Biomedical subjects

T Romo

Publications and source records attributed to T Romo.

At least 37 records · Page 2Linked to original sources

PubMed1997

Clinical and histologic behavior of exposed porous high-density polyethylene implants.

Reconstruction in the head and neck is difficult and often requires complex solutions to restore functional and aesthetic form. While autogenous tissue is preferred, many alloplasts have been investigated. These materials, however, are foreign bodies, and most alloplasts tolerate exposure and infection poorly. An alloplast's in vivo behavior is a function not only of its composition but also of its form and macrostructure, as well as the interaction at the host-implant interface. Porous high-density polyethylene is well tolerated by surrounding tissue, and its porous core is rapidly infiltrated by host tissue. In order to further investigate the response of porous high-density polyethylene under adverse conditions, we implanted three porous high-density polyethylene disks and one silicone disk underneath the dorsal skin in each of 12 rats. The implants were exposed at differing times after implantation. After 7 days, the exposed areas were either skin grafted or allowed to close by secondary intention. Silicone implants all tolerated exposure poorly. Porous high-density polyethylene implants exposed soon after implantation also tolerated exposure poorly; however, none of these extruded. Porous high-density polyethylene implants exposed after the host tissue had invaded the pores tolerated exposure well, healing either by secondary intention or by skin grafting. Porous high-density polyethylene is a safe and reliable material for use in aesthetic and functional reconstruction of the head and neck. Porous high-density polyethylene and possibly other porous alloplasts tolerate exposure well once host fibrovascular tissue has invaded the implant pores. Further investigation of differing clinical settings and implant behavior is currently in progress.

Animals↗

PubMed1997

Bronchial epithelium associated to lymphoid tissue does not selectively express vimentin.

The existence of a lymphoepithelium containing M cells in the bronchus-associated lymphoid tissue (BALT) of several species has repeatedly been questioned. In previous electron microscopical studies we failed to ultrastructurally identify these cells in the epithelium covering bronchial lymphoid tissue of adult rats. In the present study, we analyze immunohistochemically the expression of vimentin, an intermediate filament, reported to be a sensitive marker for rabbit M cells, in both BALT and Peyer's patches. Our results demonstrate, however, the absence of vimentin expression in the epithelium covering the bronchial lymphoid aggregates as well as in the lymphoepithelium of the Peyer's patches. On the contrary, both epithelia are strongly cytokeratin positive. Furthermore, numerous vimentin-positive lymphocytes appear in both lymphoid organs. Results are discussed from a view of the possible relationship between BALT and the so-called mucosae-associated lymphoid tissue (MALT).

Animals↗

PubMed1996

Prevention of earlobe keloid recurrence with postoperative corticosteroid injections versus radiation therapy: a randomized, prospective study and review of the literature.

BACKGROUND: Simple excision of earlobe keloids can result in recurrence rates approaching 80%. Many modalities have been suggested to reduce the risk of recurrence postoperatively, including intralesional steroids and radiotherapy. OBJECTIVE: In order to determine the most reliable method to prevent keloid recurrence, we have conducted the first randomized, prospective trial comparing corticosteroid injections versus radiation therapy. RESULTS: Thirty-one keloids were treated and followed for a minimum of 12.0 months. Two of 16 keloids (12.5%) recurred after surgery and radiation therapy, while 4 of 12 (33%) recurred after surgery and steroid injections. No alteration of skin pigmentation, wound dehiscence, chronic dermatitis, or neoplastic changes was observed in any patient in either group. Although a statistically significant difference was not observed, radiotherapy appeared to be more effective than steroid injections in preventing keloid recurrence. CONCLUSIONS: Radiotherapy is a simpler treatment modality with better patient compliance, and patients were much more likely to complete treatment than with corticosteroid injections. We believe that radiotherapy can play an important role in the prevention of earlobe keloid recurrences, and that with current techniques, complications can be minimized. Further randomized study with additional patients is needed to compare the effectiveness of corticosteroid injections and radiotherapy in preventing keloid recurrence.

Administration, Topical↗

PubMed1995

A sampling problem in molecular dynamics simulations of macromolecules.

Correlations in low-frequency atomic displacements predicted by molecular dynamics simulations on the order of 1 ns are undersampled for the time scales currently accessible by the technique. This is shown with three different representations of the fluctuations in a macromolecule: the reciprocal space of crystallography using diffuse x-ray scattering data, real three-dimensional Cartesian space using covariance matrices of the atomic displacements, and the 3N-dimensional configuration space of the protein using dimensionally reduced projections to visualize the extent to which phase space is sampled.

Computer Simulation↗

PubMed1995

Long-term nasal mucosal tissue expansion use in repair of large nasoseptal perforations.

Reperforation rates of large, surgically closed nasoseptal perforations remain unacceptably high (30% to 70%). With the advent of newer surgical techniques, including external decortication rhinoplasty and midface degloving, excellent exposure of the intranasal anatomy is afforded. The limiting factor of these approaches is the deficiency of local intranasal mucosal lining, which is used to close large septal perforations. The paucity of nasal mucosal lining results in excessive tension on the perforation closure suture line that leads to distal flap ischemia, anastomosis breakdown and, ultimately, reperforation of the septum. Alternatively, using intraoral mucosal flaps of sufficient length and width to close large perforations results in significant and unacceptable donor-site morbidity. We present our technique of harvesting additional local endonasal mucosa using long-term soft-tissue expanders. Long-term nasal mucosal expansion was used in the closure of large septal perforations in five patients. Complications included one case of expander exposure and the morbidity of prefacial expander injections. Total closure of all five septal perforations was documented at the 1-year postsurgical visit. Histologic and electron-microscopic examinations of the expanded nasal floor mucosa are presented.

Collagen↗

PubMed1995

Unilateral aural atresia in childhood: case selection and rehabilitation.

The classic management of children and adolescents with unilateral aural atresia, with or without microtia, is to assess audition, to exclude cholesteatoma formation both clinically and radiologically, to offer amplification in unilateral cases, and to consider surgical repair in bilateral cases. However, evidence indicates that children with unilateral hearing loss from any cause are at risk for delayed language development, attention deficit, and poor school performance. Favourable factors for reconstruction of hearing include a normal bone line with good word discrimination, a normal or recognizable auricle (microtia grade I or II), radiographic evidence of an air-containing middle ear cleft with an estimated volume close to the normal side, the presence of ossicles, the facial nerve running in its expected (though abnormal) course, and the absence of any syndrome affecting mid-face development or of any associated mandibular malformation. In unilateral pediatric cases, only minor auricular malformations (grades I and II) were considered for otologic repair. If microtia was more severe (grade III and IV), or if the child had any other mid-face or mandibular problem, otologic repair was delayed until these were corrected. In many cases, otologic repair was deferred throughout childhood. A summary of selection criteria, case examples, and outcomes of surgery will be presented. Carefully selected unilateral cases may be reconstructed during childhood. Unfavourable cases should be amplified or observed.

Adolescent↗

PubMed1994

Otoplasty using the postauricular skin flap technique.

OBJECTIVE: To evaluate the efficacy of the postauricular skin flap technique in otoplasty. DESIGN: We conducted a case series study of 25 patients who underwent bilateral otoplasty for prominent ears over a 4-year period. Follow-up ranged from 6 months to 4 years. SETTING: Academic tertiary care referral center. PATIENTS: Twenty-five patients with congenitally prominent bilateral ears, aged 5 to 38 years of age. INTERVENTION: Cartilage-sparing otoplasties were performed with access using the postauricular skin flap technique. The specifics of cartilage correction were determined by the surgeon based on the patients' anatomic deformity. OUTCOME MEASURE: Clinically noted aesthetic results, complications, and patient satisfaction. RESULTS: No complications, such as hypertrophic scarring, keloid formation, scar migration, ear deformity, or obliteration of the postauricular sulcus, were noted. Patient satisfaction with the procedure was generally high. CONCLUSION: We conclude that the postauricular skin flap approach to otoplasty is safe, provides excellent exposure, is amenable to most cartilage surgical techniques, and is a valuable addition to otoplasty techniques.

Adolescent↗

PubMed1992

Versatile use of skin expanders in facial plastic surgery.

Large soft-tissue resection defects of the face and scalp present an arduous technical problem for the facial plastic surgeon. Successfully matching tissue coverage with similar skin color and texture is usually limited by the amount of available local skin. Also, the need to limit distortion of fixed anatomic sites when harvesting local skin must be addressed. With the advent and utilization of soft-tissue expanders, the availability of local skin is increased and anatomic distortions are limited. This article describes the versatile use of skin expansion in facial plastic and reconstructive surgery. Expansion techniques include long-term expansion for scalp and cervicofacial defects. Acute intraoperative expansion techniques address repair of perioral, labial, and nasal mucosal lining defects. The success, limitations, and complications of these techniques are reviewed.

Adolescent↗

PubMed1992

Aesthetic reconstruction of the platyrrhine nose.

The platyrrhine nose is characterized by a hypoplastic nonprojected nasal tip, wide flaring alae, underdeveloped premaxilla, and lack of nasal dorsal support. Aesthetic nasal reconstruction is performed utilizing the external rhinoplasty technique. Precise placement of nasal augmentation grafts is facilitated by this technique. The harvesting and utilization of a large autogenous nasal fibrofatty graft for finesse dorsal contouring is described. Seventy-five patients underwent aesthetic reconstruction of the platyrrhine nose. Follow-up ranged from 2 to 7 years. No major complications, including extrusion or significant resorption of augmentation grafts, have been observed. Minor complications included notching of the transverse columella incision in 5% (4/75) of cases, observable suture tract marks along the alar closure incision in 4% (3/75) of cases, and alar incision granuloma in 1% (1/75). A modification of our technique, utilizing a two-layer tension-free closure of the columella and alar incisions, has alleviated these complications.

Asian People↗

PubMed1992

Nasal reconstruction using split calvarial grafts.

The reconstruction of nasal deformities after trauma or surgical procedures presents an arduous task for the reconstructive surgeon. The anatomic alteration of supporting cartilage and nasal bones, as well as scar formation, compound the difficult nature of this type of reconstruction. In the past, multiple autogenous and alloplastic implants have been used in nasal reconstruction. Autogenous implants include auricular and septal cartilage as well as rib and iliac crest bone grafts. Alloplastic materials include acrylic, supramid mesh, Gortex, and silicone rubber. Autogenous grafts have been shown to provide excellent long-term reliable results in nasal reconstruction. In our study, autogenous split calvarial bone grafts were used in the nasal reconstruction of 17 patients. Among the corrective procedures were dorsal augmentation for saddle-nose deformities, insertion of columella struts for nasal tip ptosis, and insertion of nasal battens for nasal valve collapse. Patient followup has been from 1 to 5 years, with no significant resorption noted during that time. Complications were limited to one seroma at the donor site before wound drains were routinely used. No major complications, including hematoma formation, CSF leak, or infection, have been observed.

Bone Transplantation↗

PubMed1988

Repair of nasal septal perforation utilizing the midface degloving technique.

A technique utilizing the midfacial degloving approach in the repair of nasal septal perforations in 24 patients is reported. The midface degloving approach was limited to patients with septal perforations greater than 3 cm and failed prior attempts at surgical closure. Bilateral posteriorly based unipedicled flaps were utilized in the septal closure. Complete closure was accomplished in 75% (18/24) of cases, with a follow-up of one to three years. Complications included reperforation in 25% (6/24) of cases and partial vestibular stenosis in 20% (5/24) of cases. A modification of our technique, relining the nasal floor with postauricular full-thickness skin grafts, has alleviated vestibular stenosis.

Evaluation Studies as Topic↗

PubMed1988

Mycobacterial cervical lymphadenitis: a persistent diagnostic problem.

The most common manifestation of mycobacterial infection encountered in otolaryngologic practice is cervical lymphadenitis. Mycobacterial cervical lymphadenitis, or scrofula, remains a diagnostic and therapeutic challenge because it mimics other pathologic processes, and because of the inconsistent reliability of physical and laboratory findings. Twenty-five cases of scrofula were treated at our institution from 1973 to 1986. Positive chest x-ray was exhibited by five (20%) patients. Histologic examination of the excisional biopsy was the most reliable test with 100% positive specimens. This study emphasizes the marked variability in clinical presentation of scrofula and the importance of surgical excisional biopsy for histologic diagnosis.

Adult↗

PubMed1987

First branchial cleft cysts: clinical update.

First branchial cleft cysts develop as a result of incomplete fusion of the cleft between the first and second branchial arches and give rise to two distinct anomalies, termed type I and type II anomalies. Type I anomalies are purely ectodermal while type II anomalies exhibit ectodermal and mesodermal elements. The type II anomaly incorporates some portion of the first and second arch as well as the cleft. Type I lesions are extremely rare. They appear histologically as cysts lined by squamous epithelium. Clinically, they present as a cystic mass or fistula posterior to the pinna and concha. The cyst is usually superior to the main trunk of the facial nerve and ends in a cul-de-sac on or near a bony plate at the level of the mesotympanum. Type II lesions are more numerous and represent a duplication of both membranous and cartilaginous portions of the external auditory canal. They contain skin as well as adnexal structures and cartilage and may be associated with the parotid gland. Most frequently they are associated with fistulae in the concha or external auditory canal as well as fistulous openings in the neck.

Adult↗

PubMed1985

Combined tracheoesophageal injuries.

From 1974 through 1984, 23 patients with combined tracheoesophageal injuries from penetrating wounds were treated. Physical examination, endoscopy, a barium swallow, or a combination of these techniques confirmed the diagnosis preoperatively in 19 patients. A variety of operative techniques were used, with 20 of 23 repairs involving some type of primary repair of the trachea and esophagus, such as side repair or end-to-end anastomosis, with or without a tracheostomy. Major complications occurred in 74 percent of the patients and included eight cases of pneumonia, eight esophageal leaks, six tracheoesophageal fistulas, five mediastinal abscesses, four wound infections, and two carotid artery blowouts. To decrease the number of complications, several refinements in operative technique have been suggested.

Adolescent↗

PubMed1985

Metastatic basal cell carcinoma of the head and neck.

Five new cases of metastatic basal cell carcinoma are presented to highlight the potential of this tumor to develop malignant metastases. Histologic criteria of the primary and metastatic site are presented along with a review of the pertinent world literature.

Adult↗

PubMedDate not supplied

Mucous cyst formation after rhinoplasty.

The development of a deforming nasal-dorsal mass after rhinoplasty is a very rare and, for the most part, an avoidable complication. The list of differential diagnoses for such a postoperative external nasal lesion ranges from simple soft tissue edema or hematoma, which is usually temporary, to more serious lesions, such as lipogranulomas, epidermoid inclusion cysts, tumefactive cartilage proliferation, and mucous cysts, which can cause permanent deformities. Although various nasal tumors, infections, and granulomatous diseases are not specifically related to surgery, they should also be considered.

Adult↗

PubMedDate not supplied

Modulation of tissue ingrowth into porous high-density polyethylene implants with basic fibroblast growth factor and autologous blood clot.

OBJECTIVE: To investigate the effect of direct application of biologic materials normally present in wounds (basic fibroblast growth factor [bFGF] and autologous blood clot [ABC]) to accelerate the bony and soft tissue ingrowth into porous high-density polyethylene implants. METHODS: We conducted a prospective, blinded animal histological study. Disks made of porous high-density polyethylene impregnated with bFGF or ABC were implanted into adult Sprague-Dawley rats in both subcutaneous and subperiosteal locations. Animals were killed and implants were harvested at 2, 4, and 10 weeks postimplantation and examined histologically for fibroblast invasion, collagen deposition, and inflammatory reaction.The results were compared with control (untreated) implants. RESULTS: As a group, the histological results showed significantly more fibroblasts within the ABC-treated implants than control implants or bFGF-treated implants. This difference in the number of fibroblasts between ABC-treated implants and bFGF-treated and control implants was also statistically significant 2 weeks after implantation. CONCLUSIONS: At the concentration of bFGF of 1 microg/10 microL, no acceleration of tissue ingrowth into porous high-density polyethylene implants was noted. However, when porous high-density polyethylene implants were treated with ABC, the implants were invaded to a greater degree by soft tissue, particularly in the early postoperative period (first 2 weeks). Bioactive substances associated with the coagulation and platelet cascades present in the ABC may be responsible for this accelerated incorporation of the porous implant and may have clinical implications. Arch Facial Plast Surg. 2000;2:27-33

Animals↗

PubMedDate not supplied

Autologous collagen dispersion (Autologen) as a dermal filler: clinical observations and histologic findings.

OBJECTIVE: To assess the histologic behavior and clinical efficacy of autologous collagen dispersion (Autologen) in augmenting human dermis. SUBJECTS: Adult patients of the Facial Plastic Surgery Clinic at The New York Eye and Ear Infirmary who were undergoing facial aesthetic surgery with skin excision. METHODS: Five patients were injected intradermally with Autologen in one postauricular area and bovine cross-linked collagen (Zyplast) on the contralateral side. Patients were examined clinically for signs of infection, skin necrosis, or implant rejection/allergy 2, 4, and 12 weeks postinjection. Impressions and photographs of all implant sites were taken at all follow-up visits. Biopsy specimens of each implant were taken 4 and 12 weeks after injection and examined histologically for signs of integration, rejection, and resorption. RESULTS: All implants were well tolerated. No identifiable differences were noted in the clinical persistence of Zyplast vs Autologen. Histologically, there was more variability in the degree of fibroblast infiltration of Autologen vs Zyplast deposits. CONCLUSIONS: Our trial suggests that autologous collagen dispersion may represent a viable alternative to bovine collagen. Clinical persistence and histologic behavior of Autologen appear to be at least as favorable as those of Zyplast, and Autologen obviates the need for allergy testing and eliminates the possibility of disease transmission. Arch Facial Plast Surg. 2000;2:48-52

Adult↗