Search PubMed⌕ Search

Biomedical subjects

M Revol

Publications and source records attributed to M Revol.

At least 37 records · Page 2Linked to original sources
PubMed2001

[A scanning electron microscopy study of the surface of porous-textured breast implants and their capsules. Description of the "velcro" effect of porous-textured breast prostheses].

The efficacy of breast prosthesis texturing in the prevention of capsular contracture has been established for about 20 years. This successful procedure has led to the development and marketing of a number of different models. In the present study, four porous-textured breast prostheses have been examined: the Arion monoblock implant, the CUI (McGahn), the Biocell (Mcgahn), and the Sebbin LS21. Scanning electron microscopic (SEM) investigation of the implant surfaces of the different prostheses was carried out on new samples received from the manufacturers. During a prospective study on eight patients, capsule samples corresponding to the four above-mentioned prostheses were taken to determine whether a secondary intervention was necessary for correction of asymmetry or malpositioning. These samples were analyzed by SEM to investigate whether there could be a correlation between prosthesis texturing and the aspect of the corresponding capsules. Significant ultrastructural differences were found between the various prostheses examined: the results showed that only the CUI and Biocell prostheses presented a mirror image of the capsule texturing, with a correspondence between the depressions on the prosthesis and the contacts on the capsule. This finding seems to be linked to the existence of a critical size for the pores that constitute the implant surface. This observation led to the hypothesis of an adhesive "velcro" effect between the prosthesis and its capsule. Although the latter may not be directly linked to the prevention of capsular contracture it can, however, have a major effect on implant stabilization in cases of primary breast reconstruction and in possible secondary adjustments of asymmetry and malpositioning.

Adult↗
PubMed2000

Kinematics of prehension and pointing movements in C6 quadriplegic patients.

AIMS: C6 quadriplegic patients lack voluntary control of their triceps muscle but can still perform reaching movements to grasp objects or point to targets. The present study documents the kinematic properties of reaching in these patients. MATERIALS AND METHODS: We investigated the kinematics of prehension and pointing movements in four quadriplegic patients and five control subjects. Prehension and pointing movements were recorded for each subject using various object positions (ie different directions and distances from the subject). The 3D motion was analyzed with Fastrack Polhemus sensors. RESULTS: During prehension tasks the velocity profile of control subjects showed two peaks (go and return); the first velocity peak was scaled to the distance of the object. In quadriplegic patients there was a third intermediary peak corresponding to the grasping of the object. The amplitude of the first peak was slightly smaller than in control subjects. Velocity was scaled to the distance of the object, but with a greater dispersion than in control subjects. Total movement time was longer in quadriplegics because of the prolonged grasping phase. There were few differences in the pointing movements of normal and quadriplegic subjects. The scapula contributed more to the reaching phase of both movements in quadriplegic patients. CONCLUSION: In spite of some quantitative differences, the kinematics of the hand during reaching and pointing in quadriplegic patients are surprisingly similar to those of control subjects. Spinal Cord (2000) 38, 354 - 362.

Adult↗
PubMed2000

Quantitative and kinetic evolution of wound healing through image analysis.

To define a healing function based on parameters measured on digitized images of wounds, and to use it to compare the rate of healing of two skin graft donor sites, one treated with petrolatum gauze (Pg) and the other with a topical preparation containing alginates (A). Digital photographs of donor sites (depth 0.6 mm) taken every two days between day 6 and day 12 were analyzed blind using the same algorithm, following changes in color and homogeneity. Analysis of variance was used to identify those parameters that changed during healing. The healing function was constructed using measurements made in six patients (group 1) randomly chosen from ten requiring skin grafts, and was applied and validated using data from the remaining four patients (group 2). The results given by this healing function were compared with those provided by principal component analysis. The most significant healing parameters were those measuring wound homogeneity, and our healing function reflects how these change with time. The time-dependent curves of the function calculated for groups 1 and 2 matched well enough to be considered as being derived from the same set of measurements. The results given by this healing function explained, by analogy, the meaning of the first principal component of principal component analysis. From day 6 to day 12, the healing function followed the same time-course for the Pg and A treatments, but healing was achieved significantly earlier (4 days, p < 0.03) with A. This suggests that the effect of A on wound healing is achieved in the first six days, before the visual changes from epidermalization are analyzable.

Administration, Topical↗
PubMed2000

[The second chart. A retrospective critical analysis of hospital stays of long duration in a public plastic surgery department].

A nine-month retrospective survey related to the long-duration hospital stays was carried out in our plastic surgery department. Twenty five patients were concerned by a more than 21 days hospitalization, the sum of which reached 1,098 days. These figures corresponded to 1.4% of the patients and 14.5% of the hospitalization days. A critical analysis was based on four principles: 1--a plastic surgery department is exclusively devoted to plastic surgery, 2--nursing cares required by the healing of a soft tissues defect don't usually need hospitalization, 3--even if it has a wide surface and/or if it is located on the lower limbs, a skin graft doesn't usually require more than ten days of hospitalization, 4--without complications, a free tissue transfer doesn't usually require more than 15 days of hospitalization. Application of these principles showed that 633 days (58%) could have been theoretically spared. Consequently, it could have permitted to treat a greater number of patients. The cause of delaying patient exit was related to the surgeon in all but one cases. It was associated in 16% of cases with a bed shortage in the convalescent or nursing homes. As hospitalization durations longer than 25 days seemed unwarranted to the authors even in the most complex cases, they suggest a simple way to alert surgeons of their department to the long-duration stays. As the department patient's chart represents 13 days of hospitalization, they ask surgeons make a decision upon planning the exiting of patients before adding a second chart.

Adult↗
PubMed2000

[Isokinetic dynamometric evaluation of rehabilitation results of elbow extension in tetraplegic patients].

The authors designed a protocol to assess isokinetic muscle strength of elbow in tetraplegic patients after rehabilitation of elbow extension. Twenty-seven elbows from 16 patients were assessed, after deltoïd-to-triceps (10 cases) or biceps to triceps transfer (17 cases); the mean follow-up was 39 months. Seventeen elbows from 9 healthy individuals were also assessed. Regardless of the type of the transfer performed, the extension torque was on average much lower in the group of tetraplegic patients than in the control group, especially at the beginning of the movement. However the dynamic appearance of the curve of torque in extension was similar in the two groups. The mean flexion torque was on average very low after biceps-to-triceps transfer, especially at the end of the movement, but remained acceptable after deltoïd-to-triceps transfer.

Adult↗
PubMed2000

[Effect of brachial-radial and extensor carpi radialis longus tenodesis on elbow flexion-extension movements. Application to tendon transfers in tetraplegia].

The authors show that extension of the elbow produces a traction on brachioradialis (BR) and extensor carpi radialis longus (ECRL): if their tendon is distally freed, it is pulled in the proximal direction when the elbow extends. This phenomenon provides tenodesis effects, especially after tendon transfer in tetraplegia. It has been assessed on 31 upper limbs of patients and fresh cadavers. The mean tendon excursion, between 90 degrees flexion and full extension of the elbow, was 32 mm for BR and 19 mm for ECRL. These tenodesis effects related to the extension of the elbow leads the authors to recommend three practices in tetraplegic patients: active extension of the elbow should be restored before rehabilitation of the hand, and a 90 degrees flexion of the elbow is the position in which BR and ECRL transfers should be set intraoperatively, as well as immobilized postoperatively.

Biomechanical Phenomena↗
PubMed1999

Biceps-to-triceps transfer in tetraplegia. The medial route.

Eight tetraplegic patients (13 elbows) were treated by biceps-to-triceps transfer. To avoid the risk of radial nerve injury, we chose a medial routing of the biceps. The mean follow-up after surgery was 17.8 months (range, 4-47 months). No complications were encountered. Active extension of the elbow was achieved in each case. The mean postoperative active range of motion of the elbow was 6 degrees extension and 137 degrees flexion. After the biceps-to-triceps transfer mean extension torque of the elbow was 3.7 Nm and mean flexion torque was 10 Nm. In eight elbows in which it was measured, there was a 47% reduction in elbow flexion power. Nevertheless no patient complained about that reduction, and all of them were satisfied.

Adult↗
PubMed1999

Development of metastases in malignant melanoma is associated with an increase in the plasma L-dopa/L-tyrosine ratio.

In this prospective study we evaluated a new biochemical approach in which the plasma ratio of the melanin precursors L-dopa and L-tyrosine serves as a marker of metastatic dissemination in malignant melanoma. Control values (11.20 x 10(-5) +/- 2.92 x 10(-5)) were determined. The L-dopa/L-tyrosine ratio was evaluated in the plasma of 90 patients with malignant melanoma (stage I/II, n = 33; stage III, n = 33; stage IV, n = 24) classified according to the tumour/node/metastasis (pTNM) classification. A total of 106 samples were studied. Serial measurements were performed in eight stage III-IV patients. The L-dopa/L-tyrosine ratio was significantly elevated in melanoma patients with clinical stage III (15.23 x 10(-5) +/- 3.34 x 10(-5)) compared with stage I (10.88 x 10(-5) +/- 2.52 x 10(-5)). Stage IV patients showed a significant increase in the plasma L-dopa/L-tyrosine ratio (45.73 x 10(-5) +/- 61.75 x 10(-5)) compared with the other groups. The ratio was higher for those with two rather than one metastatic site and markedly higher for those with widespread metastases. The development of metastases was associated with an increase in plasma L-dopa, a decrease in plasma L-tyrosine and a significant increase in the plasma L-dopa/L-tyrosine ratio. These data suggest that the plasma L-dopa/L-tyrosine ratio reflects the tumour burden and correlates with the progression of malignant melanoma.

Adult↗
PubMed1999

[Latissimus dorsi free flap with "Y" anastomoses. Technical variant and use in leg reconstruction].

The authors report a new technique for harvesting and anastomosis of the latissimus dorsi free flap. The latissimus dorsi free flap is elevated with the subscapular and circumflex scapular vessels forming a "Y" pedicle. The recipient artery is sectioned and the arterial tree of the flap is anastomosed to the recipient vessel by two end-to-end anastomoses. This technique is particularly useful in leg reconstructive surgery when only one vessel remains: it simplifies transfer (end-to-end anastomosis), anastomoses are easier because more superficial.

Adult↗
PubMed1999

[Breast reconstruction by inflatable anatomical implant. Retrospective study of 65 cases].

This study reports the first mammary reconstruction series with anatomic saline implants after mastectomy for breast cancer. 65 patients were reviewed with a 10-month follow-up. The authors used Mac Gahn anatomic saline implant style 468 or 363. The contralateral breast mammaplasty for symmetrisation was performed in 53 patients, usually during implantation of the implant. The nipple areola reconstruction was usually performed with full thickness' skin graft and Little's flap. The implants, (average volume of 275 ml before changing), were changed for 17 patients, because of insufficient reconstruction or an excessively high mammary fold. The most frequent complication was pain, despite morphine protocols (19 patients). These were a cases of 9 rippling; but only a small percentage of internal dimple (4 patients). Patient and surgeon satisfaction was rated (1-20) and classified into three levels. In conclusion, the advantages of anatomic saline implants are: to avoid some symmetrisations, reconstruction of a stable breast, to avoid internal dimple. The disadvantages are: persistent rippling, specific learning for their implantation and difficulty of the choice of size.

Adult↗
PubMed1999

[Evaluation of a two-stage surgical strategy for the treatment of skin carcinomas. Retrospective study of 367 cases].

The treatment of skin carcinomas in France is mainly based on surgical resection. However, when the cutaneous surgical defect cannot be sutured, repair by skin graft or skin flap can be either immediate or delayed. The aim of the present study is to evaluate the value of delayed repair. A six-month retrospective study was designed between November 1997 and April 1998, on a total of 367 resections of skin carcinomas and/or premalignant lesions. Two parameters were recorded: management of the skin defect, and the histological results. Out of the 367 resections, there were 275 resections with suture, 42 resections with skin graft, 11 resections with skin flap, and 39 resections without wound closure. In 41 cases further re-excisions were performed because the tumors were incompletely excised. Incompletely excised tumors were found in 6% of sutures, 9% of skin flaps, 24% of skin grafts, and 36% of delayed repairs. The high rate of incomplete surgical resections supports two-step surgery without wound closure when the defect cannot be sutured. This attitude is reinforced by the difficulty of the re-excision when a skin graft or a skin flap has been previously performed.

Basal Cell Carcinoma↗
PubMed1999

[Surgical repair of abdominal wall].

Surgical repair of abdominal wall defects following tumour resection only raises real problems when the nature of the tumour required wide, or even transfixing excision, as in the case of sarcomas or very advanced carcinomas. Superficial repair is performed according to the algorithm of the simplest technique: secondary healing, partial suture, total suture, transplant, or flap (pedicled or free). In the case of transfixing resection, the combination of a biomaterial for reconstruction of the deep plane and a superficial flap is necessary. For very large transfixing defects of the abdomen, a free flap may be required and, in this case, delayed insertion after initial transfer may further reduce the operative risk ("apple turnover" technique). The complications observed in a detailed series of 9 cases operated at Saint-Louis Hospital consisted of one intraoperative cardio-circulatory arrest during second-stage surgery and one late infection at three years. The authors believe that the indications for delayed insertion of a free flap are still very topical in cases in which a very large grafted free flap is necessary in conjunction with a prosthesis. Large abdominal defects after cancer resection can be reconstructed by modern reconstructive surgery.

Abdominal Muscles↗
PubMed1999

[Malignant tumors of the abdominal wall. 10 years of experience at the Saint-Louis Hospital].

The authors present a 10-year retrospective study of 52 patients with dermatofibrosarcomas (33 cases), sarcomas (13 cases) and desmoid tumours (6 cases) operated in their department. All these tumours were located in the abdomen or adjacent regions. Resection margins were 5 cm for dermatofibrosarcomas and 2 cm for sarcomas and desmoid tumours, with a healthy deep anatomical barrier. Dermatofibrosarcomas were repaired by direct suture in 18% of cases, directed healing in 15%, healing and graft in 45% and flap in 31% of cases. 61% of sarcomas were sutured directly, 7% were treated by directed healing and 23% required cover by a flap. All desmoid tumours were closed by primary suture. The quality of the first surgical resection remains the predominant prognostic factor.

Abdominal Neoplasms↗
PubMed1999

[Main abdominal flap donor sites].

The main flaps derived from the abdominal wall are described, indicating the following points for each one: vascular anatomy, the cutaneous and/or muscle territory of the flap, the arc of rotation, the main applications and finally comments concerning certain specific anatomical or technical points. Rectus abdominis flaps are by far the most frequently used in routine clinical practice for mammary reconstruction and cover of the thorax, abdomen or groin areas. Groin flaps are also frequently used, either as pedicled flaps to cover defects of the upper extremity or abdomen, or as free flaps, especially for mandibular reconstructions.

Abdominal Muscles↗
PubMed1999

[Anatomical study of the distal tendon of the brachial biceps muscle. Application to biceps-triceps transfer in tetraplegic patients].

In some cases of biceps-to-triceps transfer the muscle fibres of the biceps are inserted very distally, preventing correct setting of the transfer. A knowledge of the anatomy of the intramuscular part of the distal tendon of the biceps is useful to lengthen this tendon proximally. A study of 40 specimens showed that the intramuscular part of the distal tendon of the biceps is a large flattened lozenge-shaped aponeurosis located in a frontal plane. It receives muscle fibre insertions on both aspects. The length of the invisible part of the tendon can be estimated by a simple formula: 0.55 a + 4 cm, where "a" represents the length of the tendon between the most proximal tendinous point visible, and the most distal muscle point visible.

Cadaver↗
PubMed1998

[Method of esthetic evaluation of the reconstructed breast after cancer. Report of 76 cases].

The authors propose a simple method of aesthetic evaluation of breast reconstructions after cancer, based on a 20-point score. In the 76 patients included in this study and mainly reconstructed by implant, the following seven criteria were evaluated by a score: the reconstructed breast, the symmetrized breast, symmetry of the 2 breasts, the areola, the nipple, the areolo-nipple complex (ANC) and the overall reconstruction. The first score was established during the visit by the patient and independently by the same plastic surgeon. The score was then established during two sessions of projection of standardized photographs, by two groups, A and B, composed of 9 nurses and secretaries and 10 plastic surgeons, respectively. Statistical analysis of the results showed that the scores for these criteria were all correlated for all examiners. This study confirms the reliability of aesthetic evaluation of breast reconstruction after cancer, by a group composed of 2 men and 2 women, surgeons or non-surgeons, on photographs or on clinical examination, based on a 20-point score.

Breast Neoplasms↗
PubMed1998

[VCS microclip anastomosis on blood vessels of less than 2 millimeters in diameter. Preliminary experimental study in the rat].

The aim of this work was to study the possibilities and limits of the vascular microanastomoses with VCS microclips. VCS Microclips are a new mechanical anastomotic device, allowing a single operator to perform anastomoses without microsutures. The two arcuate limbs of the titanium microclips do not penetrate the vascular intima. The microclip anastomosis technique is based on symmetric eversion of the vessel walls, facilitated by everting forceps. We studied the medium and small Autosuture VCS microclips on different vessels ranging from 0.3 to 2 millimeters in diameter: aorta, carotid artery, femoral artery and femoral vein. Thirty nine end-to-end or end-to-side anastomoses were performed on Wistar rats. These anastomoses were performed by a single operator without the use of sutures. Patency was studied by the "empty and refill" test immediately and at two months. Histologic analysis of the anastomosis was performed at two months (hematein-eosin and orcein stains on longitudinal sections). Four out of thirty nine anastomoses were occluded during the 15 minutes following clamp release. Failure was always due to a technical error and occurred during the first trials. The thirty five other anastomoses were patent immediately and at two months post-operatively, except for the by-pass which was not viable. These anastomoses were still patent 30 minutes post-operatively. Light microscopy analysis confirmed that the microclip extremities did not penetrate the lumen, although the internal media was usually very thin at the level of the microclip jaws, especially for the smallest vessels. For vessels larger than 1 mm in diameter, the microclip extremities were usually outside the internal elastic lamina. No anastomotic aneurysm was found. Vascular healing was comparable with microsutures at 2 months. Microvascular anastomoses performed with microclips have numerous advantages, compared to usual microsutures: they are two to three times quicker, they can be performed step by step without turning the clamp and they can be performed with the right or left hand. There is theoretically no thrombogenic risk. The drawbacks are the need for complementary training and the cost of microclips which is five to six times that of sutures. End-to-side anastomoses of small vessels are more difficult than end-to-end anastomoses. The recipient vessels must be larger than 1.5 mm in diameter, otherwise the anastomosis may become stenosed. Microclips are especially useful to save time, i.e. for multiple anastomoses and for anastomoses of vessels larger than 1 millimeter in diameter. Some modifications of the material could allow vascular or hollow organ anastomoses with endoscopic assistance.

Anastomosis, Surgical↗