Biomedical subjects

J Nogueras

Publications and source records attributed to J Nogueras.

8 recordsLinked to original sources

PubMed2002

Growth of bioactive surfaces on dental implants.

Some metallic materials, such as pure titanium, Ti-6Al-4V, are used for dental and orthopedic implants under load-bearing conditions. However, they do not form a chemical bond with bone, which would achieve a good implant-bone fixation in service. In recent works, it has been demonstrated that an in vitro, chemically deposited, bone-like apatite layer with bone-bonding ability could be induced on a titanium surface. By reproducing that chemical procedure, in this work, a dense bone-like apatite layer was formed on the surface of the titanium in simulated body fluid. In addition, the different steps and kinetics of the layer-formation have been studied, because the observation of the samples in the wet state by means of the environmental scanning electron microscope has allowed the observation in situ of the apatite deposition process over a number of days. One of the most important features of the present study is that it can be carried out on a single titanium sample and the process is not interrupted at any stage. One of the main drawbacks of this chemical method is that the samples covered with apatite are susceptible to contamination by bacteria. The behavior of different types of antibiotics used to avoid this contamination has also been studied using the environmental scanning electron microscope. Finally, osteoblast cells have been cultured on the apatite-coated titanium samples to assess their biocompatibility.

Alloys↗

PubMed2000

Do prior abdominal operations alter the outcome of laparoscopically assisted right hemicolectomy?

BACKGROUND: Adhesions can increase the difficulty of both laparoscopic surgery and laparotomy. The aim of this study was to compare the results of laparoscopically assisted right hemicolectomy in patients after prior abdominal operations (PAOs) with the results in patients without prior abdominal operations (NPAOs). METHODS: Between August 1991 and September 1998, 85 patients underwent laparoscopically assisted right hemicolectomy. The Mann-Whitney test or Fisher's exact test was used for statistical analysis. RESULTS: In this study, 36 patients (21 women and 15 men), with an average age of 57.5 years (range, 15-87 years) had undergone a mean of 1.25 (range, 1 to 3) PAOs, whereas 49 patients (20 women and 29 men), with an average age of 60.0 years (range, 16 to 87 years) (p = 0.44) had undergone NPAOs. Overall in the PAO and NPAO groups, respectively, there were no significant differences in the incidence of intraoperative complications (3 versus 4; p = 1.0). The mean operative time was 151 min (range, 90 to 260 min) versus 148 min (range, 70 to 270 min) (p = 0.66), and the mean length of stay was 6. 8 days (range, 3 to 18 days) versus 7.6 days (range, 3 to 19 days) (p = 0.13). The procedure was converted to laparotomy (p = 0.754) for six patients in the PAO group (5 because of adhesions) and 6 patients in the NPAO-group (1 because of adhesions; p = 0.078). In the PAO group 17 patients (47%) had 22 postoperative complications: 11 general medical and 4 wound-related complications. Seven patients (19%) had prolonged postoperative ileus. In the NPAO-group 18 patients (38%) had a total of 22 complications: 7 general medical problems, 6 wound-related complications, and 8 prolonged postoperative ileus, none of which were statistically significant. One patient in the NPAO group had an anastomotic leak. During a mean follow-up period of 41 months (range, 3 to 89 months), three patients in the PAO group and four in the NPAO group developed incisional hernias. CONCLUSIONS: Although there is a trend toward more conversions because of adhesions in patients with a history of prior abdominal operations (p = 0.078), no increase in morbidity resulted. Therefore, laparoscopically assisted right hemicolectomy can be offered to patients with PAO, whose rate of adhesions can be expected to equal that of patients with NPAO.

Abdomen↗

PubMed2000

The use of rectal ultrasound for the correct diagnosis and treatment of rectal villous tumors.

BACKGROUND: One of the difficulties associated with surgery for rectal villous tumors (RVT) is the finding of invasive adenocarcinoma after transanal excision (TAE) and the possible need for more radical procedures or adjuvant therapy. Improved preoperative evaluation may eliminate this dilemma. The aim of our study was to evaluate the role of transrectal ultrasound (TRUS) in establishing the correct diagnosis of RVT. METHODS: All patients with biopsy proven RVT, who were referred for TAE, underwent preoperative TRUS in addition to the routine evaluation. If invasion beyond the submucosa was suspected by TRUS, multiple biopsies were taken before any surgical intervention in order to exclude invasive cancer. If no invasion was noted, biopsies were avoided and a TAE was performed. The final pathology results were compared with both the preoperative diagnosis and TRUS results. RESULTS: Thirty-five patients (19 female, 16 male; mean age 67.5 years, range 36 to 88) were studied. The mean distance of the distal extent of the lesion above the anal verge was 5.8 cm (1.5 to 6). In 27 patients, the tumor was limited to the submucosa (uT0, uT1) on TRUS and, therefore, TAE was performed. In 26 of 27 patients (96%), pathology examination confirmed the presence of RVT without evidence of malignancy. One patient was found to have invasion of the muscularis propria and required postoperative radiation therapy. In 8 patients (23%), TRUS showed extension beyond the submucosa; 3 of these patients had uT2 lesions, 4 had uT3 tumors, and 1 had perirectal nodes. These 8 patients underwent repeated biopsies with the finding of invasive adenocarcinoma in 7. Two patients underwent abdominoperineal resection, 3 had a low anterior resection, and 3 had a TAE. Final pathology confirmed the preoperative diagnosis of invasive adenocarcinoma in 7 patients. In the 1 patient with a uT2 lesion and negative biopsies, the final diagnosis was RVT with no evidence of malignancy. CONCLUSIONS: Preoperative TRUS provides an accurate diagnosis of RVT. In conjunction with TRUS-directed biopsies, directed management of these tumors could be achieved.

Adenoma, Villous↗

PubMed1997

Laparoscopic creation of stomas.

BACKGROUND: Some indications for laparoscopic bowel surgery are still controversial. However, the use of laparoscopic techniques for the treatment of benign disorders is less often challenged. Moreover, the morbidity of nonresectional procedures is less than that encountered with resectional cases. Therefore, stoma creation seems ideally suited to laparoscopy. The aim of our study was to assess the outcome of laparoscopic stoma creation. METHODS: All patients who underwent laparoscopic intestinal diversion were evaluated; parameters included age, gender, indication for the procedure, history of previous surgery, operative time, length of hospitalization, recovery of bowel function, and postoperative complications. RESULTS: Between March 1993 and January 1996, 32 patients of a mean age of 42.2 (range 19-72) years (14 males, 18 females) underwent elective laparoscopic fecal diversion (25 loop ileostomy, four loop colostomy, three end colostomy). Indications for fecal diversion were fecal incontinence (n = 11), Crohn's disease (n = 6), unresectable rectal cancer (n = 4), pouch vaginal fistula (n = 3), rectovaginal fistula (n = 2), colonic inertia (n = 2), radiation proctitis (n = 1), anal stenosis (n = 1), Kaposi's sarcoma of the rectum (n = 1), and tuberculous fistula (n = 1). Conversion was required in five patients (15.6%) due to the presence of adhesions (three), enterotomy (one), or colotomy (one). All of these five patients had undergone previous abdominal surgery and were operated on early in our experience. Major postoperative complications occurred in two patients (6%) and in both cases consisted of stoma outlet obstruction after construction of a loop ileostomy. One of the two patients had undergone prior surgery. This patient required reoperation, at which time a rotation of the terminal ileum at the stoma site was found. The other patient had a narrow fascial opening which was successfully managed with 2 weeks of self-intubation of the stoma. The mean operative time was 76 (range 30-210) min; mean length of hospitalization was 6.2 (range 2-13) days; stoma function started after a mean of 3.1 (range 1-6) days. Patients with previous abdominal surgery had a longer mean operative time (14/32; 117 min) compared to patients who had no previous surgery (18/32; 55 min) (p < 0.0002). These longer operative times and hospital stay were attributable to extensive enterolysis, which was required in some cases. CONCLUSION: In conclusion, laparoscopic creation of intestinal stomas is safe, feasible, and effective. Although the length of the procedure is longer in patients who have had prior surgery, previous surgery is not a contraindication, and even in these cases, a laparotomy can be avoided in the majority of patients. Lastly, care must be taken to ensure adequate fascial opening and correct limb orientation.

Adolescent↗

PubMed1995

Anoplasty for stenosis and other anorectal defects.

Anorectal strictures have been a serious problem for many years. The aim of this study was to determine the experience with anoplasty in our institution. A group of 17 patients, (six males and 11 females) were evaluated between May 1989 and February 1994, with an age range of 20 to 78 (mean 61 years). The main symptoms were difficulty to pass stool or constipation in 10 patients (58.8 per cent), rectal bleeding in eight patients (47 per cent), and anorectal pain in seven patients (41.1 per cent). The patients underwent clinical examination and the findings were anal stenosis in 13 patients (76.4 per cent), perianal fistula in two patients (11.8 per cent), key hole deformity in one patient (5.9 per cent), and unhealed chronic fissure in one patient (5.9 per cent). The technical procedure was S plasty in six patients (35.2 per cent) and advancement flaps in 11 (64.8 per cent). The follow-up period was between 3 and 59 (mean 18) months. In 16 patients, surgery had good results with improvement of their preoperative symptoms and preservation of continence. There was one septic complication; mean hospital stay was 3 days. In conclusion, anoplasty appears to be a safe and successful alternative for the treatment of anal stenosis.

Adult↗

PubMed1991

Study of the mandibular movements during swallowing.

The authors recorded the mandibular movement produced during the swallowing of 150 ml of water with the aid of a straw between the lips using a kinesiograph in a random sample of 66 people between the ages of 24 and 35. In each recording 13 variables were measured, and a descriptive analysis of each one was carried out. The authors' findings support that there is no dental contact during liquid swallowing with the aid of a straw between the lips.

Adult↗

PubMed1990

Study of mandibular movements during speech.

We recorded the mandibular movements produced during the reading of a text, in Spanish, using a kinesiograph in a random sample of 71 people aged 24 to 35. In each recording we measured nine variables and did a descriptive analysis of each variable. Our findings support that the mandibular movement during speech has some definite characteristics. The most important fact is that it could be a high percentage of occlusal contacts at incisal level during speech. This has to be taken into account when exploring an occlusal trauma of unknown etiology.

Adult↗

PubMed1988

[Computerized clinical protocol for occlusion].

In making a protocol it is necessary that all members of the team who are going to collect information have the same unity of criterion about the different variables that compose it. The drawing up of this document is as much or more necessary than the protocol itself. In this work we all data collected in the protocol and we give the explanations of each concept.

Diagnosis, Computer-Assisted↗