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Biomedical subjects

J M Serra

Publications and source records attributed to J M Serra.

At least 19 recordsLinked to original sources
PubMed2005

[Complications of craniofacial resection in anterior skull base tumors].

INTRODUCTION: The development of new radiographic techniques and the refinement of microsurgery and reconstructive surgery have been the responsible of the establishment of craniofacial resection (CFR) as the standard treatment of anterior skull base tumors. Overall complication rates varies from 24-56%, according to a review of recently published series. OBJECTIVES: To describe the complications of CFR in a series of 41 patients and to analyze the management and final outcome. MATERIAL AND METHODS: From 1990 to 2002, 41 patients underwent CFR for tumors involving the anterior cranial base. The extent of the tumor was always assessed with craniofacial CT-scan and MRI. The objective of the surgical treatment was to achieve "on block" removal of the tumor. RESULTS: The average age was 57 years with a male preponderance (63.4%). Squamous cell carcinoma was the most frequent histopathological type of tumor. The tumors were localized in paranasal sinuses in 78% of the cases. Bifrontal craniotomy was performed in 85.4% and unilateral orbitofrontal craniotomy in 14.6% of the cases. The area of facial resection included: ethmoidectomy (60.9%), ethmoido-sphenoidectomy (24.3%), maxillectomy (39%) and orbital exenteration (14.6%). The reconstruction of the floor of the anterior cranial fossa was performed using pedicled pericranial flap (100%), local (34.1%) or microvascular free flaps (21.9%) and split calvarian graft (19.5%). 20 patients (48.7%) developed post-operative complications, CSF leaks (12.1%) and meningitis (7.3%) being the most frequent major complications. The mortality rate was 7.3%. CONCLUSIONS: CFR has become the standard approach for anterior cranial base tumors. Despite its widespread application, the complication's rate ranges between 24-50% and the procedure carries a risk of significant morbidity and even mortality. Improvement of specific aspects of surgical technique and more refined reconstructive methods will decrease the number of complications.

Adolescent↗
PubMed2000

Is the reversed fourth dorsal metacarpal flap reliable?

We have carried out a study to determine if a flap based on vessels in the fourth metacarpal space could be used safely. We studied ten fresh cadaver specimens and used the flap in nine patients. In the anatomical study, we confirmed the presence of a suitable artery in nine out of the ten hands, arising from a piercing artery at the metacarpal bases, running distally under the fascia. The pivot point is located at the metacarpal heads, where the artery anastomoses to palmar branches and dorsal digital branches. In the clinical setting, the flap was reliable in eight patients. There was one case of flap necrosis. The flap seems to be reliable but several technical points are stressed to avoid complications.

Cadaver↗
PubMed1999

Relationship between flow and incidence of thrombosis in polytetrafluoroethylene vascular grafts in free microvascular flaps in lambs.

We have done an experimental study in lambs in which we investigated the influence of flow rate on free microvascular flaps using polytetrafluoroethylene (PTFE) vascular grafts. We set up five surgical groups in which blood flow was progressively increased through the PTFE vascular graft. In group I (venous autograft) we observed just one vascular thrombosis which was located at the site of the anastomosis. In group II (PTFE 3 x 10 mm) all the microvascular flaps became necrosed after the third postoperative day. In group III (PTFE 3 x 10 mm) necrosis also developed in all cases, but the anastomoses remained permeable no longer than eight days. In group IV (3 x 15 mm) the permeability in the microvascular free flaps was about 40% after 21 days, and in group V (3 x 10 mm) it reached 70%. To match graft flow rates with flap survival we did a regression analysis of flow rates for groups II, III, and V and the corresponding survival periods for the flaps. There was a clear and highly significant relationship (r = 0.717, p = 0.0001). In conclusion, it is necessary to maintain blood flow through the prosthesis at a rate higher than the thrombogenic threshold. When the flow rate in the vessels through the PTFE grafts was higher, the viability of the flaps was better. The ideal surgical technique should always be based on an arteriovenous fistula distal to the PTFE vascular graft. It is necessary to maintain blood flow through a prosthesis at a rate higher than the thrombogenic threshold.

Animals↗
PubMed1999

Primary amyloidosis presenting as extensor tenosynovitis.

Primary amyloidosis is a systemic disease. Amyloid arthropathy is an invalidating and uncommon form of presentation, but tenosynovitis is even rarer as the first sign of the disease. We report herein a case of unilateral amyloid deposit in the synovium of the extensor tendons of the hand, which was the first manifestation of a primary amyloidosis.

Aged↗
PubMed1998

Reconstruction of pharyngostomes with a modified deltopectoral flap combining endoscopy and tissue expansion.

The problem of pharyngostomic closure is difficult to solve, as evidenced by the large number of techniques described. The authors present the reconstruction of pharyngostomes by using Bakamjian's deltopectoral flap modified by the use of endoscopically introduced expanders for those patients in whom other techniques of choice (such as vascularized free flaps) have failed or are inapplicable either because of previous radiotherapy or because of local conditions. Bakamjian's deltopectoral flap, previously expanded with an expander coated with a partial-thickness skin graft and introduced endoscopically, allowed the authors to lift the flap in one operation to close the pharyngostome. This method provides the two walls of the pharynx (the skin graft as the inner aspect and the skin flap as the outer aspect), and the donor deltopectoral area is covered and epithelialized due to the skin graft. Thus by means of endoscopic expansion we use a nonaggressive technique to increase the surface area of the donor site and to increase its vascularization (delay phenomenon). Because the expander was coated with the graft, the authors were able to cover the anterior wall of the pharyngostome and the donor site in one surgical step.

Aged↗
PubMed1998

Transconjunctival herniation of orbital fat.

The authors present 3 patients with subconjunctival fat prolapse treated at their oculoplastic unit. Albeit rare, orbital fat is a well-recognized entity, and is described in the literature as being associated with trauma and surgery. The 3 patients reported herein, however, presented with no history of trauma or surgery. This condition is produced by herniation of the intraconal fat between the conjunctiva and the sclera, presumably due to dehiscence of the Tenon's capsule. Differential diagnosis should be made with lacrimal gland ptosis, lacrimal gland tumors, and lymphoid tumors.

Adipose Tissue↗
PubMed1997

Effects of involuntary auditory attention on visual task performance and brain activity.

Involuntary attention to auditory stimulus changes during a visual discrimination task was studied with event-related potentials (ERPs) recorded from the human scalp. A repetitive standard tone or an infrequent, slightly higher deviant tone preceded each visual target stimulus. Deviant tones elicited the mismatch negativity and P3a ERP components and caused increases in reaction time and error rate in the visual task indicating involuntary attention to an auditory stimulus change. These effects were observed even when the tones occurred simultaneously with a visual warning stimulus introduced to keep attention focused on the visual task. In the latter condition, involuntary switching of attention away from the visual task also attenuated the N1 ERP component to visual target stimuli preceded by the deviant tone.

Acoustic Stimulation↗
PubMed1997

Vascular cryopreservation in microsurgery.

Cyropreservation of blood vessels has been carried out for some decades with variable results. A rabbit model was used to compare cryopreserved femoral artery allografts (n = 12 arteries), fresh autografts (n = 15 arteries), and fresh allografts (n = 16 arteries) at 1 and 3 months postoperatively. Patency rates were highest in the fresh autografts (86.7 percent), followed by the cryopreserved allografts (66.7 percent at 1 month and 83.3 percent at 3 months) and fresh allografts (62.5 percent at 1 month and 75 percent at 3 months). The fresh allografts showed the greatest alterations in endothelial cells and intima and muscle layer, followed by cryopreserved allografts, and then fresh autografts. Changes observed included pseudoendothelium formation, thickened intima, and thinner muscle layer. Cellular infiltrate appeared on the vessel walls only in the cryopreserved allografts (25 percent), but this did not have an effect on vascular patency. Fresh autografts remain the graft of choice for vascular defects, but cryopreserved allografts serve as the most appropriate option when the former are unavailable.

Animals↗
PubMed1997

Tissue expansion with endoscopy.

Tissue expansion is a time-honored technique in plastic surgery. However, while it is possible to rectify quite severe problems, the technique is not free of complications (e.g., extrusion) and, moreover, it can be a lengthy procedure, often taking months. Endoscopy is increasingly being used in plastic surgery and has the advantage that large areas can be dissected using only small incisions. However, in endoscopic plastic surgery the main problem is the lack of an optical cavity. This means that special retractors are needed to keep skin and fat tissue lifted. This paper describes a technique for the placement of tissue expanders during endoscopy. Incisions are not made in the area that is to be expanded and, thus, there is no risk of extrusion and tissue expanders can be fully inflated intraoperatively. A further advantage is that the procedure reduces patient discomfort to a minimum.

Adult↗
PubMed1997

Carpal tunnel release with short incision.

A new approach for carpal tunnel release is presented. By means of a specially designed guide, it is possible to completely section the carpal ligament with a short incision without damaging the carpal contents. When the retinaculum has been sectioned and the guide removed by means of three Senn-Miller retractors, one proximally and two laterally, the median nerve is seen perfectly. We performed an anatomic study to determine where the incision should be made to avoid injuring the vascular arch, the cutaneous palmar branch of the median nerve, and the ulnar nerve. We present the results obtained in 112 patients followed up for 1 year. Complaints about tenderness of the scar disappeared, and by the end of the study, patients had regained 126 percent of their preoperative grip strength. All patients were able to use their hands shortly after the operation, and after 3 weeks, all of them returned to work. We think that by using this approach we combine the advantages of the "endoscopic" technique (minimal scar, no tenderness, and early recovery) with those of the classic open technique (exploration of the carpal contents).

Adult↗
PubMed1997

Retractor with mobile endoscope.

I have designed two retractors with mobile endoscopes that allow an assistant to lift up the flap and the endoscope. By doing this, the assistant maintains the optical cavity open while the surgeon dissects. There are two models, one with 180-degree lateral swing and the other with motion in all directions (vertical and lateral).

Endoscopes↗
PubMed1996

The H1-receptor antagonist chlorpheniramine decreases the ending phase of the mismatch negativity of the human auditory event-related potentials.

Auditory event-related potentials (ERPs) were recorded in 20 healthy male humans, who received either a single 4 mg dose of d-chlorpheniramine or a placebo, according to a double-blind design. Subjects were instructed to read a book and to ignore random sequences of 90% standard (1000 Hz) and 10% deviant (1100 Hz) tones, presented with stimulus-onset asynchrony (SOA) of 480 ms. Deviant tones elicited the mismatch negativity (MMN) response, which was smaller at its ending phase in the chlorpheniramine group. The auditory exogenous components (N1 and P2) were similar in both groups. Results demonstrate that the antihistamine chlorpheniramine selectively affects the automatic stimulus-change detector associated with MMN, and suggest an involvement of the histamine H1-receptor in the genesis of the MMN.

Acoustic Stimulation↗
PubMed1993

Surgical treatment for congenital absence of the vagina using tissue expansion.

A modification of the Abbe-McIndoe technique for the treatment of congenital absence of the vagina, using a cylindrical tissue expander wrapped in a mesh split-thickness skin graft, instead of a rigid silicone mold, is presented. The expander was kept in place for a period of two to six months and the functional result was 100 percent in all the six patients treated. Our experience led us to change the design of the expander (cylindrical, without ring, 10X4 centimeters) and to place the valve in the inner thigh as the best site for the valve. The age range of the patients was 18 to 27 years, and the final result was good or very good in five of the six women. Only one patient has occasional dyspareunia, which does not prevent sexual intercourse.

Adolescent↗
PubMed1992

Use of a calf prosthesis and tissue expansion in aesthetic reconstruction of the leg.

We present a technique for reconstruction of the legs in patients with soft-tissue loss and formation of large scars with retraction of this tissue in the pretibial region. In such patients, a subcutaneous tissue expander is placed in the region adjacent to the scar tissue. With expansion, we obtained sufficient skin for use in the reconstruction, and the resulting asymmetry in leg diameter was compensated for by means of one or two calf prostheses, depending on the patient.

Adult↗
PubMed1991

The vascularized fibula graft in mandibular reconstruction.

The use of a vascularized graft from the fibula for mandibular reconstruction is presented. The great strength, pliability, and long vascular pedicle that characterize such grafts make them particularly suitable for this type of repair. The results in six cases were highly satisfactory. Masticatory function was well restored, without alteration of the facial contour, and with minimal sequelae at the donor site.

Adult↗
PubMed1990

Simultaneous reconstruction of both feet with a vascularized latissimus dorsi free flap.

Simultaneous reconstruction of both feet with a single vascularized latissimus dorsi free flap is reported. The authors describe the repair of extensive dorsal and plantar defects, as well as of heel lesions secondary to osteitis of the calcanei. The latissimus dorsi free flap serves well in combining the classic cross-leg procedure with microsurgical techniques.

Adult↗