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M Limousin

Publications and source records attributed to M Limousin.

At least 19 recordsLinked to original sources
PubMed2006

Anatomic bases of vascularized elbow joint harvesting to achieve vascularized allograft.

In order to later make precise the operative technique of free vascularized elbow allograft transfer, the anatomic conditions necessary for the success of such an operation are reviewed. The exact topography of the nutrient foramina of the humerus, radius, and ulna has been specified on 102 dry bones. The osseous resection at the recipient will have to be carried out on these aspects: nutrient foramina of the three bones of the elbow (at 9 cm from medial epicondyle for the humerus; at 8 cm for the two bones of forearm) in order to preserve diaphysary vascularization of the recipient. A study of arterial and venous vascularization carried out on 18 anatomic specimens showed that the osseous ends were irrigated by a periosteal arterial network and were drained in the centromedullary cavities. Systematization of the arteriovenous blood supply of the distal end of the humerus and proximal ends of the two forearm bones is proposed after dissection of 18 anatomic specimens. Arterial periosteal territories are defined. The importance of each peri articular arteriole is estimated according to the surface of its respective section. A radial, constant, and musculoperiosteal collateral artery from the brachial artery is described. It accounts for 12% (+/- 3%) of the total contribution. The recurrent radial artery is the most significant: 31% (+/- 9%) of the total contribution. The profunda brachii artery is negligible: 4% (+/- 2%) of the total contribution. As well for vascular as mechanical reasons, osteosynthesis will have to be carried out using screwed plates, the optimal location of which is specified according to the arterial periosteal cartography. Ulnar and radial nerves and, to a lesser extent, the median nerve can be harvested "en bloc" preserving their vascular supply in order to make vascularized grafts of them. Free vascularized elbow allograft transfer is technically possible, if one respects these anatomic bases.

Arterioles↗
PubMed2005

[Osteoma osteoid of the trapezoid bone: a case-report and review of the literature].

Osteoid osteomas are often localised in long bones but only rarely in the carpus. This is a case report of an osteoid osteoma in the trapezoid. Diagnosis was difficult and established late, due to misleading initial symptoms. Radiological examination allowed localisation of the nidus. For osteoid osteoma localised in a carpal bone, we recommend total removal without bone-graft or arthrodesis.

Adult↗
PubMed2005

[Long-term outcome of non-vascularized grafts for carpal scaphoid nonunion: 58 cases with 8.8 year follow-up].

PURPOSE OF THE STUDY: We conducted this retrospective study to analyze outcome obtained in 58 cases of carpal scaphoid nonunion treated with a non-vascularized corticocancellous graft. Our objective was to search for factors influencing outcome and identify appropriate indications. MATERIAL AND METHODS: Between 1984 and 1999, 103 patients were treated with a non-vascularized corticocancellous graft. Fifty-seven patients (58 wrists) were retained for analysis (4 deaths, 30 not attending follow-up consultation far from their residence, and 12 lost to follow-up). Mean follow-up was 106 months (range 19-212). Mean age was 36 years (20-62). Mean time to diagnosis of fracture was 35 months (6-252); the fracture was not recognized initially in 45 patients. According to the Schernberg classification, fractures were localized in zone II (n = 11), zone III (n = 40), and zone IV (n = 7). Using the Alnot classification, nonunion was grade I (n = 13), grade IIA (n = 20), grade IIB (n = 22), grade IIIA (n = 2), and grade IIIB (n = 1). Mean immobilization after grafting was 2.7 months. RESULTS: At three months, bone healing was achieved in 42 wrists. Thirty-six patients were very satisfied, 18 satisfied and four not satisfied. Twenty-seven patients presented significant pain at the graft harvesting site which regressed in all. There were no harvesting sequelae. Compared with the healthy wrist, we noted reduced flexion (8.7 degrees on average), extension (12.8 degrees on average), and radial inclination (10.5 degrees on average). Other wrist motions were not affected, particularly pronation and supination. The index of carpal height was 0.54 on average (range 0.47-0.57); carpal height was diminished in nine wrists. The radiolunate angle was 4.8 degrees on average (-17 degrees to +27 degrees). Dorsal intercalated segmental instability (DISI) was noted in twenty wrists. Bone healing was not achieved in eleven wrists, seven of which presented initial necrosis of the proximal pole. Pain improved in all patients. Persistence of DISI favored osteoarthritic degeneration. DISCUSSION: With this technique, we achieved bone healing in 81% of the cases. Non-vascularized grafting cannot provide cure in the event of advanced osteoarthrtic degeneration. Correction of DISI appears to be an indispensable element for the prevention of osteoarthritis. This technique should not be proposed for patients with a necrotic proximal pole, a vascularized graft would be preferable.

Adolescent↗
PubMed2003

[Extensor tendon rupture after dorsal surgery of the rheumatoid wrist: analysis of nine reviewed cases].

We led a retrospective study to determine the causes of the tendon ruptures post-operating in the surgery of the wrist rheumatoid dorsal and to estimate the clinical result. At follow-up, we measured the extension lag and the rolling-up of fingers by the distance palm-pulps. Nine patients were so revised in the average of 40 months, average age was of 50.7 years. The tendon ruptures arose in 3 months in 67% of the cases. Seven times, a procedure on the distal radio-ulnar joint had been necessary (5 Sauvé-Kapandji and 2 Darrach). Thirty tendons had been concerned in this study, that is 3.3 tendons on average (1-5). Two main causes were found: attrition on the stub ulnaire and great intra-tendinous synovitis (per operating observation). At the revision, the lag extension means was 23 degrees (0-40). Rolling-up of the long fingers was complete 4 times on 7. The best results were observed after tendinous grafting or index proprius transfer with a lateral suture. Tendinous adhesions had arisen 6 times and persisted still at 3 patients. Our study underlines the interest to stabilize the stub ulnaire to prevent the post-operating ruptures and proposes a transfer or a graft in front of tendons very weakened by the synovitis.

Adult↗
PubMed2003

[A 36 month prospective study of 12 plate osteosyntheses of distal radius fractures].

INTRODUCTION: We performed a prospective study of 12 intra-articular distal radial fractures. The fractures were treated with an anterior plate together with posterior pinning. The aim of the study was to examine whether it was technically feasible to fix such fractures using this technique and to assess the stability of the fixation at follow up. METHOD: Twelve articular fractures were included with a mean age of 47.1 years. All patients were followed up from first admission to the 36th postop month with clinical and radiological checks. RESULTS: At follow up, we found 8 good and excellent clinical results, 3 fair and 1 poor. The combination of an anterior plate with posterior pinning allowed a good initial reduction but could not protect from secondary displacement particularly in the presence of a comminuted metaphysal fracture. DISCUSSION: This procedure gave clinically satisfactory results but did not control ulnar variance. This procedure should be combined with bone grafting in complex metaphysal fractures and epiphysal screws should be used whenever possible.

Bone Nails↗
PubMed2000

Cardiac valve papillary fibroelastomas: clinical, histological and immunohistochemical studies and a physiopathogenic hypothesis.

BACKGROUND AND AIM OF THE STUDY: Cardiac papillary fibroelastoma (CPF) is a rare and histologically benign tumor, but may have a malignant propensity for life-threatening complications; thus, surgical removal is justified. Case histories were reviewed of four patients who underwent surgical management after diagnosis of CPF located on aortic (n = 2) or mitral (n = 2) valves. Our aim was to provide explanations for the clinical diversity of the lesions and, using histological and immunohistochemical methods, to hypothesize the genesis of these tumors. METHODS: Among four patients with a diagnosis of valvular CPF, two had previous and recent history of neurological embolic symptoms with small echographically located tumors attached to the ventricular side of aortic cusps. Two other patients (one with paroxysmal atrial fibrillation, one with no neurological or rhythmically related stroke) had CPFs located on the posterior or anterior mitral leaflets. RESULTS: Surgical excision was performed with a conservative valve-sparing approach. Histological and specific immunohistochemical (IHC) studies were conducted on all samples. The postoperative course was uneventful, and histological analysis confirmed the diagnosis of CPF with typical fronds characterized by three successive layers. In the first two patients there was correlation between neurological events and the presence of thrombus aggregated on the injured superficial endothelial layer. In the other patients, no endothelial damage or thrombus was found. IHC studies showed dysfunction of the superficial endothelium, a centrifugal mesenchymal cellular migration arising from the central layer to the superficial layer with differentiation steps, the presence of dendritic cells in the intermediate layer, and remnants of cytomegalovirus (CMV) in the intermediate layer. CONCLUSION: Despite their benign histological aspect, and independent of their size, CPFs justify surgical excision because of their high potential to systemic embolization. In most cases, valve sparing management is possible with no observed recurrence after complete excision. The presence of dendritic cells and CMV strongly suggests the possibility of a virus-induced tumor, therefore evoking the concept of a chronic form of viral endocarditis.

Adult↗
PubMed1998

Automatic adaptation of the basic pacing rate in response to minute ventilation. Chorum French Investigational Group.

Rate responsive pacing based on minute ventilation (VE) correlates highly with metabolic demand. This type of sensing also recognizes extended periods of rest. The Chorum pacemaker includes a rate responsive algorithm that modulates the basic rate according to phases of activity versus sleep. Forty-six patients (mean age 78 +/- 15), received a Chorum pacemaker for atrioventricular block in 17 cases, sick sinus syndrome in 25, and mixed disorders in 4. Holter monitoring was performed to analyze to heart rate and to examine the circadian adaptation of the minimal pacing rate. The mean basic rate was programmed at 63 +/- 5 beats/min, and the sleep rate at 52 +/- 4 beats/min. Seventeen patients had spontaneous heart rates consistently above the programmed basic rate, and 6 had sustained supraventricular tachyarrhythmias. One-half of the patients had periods of pacing at the programmed sleep rate. The mean diurnal pacing rate was 68 +/- 5 beats/min compared to a mean nocturnal rate of 60 +/- 4 beats/min (P < 0.0001). The average time spent at the basic rate was 37 +/- 30 min (0-110) during daytime (4%), versus 242 +/- 153 min (20-477) at night (45%, P < 0.0001). No adverse effect was observed in this patient population. VE allows a reliable detection of the sleeping periods as well as an adjustment of the basic rate in accordance. Caution is advised in cases of bradycardia dependent tachyarrhythmias.

Aged↗
PubMed1997

Value of automatic processing and reliability of stored data in an implanted pacemaker: initial results in 59 patients.

Stored data in implantable pacemakers have rarely been used as a diagnostic tool because of the complexity. Our group has developed software called AIDA, providing an automatic interpretation of data stored in memories of the Chorus (ELA medical) pacemaker. We compared the results of AIDA analysis to surface ECG Holter interpretation in 59 patients (age 75 +/- 9 years). In 33 cases, neither AIDA nor the Holter found any anomaly. Eleven patients demonstrated episodes of supraventricular tachycardia (SVT), confirmed by AIDA in ten patients; AIDA failure was due to nonsustained episodes of SVT not inducing mode switch. Loss of atrial sensing, pacemaker-mediated tachycardia, and ventricular extrasystoles were detected by AIDA in ten patients. Traditional Holter missed three cases. This initial study confirms that stored pacemaker data, automatically interpreted can provide reliable information over a 24-hour period.

Aged↗
PubMed1996

Mode switch despite undersensing of atrial fibrillation in DDD pacing.

UNLABELLED: Mode switching algorithms are commonly used to protect the ventricles against high rates induced by atrial tachycardia. In the case of atrial fibrillation (AF), the response of these algorithms depends on the quality of atrial sensing. The Chorum 7234 DDDR pacemaker uses a new mode switching algorithm, based on a statistical analysis of the atrial rhythm. It includes two criteria of diagnosis: "high" if more than 28 of 32 cycles are abnormally accelerated; and "low" if more than 36 of 64 cycles are abnormally accelerated. METHODS: From a taped database of electrophysiological studies, episodes of AF lasting more than 2 minutes were selected. A tape recorder replayed the atrial signals into an external Chorum device. Each episode was replayed eight times with a programmed atrial sensitivity increasing from 0.4-2.0 mV. For each criterion of diagnosis and each programmed sensitivity, the percentage of atrial sensing, the time to switching, and the mean ventricular rate were measured. Ten episodes of AF from 10 patients (9 men and 1 woman; ages 62 +/- 16 years) were included: 1.95 +/- 0.97 mV and 196 +/- 64 ms. The sensitivity of the algorithm to diagnose atrial tachycardia reached 100%, for an atrial sensitivity set between 0.4 and 1.0 mV. The mean percentages of atrial sensed events were 74% +/- 18% and 46% +/- 9% for the "high" and "low" criteria, respectively. The mean diagnostic times were 28 +/- 26 seconds and 68 +/- 27 seconds, respectively. Sensing of < 23% of AF events resulted in failure to diagnose the arrhythmias by both algorithms. In the event of diagnostic failure, the mean ventricular pacing rate was 79 +/- 9 ppm. CONCLUSION: Up to an atrial sensitivity of 1 mV, 100% of AF episodes were diagnosed. The Chorum mode switching algorithms are 100% reliable if > 45% of the AF waves are sensed. In the event of switching failure, the ventricle is protected by an average rate remaining below 80 ppm.

Acceleration↗
PubMed1995

Carotid sinus syndrome: acute hemodynamic evaluation of a dual chamber pacing mode.

Cardiac pacing is the treatment of choice in patients with carotid sinus syndrome (CSS). Three different pacing modes were tested in 20 patients (16 males, 4 females; mean age 75 +/- 9 years) with documented symptomatic CSS. Three carotid sinus massages (CSM) were performed in each supine patient successively paced in random order in: DDI--the reference pacing mode; DDD--automatic mode conversion (DDD/AMC) allowing automatic switching from AAI to DDD when AV block occurs; DDD/AMC plus atrial acceleration (DDD/AMC+acc); and OOO (CSM without pacing) to determine whether the vasodepressive effect was still present 10 minutes after the preceding CSM. Intraarterial blood pressure was continuously monitored. Results were expressed as the value of the mean systolic BP at T0 + 3 s + 6 s ... T0 + 30 s divided by the value of the mean systolic blood pressure prior to onset of CSM. The drop in arterial blood pressure was more severe in the DDI mode than in DDD/AMC (P < 0.001) and DDD/AMC+acc (P < 0.0001) in 20 patients. In the OOO mode, the drop in arterial blood pressure was most marked and greater than in the DDI mode (P < 0.0001). The average time between start of the CSM and onset of the drop in blood pressure was the same in the three dual chamber modes. We conclude that the DDD/AMC mode significantly improves the vasodepressor response to CSM compared to the DDI mode. There is a current trend favoring DDD/AMC+acc over DDD/AMC.

Aged↗
PubMed1994

A new pacing algorithm for overdrive suppression of atrial fibrillation. Chorus Multicentre Study Group.

Constant rapid pacing may suppress arrhythmias, but it is usually poorly tolerated in the long term. We report a pilot study of a new pacing algorithm for overdrive suppression of atrial premature complexes (APCs) and atrial fibrillation (AF), which prevents postextrasystolic pauses and varies the pacing rate in response to the frequency of APCs. The algorithm was tested in a multiple crossover study for 24 hours in dual chamber pacemakers implanted in 70 patients. Comparison was made on ambulatory recordings between the number of atrial arrhythmias commencing with the algorithm active and inactive. In all cases, the algorithm functioned as designed. No patient was aware of its operation, and no malignant arrhythmias were induced. The 36 recordings that showed atrial arrhythmia were included for analysis. The effects of the algorithm were: APCs (estimated from pacemaker statistics) reduced in 18 patients, increased in 8 (P = 0.02); atrial salvos reduced in 12, increased in 4 (P = 0.041); and AF reduced in 11, increased in 8 (P = NS). In all patients with frequent AF (> 5 episodes in total), fewer episodes occurred when the algorithm was active. We conclude that the algorithm is safe and well tolerated, reduces atrial ectopic activity, and may reduce the frequency of sustained atrial fibrillation.

Adult↗
PubMed1994

Four chamber pacing in dilated cardiomyopathy.

A 54-year-old man received a four chamber pacing system for severe congestive heart failure (NYHA functional Class IV). His ECG showed a left bundle branch block (200-msec QRS duration) with 200-msec PR interval, normal QRS axis, and 90-msec interatrial interval. An acute hemodynamic study with insertion of four temporary leads was performed prior to the implant, which demonstrated a significant increase in cardiac output and decrease of pulmonary capillary wedge pressure. A permanent pacemaker was implanted based on the encouraging results of the acute study. The right chamber leads were introduced by cephalic and subclavian approaches. The left atrium was paced with a coronary sinus lead, Medtronic SP 2188-58 model. An epicardial Medtronic 5071 lead was placed on the LV free wall. The four leads were connected to a standard bipolar DDD pacemaker, Chorus 6234. The two atrial leads were connected via a Y-connector to the atrial channel of the pacemaker with a bipolar pacing configuration. The two ventricular leads were connected in a similar fashion to the ventricular channel of the device. The right chamber leads were connected to the distal poles. The left chamber leads were connected to the proximal poles of the pacemaker. Six weeks later, the patient's clinical status improved markedly with a weight loss of 17 kg and disappearance of peripheral edema. His functional class was reduced to NYHA II. Four chamber pacing is technically feasible. In patients with evidence of interventricular dyssynchrony, this original pacing mode probably provides a mechanical activation sequence closer to the natural one.(ABSTRACT TRUNCATED AT 250 WORDS)

Bundle-Branch Block↗
PubMed1994

Diagnosis of atrial arrhythmias using the Holter function of a new DDD pacemaker.

UNLABELLED: The extension of random access memory now makes it possible to store electrocardiographic (ECG) information, referred to here as Holter function (HF), in the memories of new pacemakers, which can be used as diagnostic tools during long-term follow-up. This report describes our experience in 26 consecutive patients for whom the device was used to detect episodes of atrial arrhythmias (AA). An illustrative case is also presented to describe in detail the device's analytical method. RESULTS: Fourteen AA profiles were successfully recorded in 10 patients by the pacemaker HF and correlated with confirmatory simultaneous surface ECG tracings. Three additional profiles were recorded in three other patients without simultaneous ECG recordings. A diagnosis of AA is established when the following findings are combined: (1) in all cases a large number of short interatrial intervals (A INT); (2) in presence of AV block, interventricular intervals (V INT) stored between the lower programmed pacing rate and the upper rate limit or the fallback rate; (3) in absence of AV block, V INT stored between the basic rate and the AV node refractory period; (4) in case of fallback, (VVI function) no stored AV INT; and (5) in absence of fallback, great variability of AV INT (Wenckebach function). CONCLUSIONS: (1) Diagnoses of AA can be made with the pacemaker HF; (2) The homogeneity of the HF profiles makes them useful for long-term follow-up and will probably contribute and clarify the natural history of AA in DDD patients; (3) HF may also serve to monitor the safety and efficacy of antiarrhythmic drug therapy during long-term follow-up.

Aged↗
PubMed1994

[Technical problems posed by automatic treatment of arrhythmia by an implanted pacemaker].

The automatic treatment of arrhythmias by cardiac pacemakers requires a phase of recognition of the arrhythmia followed by its treatment. Different factors limit the analysis and recognition ranging from the quality of detection of spontaneous events to the recognition of the arrhythmias. Bipolar dual chamber pacing is essential: it allows minimisation of the detection of interference or cross talk between the atrial and ventricular chambers and better discrimination of episodes of rapid rhythm. The treatment algorithms are multiple, difficult to investigate in the laboratory, and their efficacy varies with the evolution of the pathology or with medical treatment. There is not a single response but a programme where the antitachycardia modes of pacing succeed one another until the reduction of the arrhythmia. This instability of treatment implies a capacity of memorization with a double objective: to authorize a posteriori diagnosis of the treated pathology and to analyse the evolution of the antitachycardia response. These diagnostic functions are also dependent on the quality of detection and pacing. The automaticity of the treatment, when essential, can only be envisaged in patients available for strict and regular clinical follow-up.

Arrhythmias, Cardiac↗
PubMed1992

Use of a new fallback function to prevent endless-loop tachycardias: first clinical results. The Investigators of the Multicenter Study.

The methods used for preventing endless-loop tachycardias (ELTs) most often consist of initiating a long postventricular atrial refractory period (PVARP) with the sensing of every event likely to induce ELTs, such as sensed premature ventricular contractions (PVCs). A new fallback function may be useful to prevent the initiation of ELTs. A window of atrial rate acceleration detection (WARAD) is initiated with the sensing of every sinus event and equals 75% of the preceding PP interval. If an atrial event is sensed during this period, as are premature atrial contractions (PACs), no atrioventricular (AV) delay is initiated, but an atrial pulse output is delivered and a subsequent 31-msec AV delay is started. Theoretically retrograde P waves are premature compared to sinus rhythm. They are therefore detected as PACs, and do not initiate AV delay, thus prohibiting the induction of ELTs. This function was tested in six patients, using external or implanted Chorus 2 pacemakers. Short PVARP (203 msec) and high atrial sensibility were programmed. Retrograde conduction was induced either by inefficient atrial pacing or a long programmed AV delay. Two different dual chamber settings were tested: dual chamber pacing with the fallback function On or Off. In every situation, the function proved effective in preventing ELTs: the number of tachycardia episodes went from 124 with the function programmed Off to 5 with the function programmed On for comparable durations. More than 75 ELTs effectively prevented by fallback have been recorded.

Aged↗
PubMed1990

A new algorithm to solve endless loop tachycardia in DDD pacing: a multi-center study of 91 patients.

ELTs (endless loop tachycardias) are a common occurrence associated with DDD pacing. In order to detect and treat ELTs, an innovative automatic pacemaker algorithm was devised and evaluated. The basic principle of the algorithm rests on the relative stability of the ventriculoatrial conduction time (VACT) during ELTs. ELTs are suspected when the VACT remains stable and adheres to certain programmable limits referred to as VACT stability (16 or 31 msec); it is confirmed when the VACT remains stable after a programmable shortening of the AV delay (AVD) value, referred to as AVD shortening (47 or 63 msec). Ninety-one patients, 54 males and 37 females, were implanted with such an algorithm-specific device between January 10 and September 9, 1989. The reasons for implantation were as follows: 55 patients were implanted for AV block, 31 for sinus node dysfunction, and 2 for carotid sinus syndrome. Pacing parameters were programmed to favor ELT initiation (long AVD, short postventricular atrial refractory period [PVARP] and high atrial sensitivity) followed by basic programming of the algorithm (VACT stability set at 16 msec and AVD shortening set at 47 msec. Once this was done, a 24-hour Holter recording was obtained. Eighty-eight patients were thus analyzed, three being excluded from the final report due to the poor quality of the Holter tracings. In 43.2% of the sampling (38 patients), multiple episodes of ELT were identified, exhibiting a mean rate of 120 beats/min. In 26 of 38 cases (68.4%), the rate of ELT was found to be slower than the upper rate limit (URL).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Endless-loop tachycardias: description and first clinical results of a new fully automatic protection algorithm.

Endless-loop tachycardia (ELT) is one of the most common pacemaker mediated tachycardia. An innovative ELT protection algorithm has proven to be clinically effective. A new improved version that will eliminate the need to program any parameter is now under clinical evaluation. Nine patients entered the study: six men and three women, aged 52 +/- 22 years. This automatic algorithm needs only 10 cycles to detect and confirm an ELT. Three hundred thirty-three ELTs lasting more than 9 cycles have been induced and analyzed. The total results are the following: mean duration: 6.7 sec +/- 3.1; mean ELT rate: 137 +/- 21.9 bpm, mean programmed upper rate limit (URL): 142.5 +/- 26.5 bpm (Only 70% of ELTs presented rates equal to programmed URL). (1) ELTs reduced by postventricular atrial refractory period (PVARP) extension on one cycle: 291 ELTs (87%). ELT rate: 128.5 +/- 18.2 bpm. (2) Retrograde block: algorithm operation may induce a retrograde block due to a short atrioventricular delay (AVD) applied during the confirmation phase to discriminate an ELT from a stable sinus rhythm. Thirty-two ELTs (10%) have been reduced and detected on a retrograde block occurrence. (3) Algorithm failure due to an unstable ventriculoatrial conduction time (VACT) even at fixed rate or to a retrograde Wenckebach behavior on AVD reduction during the confirmation phase. A total of 10 algorithms failed to detect or confirm an ELT have been recorded (3%). Mean duration: 8.2 +/- 4.2 sec, mean ELT rate: 148.9 +/- 14.3 bpm. This new fully automatic algorithm has reduced 97% of ELTs, including high rate episodes (100-175 bpm).(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗