PMMA Bone Cement in Interventional Oncology.

Polymethylmethacrylate (PMMA) bone cement is increasingly being used for percutaneous minimally invasive treatments of patients suffering from bone malignancies. PMMA is composed of a polymeric powder and a monomeric liquid. Once mixed, the polymerization process begins and leads to a viscous fluid that can be injected through a bone trocar. Cement progressively hardens within the bone, leading to a viscoelastic solid material. PMMA interacts with the surrounding cancellous bone through mechanical interlocking via interdigitations in trabecular bone. It can also bond with hardware, such as titanium screws, as it penetrates the macro- and micro-irregularities of the hardware. PMMA itself has no antineoplastic effects but may be used as a stand-alone treatment to provide pain palliation and bone consolidation through mechanical reinforcement, notably in areas with high compression load. It can also be used to reinforce the anchorage of screws in case of a landing zone with poor bone quality due to underlying malignant osteolysis.

Percutaneous image-guided double oblique anterior approach to the acetabulum for cementoplasty.

AIM: To report the technique of percutaneous double oblique anterior access to the acetabulum and evaluate its feasibility and safety. MATERIALS AND METHODS: Pelvic computed tomography (CT) examinations of 60 patients (30 men and 30 women; mean age 62.6±13.2 years) were retrieved randomly from the picture archiving and communication system (PACS). A virtual intraosseous trajectory was defined on both sides on the axial CT images with the entry point marked 1 cm above the anterosuperior iliac spine and the endpoint defined just above the level of the ischial spine at the midpoint of the posterior acetabulum. Patient age, sagittal oblique angulation, axial oblique angulation, length of intraosseous trajectory, distance from the hip joint, thickness of the iliac bone cortex, and intervening structure(s) between the skin and the bone entry points were recorded. RESULTS: The mean sagittal and axial oblique angulations were 34.2±4.5° and 31.5±6.7°, respectively, and mean length of the intraosseous trajectory was 11.8±0.9 cm. The axial oblique angle and length of the intraosseous trajectory were significantly lower in the female than the male population (p<0.05). None of the virtual trajectories traversed the hip joint. In 112/120 trajectories (93.3%), there were no cortical breaches in the iliac bones. In eight trajectories in four patients, the virtual trajectory crossed either the medial iliac cortex (4/120; 3.3%) or the medial iliac cortex and the iliacus muscle (4/120; 3.3%). CONCLUSION: The anterosuperior iliac and ischial spines can be used safely and reliably as landmarks to perform the double oblique anterior approach.

Percutaneous extra-spinal cementoplasty in patients with cancer: A systematic review of procedural details and clinical outcomes.

PURPOSE: To perform a systematic review of technical details and clinical outcomes of percutaneous extra-spinal cementoplasty in patients with malignant lesions. MATERIALS AND METHODS: PUBMED, MEDLINE, MEDLINE in-process, EMBASE and the Cochrane databases were searched between January 1990 and February 2019 using the keywords «percutaneous cementoplasty¼, «percutaneous osteoplasty¼ and «extra-spinal cementoplasty¼. Inclusion criteria were: retrospective/prospective cohort with more than 4 patients, published in English language, reporting the use of percutaneous injection of cement inside an extra-spinal bone malignant tumour using a dedicated bone trocar, as a stand-alone procedure or in combination with another percutaneous intervention, in order to provide pain palliation and/or bone consolidation. RESULTS: Thirty articles involving 652 patients with a total of 761 lesions were reviewed. Mean size of lesion was 45mm (range of mean size among publications: 29-73mm); 489 lesions were located in the pelvis, 262 in the long bones of the limbs and 10 in other locations. Cementoplasty was reported as a stand-alone procedure for 60.1% of lesions, and combined with thermal ablation for 26.2% of lesions, implant devices for 12.3% of lesions, and balloon kyphoplasty for 1.4% of lesions. The mean volume of injected cement was 8.8mL (range of mean volume among publications: 2.7-32.2mL). The preoperative visual analogic scores ranged between 3.2 and 9.5. Postoperative scores at last available follow-up ranged from 0.4 to 5.6. Thirteen papers reported a reduction of the visual analogic scores of 5 points or more. Nerve injury was the most frequent symptomatic leakage (0.6%). CONCLUSION: Percutaneous extra-spinal cementopasty is predominantly performed as a stand-alone procedure and for lesions in the bony pelvis. It appears to be an effective tool to manage pain associated with malignant bone tumours. There is however a lack of standardization of the technique among the different publications.

A custom robot for Transcranial Magnetic Stimulation: first assessment on healthy subjects.

In this paper, a custom robotic system for Transcranial Magnetic Stimulation is assessed in clinical conditions on healthy subjects. A motor cortex mapping is performed using the robotic system with comparison to a manual approach using a neuronavigation system. Stimulation accuracy, repeatability are evaluated as well as the feeling of the system operator and the subject in terms of comfort, tiredness, stress level, ease-of-use. Very encouraging results are obtained on all these aspects, which strengthens the idea of developing robotic assistance for TMS.

Design considerations for a novel MRI compatible manipulator for prostate cryoablation.

PURPOSE: Prostate carcinoma is a commonly diagnosed cancer in men. Nonsurgical treatment of early stage prostate cancer is an important alternative. The use of MRI for tumor cryoablation is of particular interest: it offers lower morbidity compared with other localized techniques. However, the current manual procedure is very time-consuming and has limited accuracy. A novel robotic assistant is therefore designed for prostate cancer cryotherapy treatment under MRI guidance to improve efficiency and accuracy. METHODS: Gesture definition was achieved based on actions of interventional radiologists at University Hospital of Strasbourg. A transperineal approach with a semiautonomous prostatic cryoprobe localization procedure was developed where the needle axis is automatically positioned before manual insertion. The workflow was developed simultaneously with the robotic assistant used for needle positioning. RESULTS: The design and the associated workflow of an original wire-driven manipulator were developed. The device is compact and has a low weight: its overall dimensions in the scanner are 100 × 100 × 40 mm with a weight of 120 g. Very good MRI compatibility was demonstrated. CONCLUSIONS: A novel cryoablation procedure based on the use of a robotic assistant is proposed. The device design was presented with demonstration of MRI compatibility. Further developments include automatic registration and in vivo experimental testing.

Fully automated image-guided needle insertion: application to small animal biopsies.

The study of biological process evolution in small animals requires time-consuming and expansive analyses of a large population of animals. Serial analyses of the same animal is potentially a great alternative. However non-invasive procedures must be set up, to retrieve valuable tissue samples from precisely defined areas in living animals. Taking advantage of the high resolution level of in vivo molecular imaging, we defined a procedure to perform image-guided needle insertion and automated biopsy using a micro CT-scan, a robot and a vision system. Workspace limitations in the scanner require the animal to be removed and laid in front of the robot. A vision system composed of a grid projector and a camera is used to register the designed animal-bed with to respect to the robot and to calibrate automatically the needle position and orientation. Automated biopsy is then synchronised with respiration and performed with a pneumatic translation device, at high velocity, to minimize organ deformation. We have experimentally tested our biopsy system with different needles.

Electrophysiological analysis of pudendal neuropathy following traction.

Pudendal neuropathy is an unusual but important complication of orthopedic surgical procedures involving traction on the fracture table. We describe the clinical and electrophysiological features in six patients presenting with perineal sensory disorders and sexual dysfunction following surgical repair of femoral fracture, hip dislocation, or intra-articular foreign body, in which the traction table was used. All underwent electrophysiological recordings: bulbocavernosus muscle electromyography (EMG), measurements of the bulbocavernosus reflex latencies (BCRLs), somatosensory evoked potentials of the pudendal nerve (SEPPNs), sensory conduction velocity of the dorsal nerve of the penis (SCVDNP), and pudendal nerve terminal motor latencies (PNTMLs). Signs of denervation localized to the territory of the pudendal nerve were found in 3 patients, normal BCRL in 6, abnormal SEPPNs in 4, and abnormal SCVDNPs and PNTMLs in all cases. The outcome at 2-year follow-up was good, except in one patient with initially unrecordable PNTML. Perineal electrophysiological examination can thus confirm the pudendal neuropathy and give prognostic information.

[Suprapubic reflex. Electrophysiological study in normal patients]. / Le réflexe pubo-caverneux. Démonstration électrophysiologique.

INTRODUCTION: In spinal cord injuries patients, tapping the suprapubic aera is a strong stimulus to ellicit detrusor contraction and can be used in the management of neurogenic bladder. This stimulation also determines a perineal muscles contraction. This striated response was mentionned in animal studies but never specifically analysed in men especially in normal subjects. AIMS OF THE STUDY: Our objective was to describe pelvic floor responses with measurement of reflex latency following suprapubic mechanical stimulation. METHODS: 21 patients without neurological disease were studied. They were 14 women and 7 men. Mean age was 51 (SD=14,2). Motor responses were recorded with a needle electrode inserted in the left bulbocavernosus muscle. Stimulation was delivered with an electromechanical hammer, tapping directly on the suprapubic aera. RESULTS: A polyphasic muscular response was always and easily elicited in all patients. Mean latency was 67,5 ms. (SD = 14,7). The reproducibility between the first and second mechanical responses was good with no statistical difference (r=0,966; p=0,0001). DISCUSSION: Our study clearly demonstrates a suprapubic bulbocavernosus reflex (SBR). Many arguments can be retained for a polysynaptic reflex (polyphasic response, habituation and short latency of the reflex, mean latency in the habitual values of R2 responses following electrical stimulation of the dorsal nerve of the penis). We hypothetize that: the true stimulus is the stimulation of the bladder wall tenso-receptors; integration level of the SBR is the sacral segments and the efferent limb the pudendal nerve; afferent pathways could be vehicled by pelvic nerve fibers. CONCLUSION: Competition between a preponderant (or exaggerated) SBR and a bladder contraction following suprapubic tapping, may constitute a real functional outlet obstruction giving incomplete or complete retention in some suprasacral bladders. In normal subjects, SBR can be considered as a continence reflex with increase of perineal tone following the stimulation of the bladder wall tenso-receptors during stress.

Bladder cooling reflex in patients with multiple sclerosis.

PURPOSE: We describe the effect of intravesical ice water instillation in patients with multiple sclerosis and without an overactive bladder. MATERIALS AND METHODS: Of 131 consecutive patients with multiple sclerosis who presented with a urinary disorder we selected for study 10 men and 29 women with a mean age plus or minus standard deviation of 50 +/- 9 years who had multiple sclerosis without an overactive bladder. Nonoveractive bladder was defined as no involuntary detrusor contraction up to 400 ml. of maximum fill on routine cystometry. We performed cystometry with saline at 25 to 30C at an infusion rate of 50 and 100 ml. per minute, and with ice water at 0 to 4C at a rate of 100 ml. per minute. Ice water cystometry was considered positive when an involuntary detrusor contraction occurred before 200, and between 200 and 400 ml. of filling. Ice water cystometry was considered negative when there was no involuntary detrusor contraction during ice water filling up to 400 ml. RESULTS: Ice water cystometry enabled us to elicit involuntary detrusor contractions in 21 patients, which remained undetected by warm water cystometry at rates of 50 and 100 ml. per minute. The test was positive before 200, and between 200 and 400 ml. in 10 and 11 cases, respectively. Positive ice water cystometry was significantly associated with irritative signs or significant post-void residual urine volume. CONCLUSIONS: An involuntary detrusor contraction was not elicited by cystometry at 50 or 100 ml. per minute, implying that the afferent mechanoreceptor reflex limb via ADelta fibers is not involved. In contrast, ice water cystometry at 100 ml. per minute elicited an involuntary detrusor contraction, suggesting involvement of an afferent reflex limb via capsaicin sensitive C fibers. These involuntary detrusor contractions revealed by ice water cystometry are probably relevant to an overactive bladder. In urinary disorders such a positive test indicates a spinal lesion. In multiple sclerosis it may have pathophysiological value, indicating a spinal rather than cerebral mechanism of overactive bladder, and diagnostic value, indicating multifocal demyelination.

[Clinical evaluation of female urinary incontinence]. / Evaluation clinique de l'incontinence urinaire de la femme.

EXAMINATION: Clinical evaluation of stress and urge incontinence is always necessary before therapeutic decisions. Full bladder examination may reveal stress incontinence during cough when cervico-urethral hypermobility is suspected, and leak during Vasalva manoeuvre when incontinence is due to intrinsic sphincter deficiency. OBJECTIVE SCORES: Pad test objectives the quantitative importance of incontinence. Symptom scores allow intra and inter individual comparisons. Psychosocial implications are studied with specific quality of life scales. They allow better therapeutic strategies in the management of urge and stress urinary incontinence. Objective evaluation of the different treatments and medico-economic approach of incontinence are thus possible.

Postpartum lumbosacral plexopathy limited to autonomic and perineal manifestations: clinical and electrophysiological study of 19 patients.

The objective was to describe perineal electrophysiological findings and to determine their diagnostic value in a type of lumbosacral plexopathy after vaginal delivery, which only involves the lower part of the plexus (S2-S4). Consecutive female patients referred to an outpatients' urodynamic clinic were the source. Nineteen previously healthy women, 13 multiparae and six para 1, were investigated. Mean age was 33.7 (SD 5.4) (range 28-41) years. All of them presented with urinary (stress incontinence 14, dysuria five), anorectal (faecal incontinence eight, dyskesia one), or sexual dysfunctions (hypoorgasmia or anorgasmia six) after vaginal delivery. No associated lower limb sensory or motor deficits were noted. All the patients had electrophysiological recordings (bulbocavernosus muscle EMG, measurements of the bulbocavernosus reflex latencies (BCRLs), somatosensory evoked potentials of the pudendal nerve (SEPPNs), and pudendal nerve terminal motor latencies (PNTMLs)). Cystometry and urethral pressure profile (UPP) were performed in the 14 patients with stress urinary incontinence. Perineal electrophysiological examination disclosed signs of denervation in the perineal muscles in all the cases, prolonged BCRLs in 17/19, and abolished BCRLs in 2/19, abnormal SEPPN in 1/19, and normal PNTMLs in all the patients. Urodynamic investigations disclosed low urethral closure pressure for age (< 50 cm H(2)O) in half of the patients. In conclusion, Lower postpartum lumbosacral plexopathy is evoked when perineal sensory disturbances whether or not associated with urinary or faecal incontinence persist after a history of a difficult vaginal delivery. Electrophysiological investigations precisely identify the site of the lesion and demonstrate distal innervation integrity.

Comparison of two modes of administration of a personalized quality of life scale in a longitudinal study of total hip arthroplasty.

UNLABELLED: Quality of life scales are being increasingly used to evaluate patients. The earliest scales were standardized questionnaire that did not necessarily provide an optimal evaluation of the quality of life of each individual patient. A number of personalized scales are now available, including the SEIQoL, in which the patients nominate the five quality of life areas most important to them. The SEIQoL has been validated. We tested the SEIQoL in patients treated by total hip arthroplasty, a procedure that is expected to improve quality of life. OBJECTIVE: To compare two methods of administration of the SEIQoL several months after total hip arthroplasty. METHODS: The SEIQoL was administered before and after the arthroplasty. During the postoperative test session, the SEIQoL was administered twice, once using the items nominated preoperatively and once after allowing the patient to repeat the nomination procedure. RESULTS: With both methods, significant improvements in quality of life were demonstrated (P < 0.05). There was no significant difference between the two methods. CONCLUSION: Changing the items of the SEIQoL during prospective studies does not modify the overall quality of life score. Keeping the same items throughout the study is nevertheless warranted.

Analysis of the perception of and reactivity to pain and heat in patients with wallenberg syndrome and severe spinothalamic tract dysfunction.

BACKGROUND: The aim of the study was to assess the consequences of severe spinothalamic tract lesions resulting from lateral medullary infarct and to show that a specific pain perception can be elicited by strong thermal stimulation. CASE DESCRIPTIONS: Both patients examined presented with severe thermoalgic dissociation of the limbs contralateral to the lesion, with normal discriminative somatosensory perception and motor strength. They reported pain perception when touching very warm (>50 degrees C to 60 degrees C) objects and a brisk, occasionally uncontrolled withdrawal reaction of the arm and hand under the same conditions, without any perception of the heat nature of the stimulus. Warm stimulation, <45 degrees C, elicited no thermal perception or discrimination. Pain perception could be elicited in both patients by increasing the temperature, with a reproducible threshold of 47 degrees C to 49 degrees C. Pain always occurred after a prolonged delay of 8 to 10 seconds in response to threshold heat, and was described as deep and osseous, and clearly different from that perceived on the nonaffected side. The delay was much shorter when the temperature was increased by 4 degrees C to 5 degrees C. Cold stimulation elicited similar pain perception in one patient. Analysis of subjective perception of laser stimulation showed a much higher pain threshold on the affected hand. There were no laser-evoked potentials on this side, which suggested major spinothalamic injury. Assessment of the RIII noxious reflex revealed persistent response withdrawal reactions, with an increased threshold on the affected side, and partial consciousness of the noxious nature of the stimulus. CONCLUSIONS: To our knowledge, this is the first description of the appearance of pain perception of high temperatures in patients with severe spinothalamic injury who are suffering from a complete loss of temperature perception. This implies that noxious thermal stimulation can still be perceived via extra spinothalamic pathways (which are slow and multisynaptic), such as the spinoreticulothalamic tract. Patients with Wallenberg syndrome should be informed and made aware of their residual perception of and reactions to noxious stimulation.

[Anti-nidation activity of oral contraceptives]. / L'activité antinidatoire des contraceptifs oraux.

The antinidatory activity of the oral contraception is generally unknown: the contraceptive pill mainly prevents the gametes from meeting. However, pregnancies under pill indicate conception of embryos. Besides, missed pills protocols sometimes record ovulatory escape. We suggest the computation of an Embryo Destruction Index (EDI), in order to measure the antinidatory effect of two categories of oral contraceptives: combined estroprogestatives and microprogestatives.

[The antinidatory activity of oral contraceptives]. / L'activite antinidatoire des contraceptifs oraux.

PIP: This work examines the importance of the antinidatory effect of combined and low-dose progestin oral contraceptives (OCs). The greater importance of inhibition of ovulation and coagulation of the cervical mucus as mechanisms of action of OCs has caused the role played by transformations of the endometrium to be neglected. But the hormone-induced inhospitability of the endometrium to implantation of the accidentally fertilized embryo should be assessed because of the occasional occurrence of pregnancies in women using pills and because inhibition of ovulation is never complete, especially in the case of low-dose progestins which only prevent ovulation half the time. Ovulation inhibition is very powerful in principle when no pills are forgotten. Some research using the techniques of "programmed forgetting" has indicated that inhibition is not complete in all users, especially when one or more pills are skipped. Elevated serum concentrations of estradiol, the pituitary gonadotropins, and progesterone have been reported. Research suggests that the cervical mucus and endometrial effects are not significantly influenced by pill forgetting. The Pearl indexes of different OC formulations attest to the occurrence of pregnancy in women using pills. Most reported Pearl indexes are corrected to account for pill forgetting. Some surveys suggest that forgetting pills is not rare, and it may be argued that uncorrected Pearl indexes would be a more reliable reflection of actual conditions of use. The uncorrected Pearl index might be one or two pregnancies per 100 woman-years during standard use including inevitably some forgetting. In the absence of easily used markers to detect the presence of an embryo before implantation, the antinidatory effect of endometrial atrophy cannot be directly demonstrated. It may be hypothesized that the antinidatory effect is a kind of resistance of the endometrium to implantation. In other words, a much smaller proportion of embryos conceived under OCs would successfully be able to implant than would be true under conditions of no OC use. The "index of embryonic destruction" based on current knowledge of uncorrected Pearl indexes, can be estimated at 3 to 10 embryos destroyed for one or two pregnancies per 100 woman-years of use of combined OCs and 6 to 30 per 100 woman-years of use of low-dose progestins.^ieng