurysms: immediate and mid-term results in 15 patients with 17 aneurysms

INTRODUCTION

The Solitaire stent is the first fully retractable stent for endovascular treatment (EVT) of intracranial aneurysms. The aim of this study was to evaluate its use in a prospective series with mid-term follow-up.

METHODS

A retrospective review of our prospectively maintained database identified all patients treated with a Solitaire stent. Clinical charts, procedural data, angiographic results were reviewed.

RESULTS

Between June 2008 and September 2009, 15 patients with 17 wide-necked or fusiform aneurysms (16 unruptured/one ruptured) were identified. EVT was successfully performed in all but one patient in whom the stent was removed because it induced flow reduction in the 1.8-mm parent artery. Among 14 treated patients, 13 had an excellent outcome and one had a good outcome. In this latter patient, the first stent could not be delivered and was changed for another one that was successfully deployed. The patient experienced a thrombo-embolic complication 6 hours after EVT and kept a slight hand paresis. In all cases but one, the stent was thus easily navigated and positioned despite a relative poor visibility. Angiographic results included eight complete occlusions, two neck remnants, and six incomplete occlusions. Six-month control in 14 aneurysms showed 13 complete occlusions and one incomplete occlusion.

CONCLUSION

The Solitaire stent is useful for EVT of complex intracranial aneurysms because it is fully retractable, easy to navigate and to precisely place. However, it should be used with caution in arteries less than 2mm in diameter.

Endovascular treatment of anterior choroidal artery aneurysms

INTRODUCTION

Endovascular treatment (EVT) of anterior choroidal artery aneurysms (AChAA) may be challenging because of the close relationship with the parent artery. The aim of this study was to report our experience with EVT of AChAA.

METHODS

A retrospective review of our prospectively maintained database identified all AChAA treated by embolization. The clinical charts, procedural data and angiographic results were reviewed.

RESULTS

From April 2004-August 2008, 11 patients were identified. Five patients presented with a subarachnoid hemorrhage (SAH) and six patients were asymptomatic. Aneurysms size varied from two to 13 mm (mean size=3.6 mm) and nine had an unfavourable neck/sac ratio (>or=0.7). The anterior choroidal artery was arising from the sac (n=6) or from the neck (n=5). Endovascular treatment consisted of balloon-assisted coiling (n=8), coiling (n=2) and stent-assisted coiling (n=1). No procedural complication occurred and all patients had an excellent outcome except one patient who died because of severe vasospasm 8 days after an uneventful EVT. Immediate angiographic control showed six complete occlusions, one neck remnant and four incomplete occlusions. Follow-up controls (mean=18 months) were obtained in eight patients and showed five stable occlusions and three further thrombosis achieving complete occlusion.

CONCLUSION

EVT of AChAA is associated with very good clinical and long-term anatomical results. Because of their small size, unfavourable neck/sac ratio and close relationship with the parent artery, EVT frequently requires the use of adjunctive techniques such as balloon or stent-assisted coiling.

Endovascular treatment of intracranial aneurysms as the first thérapeutic option

BACKGROUND AND PURPOSE

To prospectively evaluate the results of endovascular treatment (EVT) of intracranial aneurysms when it is considered as first-intention treatment.

METHODS

From April 2004-October 2006, 167 consecutive patients with 202 aneurysms were treated in our institution. Five patients with a ruptured aneurysm with an associated haematoma were excluded. In 162 patients with 197 aneurysms, EVT was considered as first-intention treatment.

RESULTS

Surgical clipping was performed in 25 aneurysms (25/197=12.7%) including 22 aneurysms excluded from EVT and three EVT failures. EVT was thus attempted in 144 patients with 175 aneurysms and successfully performed in 141 patients with 172 aneurysms (172/197=87.3%). EVT failure rate was 1.7%. Clinical outcome according to the modified Glasgow Outcome Scale was: Excellent, 81.5%; Good, 7%; Poor or Fair, 3.5%; Death, 8%. Procedural complications occurred in 17 cases (10%). Balloon- or stent-assisted techniques were used in 60 cases (34.9%) and were not associated with higher complication rate. Overall procedural morbidity and mortality rates were 4.2 and 2.1%. Initially, complete occlusion was obtained in 68%, neck remnant in 23%, and incomplete occlusion in 9% of aneurysms. Follow-up (mean 11 months) was obtained in 119 aneurysms and showed major recanalisation--that required re-treatment--in 13 cases (11%) and minor recanalisation in 17 cases (14.3%).

CONCLUSION

Our findings suggest that new endovascular techniques allow proposing EVT as first-intention treatment in 87.3% of patients with intracranial aneurysms. This therapeutic strategy is associated with good clinical results. However, anatomical results are not improved and remain the EVT limiting factor.

Early surgery for brainstem cavernomas

BACKGROUND

The purpose was to review our experience with the surgical management of brainstem cavernomas (BSCs) and especially the impact of the surgical timing on the clinical outcome.

METHOD

We retrospectively reviewed 22 patients harboring a BSC, who underwent 23 procedures.

FINDINGS

Surgery was carried out during the early stage after the last haemorrhage, with a mean delay of 21.6 days (range 4-90 days). Sixteen procedures were performed after a first bleeding event while seven after multiple bleedings. Complete resection was achieved in 19 patients (86.4%). Early after surgery, 12 patients (52.2%) improved neurologically, 5 (21.7%) were stable and 6 (26.1%) worsened. New postoperative deficits were noted after 9 procedures (39.1%). Statistically significant factors for postoperative aggravation were: late surgery (P = 0.046) and multiple bleedings (P = 0.043). No patient operated on within the first 19 days after bleeding did worsen (n = 11), as opposed to 6 out of 12 who did when operated on later. After a mean follow-up of 44.9 months, 20 patients (90.9%) were improved, 1 patient (4.6%) was worse and 1 patient was lost to follow-up (4.6%), after reoperation for rebleeding of a previously completely resected cavernoma. Late morbidity was reduced to 8.6%. The mean Glasgow Outcome Scale (GOS) at the end of the follow-up period was 4.24, compared to a mean preoperative GOS of 3.22 (P<0.001). Complete neurological recovery of motor deficits, sensory disturbances, cranial nerves (CNs), internuclear ophtalmoplegia and cerebellar dysfunction were respectively 41.7%, 38.5%, 52.6%, 60.0% and 58.3%. Among the most affected CNs: CN 3, CN 5 and CN 7 were more prone to completely recover, respectively in 60.0%, 70.0% and 69.2%.

CONCLUSIONS

Surgical removal of BSCs is feasible in experienced hands with acceptable morbidity and good outcome. Early surgery and single bleeding were associated with better surgical results.

Experimental and theoretical study of processes leading to steady-state sound in annular thermoacoustic engines

This paper gives a simplified analytical description of spontaneous generation and finite amplitude saturation of sound in annular thermoacoustic engines, and also provides comparison with experiments. The model includes the precise description of thermoacoustic amplification of sound (induced by interaction between an heterogeneously heated stack of solid plates and resonant gas oscillations), which accounts for the details of the temperature distribution in the whole thermoacoustic device (i.e., which does not only account for the mean temperature gradient along the stack). The saturation of the acoustic wave amplitude is described by taking into account both the reverse influence of high amplitude acoustic field on temperature field, and the dissipation of acoustic energy due to higher harmonics generation and minor losses (vortex generation). From the comparison between simulation results and experiments, it is demonstrated that the dynamical behavior observed in our experimental device is predominantly controlled by the effects of acoustic streaming and acoustically enhanced thermal conductivity tending not only to reduce the externally imposed temperature gradient along the stack, but also to change the shape of the temperature field.

[A new area for radiotherapy with favourable features]

Radiotherapy is a complex medical speciality involving technology research, biology research and clinical research. All these basic researches are performed in order to optimise the management of cancer treatment patients. The aim of the present review is to present radiotherapy as a moving speciality whatever the concerned section. It will be particularly described the new approaches in terms of technology but also clinical developments.

Anterior cervical interbody fusion with hydroxyapatite graft and plate system

Object

In cases of spondylosis or spine trauma, cervical interbody grafts are sometimes required after anterior discectomy. To avoid morbidity related to the harvesting of iliac crest bone, numerous materials have been developed such as allografts, methylmethacrylate, biocompatible osteoconductive polymer, and coralline grafts or cages. Some of these materials, however, are inefficient for fusion or are associated with specific complications. Conversely, hydroxyapatite (HA) grafts have numerous advantages. For example, their mechanical properties provide adequate load resistance and their porosity allows infiltration by newly formed bone, leading to complete fusion. The authors studied the results of using HA grafts combined with plating in patients who underwent anterior cervical discectomy.

Methods

Fifty-four patients underwent 68 cervical interbody fusion procedures in which an HA graft and plating were used. Indications for surgery were radiculopathy (caused by soft-disc herniation or spondylosis) in 46 cases, spondylotic myelopathy in two cases, and spinal trauma in six cases. Postoperatively the patients were followed for a mean of 24.6 months. Patients underwent radiography to evaluate fusion, intervertebral disc height, and the degree of lordosis.

Clinically, excellent or good results (based on the Odon classification) were demonstrated in 91% of patients who presented with radiculopathy. Complete interbody fusion was achieved in 99% of all cases. Preoperative kyphotic deformities were corrected in all cases after surgery. Intervertebral disc height was maintained throughout follow up. Surgery-related morbidity was low; only one patient suffered from a permanent dysphagia. Graft deterioration was observed in 13 cases and two graft fractures occurred but without adversely affecting fusion. There were no cases of graft extrusion.

Conclusions

Hydroxyapatite grafts are very efficient in achieving cervical fusion, maintaining intervertebral disc height, and restoring lordosis. When combined with the placement of a cervical plate, immediate stability is achieved and graft displacement is prevented.

Acoustic streaming in annular thermoacoustic prime-movers

The theory of acoustic streaming in an annular thermoacoustic prime-mover is developed. It is predicted that above the threshold for traveling wave excitation the device considered (which does not contain any moving parts or externally imposed pressure gradients) produces circulation of fluid. The heat flux carried by this directional mass flow inside the thermoacoustic stack exceeds (or is comparable with) the heat flux associated with the acoustically induced increase of thermal diffusivity of the gas. The effects investigated are important for optimization of the performance of thermoacoustic devices.

Long-term survival after aortic valve replacement for native active infective endocarditis

BACKGROUND

The objective of this study was to analyse the impact of acute surgery for native aortic valve endocarditis and its influence on the long-term prognosis after surgery.

METHODS

A total of 161 patients underwent aortic valve replacement for native active aortic valve endocarditis (NAAVE) during a 29-year period, from 1967 to 1995 (age range: 10 to 72 years; mean 48 +/- 12). The main indication for surgery was progressive congestive heart failure (76%). Other indications were untreatable sepsis (27%), peripheral or central emboli (12%) and, from 1978, echocardiographic evidence of friable, pedunculated vegetations (3%). Streptococcal and staphylococcal infections predominated. Concomitant procedures were performed in 27% of the patients, including mitral and tricuspid valve surgery and coronary bypass procedures.

RESULTS

Operative mortality was 8% in the majority of cases caused by heart failure or multi-organ failure. Multivariate logistic regression analysis identified NYHA class IV to be an independent predictor for postoperative death. Long-term survival for discharged patients was 75% at 10 years and 58% at 15 years, with a mortality rate of 3.6%/patient/year. Cox regression analysis identified the year of operation, trivalvular endocarditis and staphylococcal infection as independent predictors of survival. At 10 and 15 years after aortic valve replacement, 91% and 84% of the patients, respectively, were free of recurrent endocarditis. The presence of an abscess cavity at first operation was found to be predictive of recurrent endocarditis.

CONCLUSIONS

Valve replacement for NAAVE offers a good chance for a cure and satisfactory long-term survival. Improvements in pre- and per-operative management of the very ill patient, and the use of allograft valves are likely to further improve long-term results. Finally, the presence of staphylococcal endocarditis requires long-term postoperative antibiotic therapy.

Popliteal-to-distal bypass grafts for limb salvage

From July 1989 to July 1994, a total of 44 popliteal-to-distal artery bypasses were performed in 36 patients (29 men and seven women, mean age 62 +/- 10 years). These procedures accounted for 8.8% of all infrainguinal revascularizations performed during that period. Risk factors included diabetes in 33 patients (92%), smoking in 18 (50%), and coronary artery disease in 15 (42%). Prior to revascularization all patients were at risk of limb loss. Tissue necrosis was present in 31 cases (71%), ulceration in eight cases (18%), and rest pain in five cases (11%). Patency of the femoral and popliteal arteries was confirmed prior to surgery in all cases. Intraoperative percutaneous angioplasty of the superficial femoral artery was performed in three cases. Proximal anastomosis was made to the distal popliteal artery in all cases. A total of 52 distal anastomoses (eight sequential bypasses) were made on the following arteries: posterior tibial artery in 13 cases, anterior tibial artery in eight cases, peroneal artery in six cases, plantar artery in two cases, and dorsalis pedis artery in 21 cases. The greater saphenous vein was used as graft material in 42 cases (95%) and the lesser saphenous vein in two cases (5%). No patient died during hospitalization. Early bypass occlusion occurred in three cases (6.8%) and led to amputation in all cases. Secondary patency and limb salvage rates at 3 years calculated using the actuarial method were 74% and 82% respectively. Bypass thrombosis due to superficial femoral artery deterioration was not observed in any case. The present study indicates that popliteal-to-distal artery bypass is a simple, durable, and low-risk method of lower limb revascularization. Medium-term results are promising and support routine use of popliteal-to-distal artery bypass for limb salvage in patients without significant stenosis of the superficial femoral artery.

Surgical treatment for acute native aortic valvular infective endocarditis: long-term follow-up

During the period 1970-1993, 116 patients (63 men, 53 women) with native aortic valvular infective endocarditis were treated surgically. The mean age was 37 years. The main causative organisms were streptococci and staphylococci. Indication for surgery was cardiac failure (70 cases), uncontrolled sepsis (30), peripheral emboli (11) and overwhelming destruction of the aortic valve (five). Hospital and late mortality rates were 8% and 11% respectively. Patients who died in hospital and those who presented a paravalvular leakage had a ring abscess associated with aortic wall destruction. Among 34 patients screened for cerebral septic emboli the condition was confirmed in 15, of whom six were symptom-free. Thus, it is believed that in the presence of root abscess, surgery should be undertaken promptly, regardless of the cardiac status. It is confirmed that cerebral septic emboli should be systematically screened for in the presence of any infective endocarditis.

Blood chemistry of normal human fetuses at midtrimester of pregnancy

Thirteen biochemical parameters and five enzymatic activities were determined on sera of 63 normal human fetuses sampled by direct puncture under ultrasound guidance, between the 20th and the 26th wk of gestation, and on their mothers. They were referred to us for various prenatal diagnoses but were well and confirmed healthy at birth. Some parameters were found to be very similar in both groups, mainly creatinine, calcium, creatine kinase, aspartate aminotransferase, and gamma-glutamyl transferase. Some values were significantly higher in the fetuses, such as total bilirubin, direct bilirubin, phosphorus, lactic dehydrogenase and alkaline phosphatase activities, and alpha-fetoprotein. Urea, uric acid, glucose, triglycerides, cholesterol, total protein, and albumin levels were found to be lower in fetuses. These data indicate a slower metabolism in fetuses compared to their mothers, a lower level of energy requirement, and a relative liver immaturity. These normal values of fetal biochemistry will improve our knowledge of physiology and help to determine the specific values of a test in fetal pathology.

[Urinary excretion of lithogenic substances in hospitalized patients with calcium lithiasis. Physiopathologic meaning and prognostic value]

The urinary excretion of various substances involved in kidney stone formation was evaluated in 67 patients with hypercalciuric lithiasis (HCl), 36 lithiasis patients with normal calciuria (NCl) and 21 controls without urinary stones. All subjects were hospitalized for 3 days and given a calcium, phosphorous and sodium-controlled diet. The 24-hour urine volume was significantly larger in the HCl and NCl groups than in controls. The 24-hour Ca, Na and uric acid excretion was significantly greater in the HCl group than in the NCl and control groups. Oxalate and pyrophosphate excretion was the same in all three groups. Urinary Ca correlated with urinary creatinine in the HCl and control groups, but the slope and ordinate of the regression line were significantly higher in the former group. Similarly, urinary Na correlated with urinary creatinine in the HCl and control groups with a significantly steeper slope in the HCl group. These data are suggestive of abnormalities in the tubular reabsorption of Ca and Na in HCl patients. Finally, there was no correlation between the values obtained and the activity of the disease, as evaluated by the finding of at least 3 urinary stones or one staghorn calculus during the 5 years preceding the study. It is concluded that measurements of Ca, Na, uric acid, creatine, oxalates and phosphates during a stay in hospital provide pathophysiological information but cannot be taken as indices of urolithiasis activity.

[In vitro supplementation of pyridoxal phosphate for the optimisation of the determination of the catalytic activity of alanine aminotransferase and aspartate aminotransferase in kidney transplant patients (author's transl)]

Pyridoxal phosphate (PLP) is the coenzyme of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Thus, in vitro supplementation with PLP is important for the optimisation of the determination of catalytic activity of both enzymes. It patients with kidney transplants, stimulation by PLP is very important for ALT activity, which could be affected by plasma PLP deficiency. Furthermore, in this population catalytic activities are more frequently found increased using methods with PLP supplementation than without PLP supplementation (56% and 71% of patients for AST and ALT, respectively). These differences are not related to HBs antigen.

[Electrophysiologic abnormalities in chronic alcoholism, disclosed by the methods of evoked potentials and Hoffman's reflex. Study of a possible metabolic pathogenesis]

During a preliminary study comparing 5 normal subjects and 5 alcoholics (25 experiments) changes in evoked potentials were found in these patients. There was mainly a reduction in these potentials during the first 100 milleseconds following stimulation. Such a reduction generally means a disorder of the arrival of the influx at the level of the cortex and may be found mainly in peripheral nerve involvement. A complementary study of the H reflex (34 experiments) showed that this reflex was affected in 60% of chronic alcoholics whether or not they had liver cirrhosis. The theory according to which the EEG abnormalities observed may be linked to a metabolic disorder of the amino-acids was not confirmed. The changes of the first 100 milleseconds of the evoked potential associated with the change in Hoffman's reflex are in favour of early peripheral involvement even in alcoholics who do not appear to have any peripheral neuritis. These signs are different from those which are observed in marijuana or psylocybine poisoning where the EEG signs are due to central involvement.