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Biomedical subjects

M P Fried

Publications and source records attributed to M P Fried.

At least 19 recordsLinked to original sources
PubMed1992

Comparative study of laser and scalpel nerve transections.

This investigation was designed to compare standard scalpel transections of the tibial branch of the rat sciatic nerve with those performed using either a milliwatt carbon dioxide (CO2) or a potassium titanyl phosphate (KTP/532) laser. Four transection groups consisted of nerves sectioned with (1) scalpel (control), (2) milliwatt CO2 laser, (3) KTP/532 with microscope attachment, and (4) KTP/532 laser with 400-microns bare fiber. Each laser was used with the same parameters: 10 watts, 0.4-mm spot size, and continuous-wave mode. Horseradish peroxidase (HRP) was applied to the proximal stump for 30 min, and the animals were sacrificed 24 h later. Horseradish peroxidase (HRP)-labeled motoneuron cell bodies in the lumbar spinal cord were then counted. The average numbers of labeled neurons in each group were as follows: group I (n = 14) 518, group II (n = 8) 424, group III (n = 8) 351, and group IV (n = 8) 283. The standard deviations were quite large, however. When all laser transections were pooled and compared with paired scalpel transections, we found a significant difference, both by the paired t-test (P = 0.016) and by the Wilcoxon matched-paired test (P = 0.02). We conclude that laser transection significantly diminishes the number of neurons labeled by the retrograde transport of HRP.

Animals↗
PubMed1992

Laser surgery.

Explore the source record for details and available documents.

Humans↗
PubMed1992

Thermal effects on horseradish peroxidase uptake in laser nerve transections.

The authors previously reported that rat tibial nerves transected with CO2 or KTP/532 laser transmit less horseradish peroxidase (HRP) than those transected with a scalpel. This may be due to laser-specific effects or to thermal phenomena that are laser-independent. This study investigated potential thermal effects on the transmission of HRP through the tibial branch of the sciatic nerve in rats. Bilateral nerve transections were performed on 18 animals using a scalpel (control) or an electrocautery device, which simulated the thermal effects produced by lasers. HRP retrograde transport and deposition in the rat spinal cord were analyzed. Thirteen of 15 animals showed a higher number of HRP-labelled neurons on the scalpel side compared to the electrocautery side; a paired student's t test showed a significant difference (P = .028) in the numbers of HRP-stained cell bodies between the control group (x = 687.13 +/- 119.3) and the electrocautery group (x = 388.1 +/- 111.2). In conclusion, reduced HRP uptake in tibial nerves transected with lasers may be in part due to thermal effects produced by the lasers.

Animals↗
PubMed1991

The use of absorbable sutures in laser-assisted microvascular anastomoses.

The efficacy of the laser in performing microvascular anastomoses has been well established in the laboratory using a number of wavelengths. These studies have concluded that laser-assisted microvascular anastomoses are at least comparable to, if not superior to, ordinary suture techniques. The advantages have been the diminished foreign body reaction that occurs as a consequence of using only a few stay sutures to hold the vessels in approximation while the laser bonding is performed, as well as the rapidity of the surgery. We have already shown that absorbable sutures (polyglactin 910) are as efficacious as standard nonabsorbable sutures (nylon) in both arterial and venous microanastomoses. The current study was undertaken to see if the foreign body reaction could be diminished even further by the use of absorbable 10.0 sutures and compare these findings to laser-assisted microvascular anastomoses performed with nonabsorbable sutures. The carbon dioxide milliwatt laser was used to perform laser-assisted microvascular anastomoses in rat femoral arteries and veins. Patency rates and histological response were compared at intervals of 3 days and 1, 2, 4, 8, and 12 weeks postoperatively. Both arterial and venous patency rates were comparable (overall absorbable, 91.2%-52/57; overall nonabsorbable, 87.7%-50/57), as was the degree of inflammation and fibrosis. We conclude that absorbable sutures can be used for laser-assisted microvascular anastomoses and have the potential of allowing healing to occur without any foreign material within the surgical site.

Absorption↗
PubMed1991

Laser resistant stainless steel endotracheal tube: experimental and clinical evaluation.

A fire due to endotracheal tube (ET) ignition is a catastrophic event that may occur during laser surgery of the upper airway, regardless of the wavelength utilized. Although methods exist that permit laser surgery without an ET, this is frequently not feasible. The current investigation was undertaken to evaluate the efficacy of a double-cuffed stainless steel ET, first in the laboratory and subsequently in a clinical setting. Bench testing was performed using CO2 (both standard and milliwatt) and KTP/532 lasers. Only the distal polyvinyl chloride cuffed end of the tube was potentially ignitable, however, the appropriate use of saline to fill the cuffs allowed only for cuff perforation without ignition. Canine testing was performed in 10 animals: 4 dogs were intubated from 3 to 4.5 hours with the laser resistant stainless steel endotracheal tube (LRSS-ET) (Laser-Flex Tracheal Tube; Mallinckrodt Anesthesia Products, St. Louis, MO) and 2 with an aluminum tape wrapped red rubber ET. Visual and histological examination were performed in both groups at 3 and 7 days. Four dogs underwent CO2 laser laryngeal surgery with visual and histological examination performed at 7 days postoperatively. No untoward effects could be demonstrated due to the LRSS-ET. A clinical study was then performed in 24 patients who underwent laser surgery of the upper aerodigestive tract with either a CO2 or KTP/532 laser. In all cases ventilation was adequate, the shaft of the LRSS-ET proved impervious to the laser, and the distal end of the tube protected the tracheobronchial tree safely.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Laser-assisted microvascular anastomosis using CO2 and KTP/532 lasers.

The milliwatt carbon dioxide (CO2) laser has been shown to be an effective device for performing laser-assisted microvascular anastomosis (LAMA) with consistently high patency rates, minimal tissue disruption, and rapid surgical time as well as the potential for reduced inflammation due to fewer foreign bodies (sutures) in the wound. The purpose of this investigation was to determine the feasibility of using the potassium titanyl phosphate (KTP) laser to perform LAMA and to compare it to CO2 LAMA in both arteries and veins. Patency rates, inflammatory response, and course of healing were evaluated through histological analysis. Twenty-eight rats were divided into two groups, which underwent either CO2 or KTP LAMA and then were sacrificed at 3 days, and 1, 2, 4, 8, and 12 weeks postoperatively. Patency rates for arteries and veins were comparable for both wavelengths (CO2: 100% for arteries, 93% for veins; KTP: 93% for arteries, 93% for veins). Histological grading of inflammation and fibrosis showed no significant difference between the two groups. This study demonstrated the efficacy of using the KTP/532 laser in performing LAMA. We found the KTP and CO2 LAMA to have comparable patterns of tissue damage and course of healing. Although this experiment did not investigate the mechanism(s) of tissue welding, our results suggest that successful LAMA may be independent of wavelength.

Anastomosis, Surgical↗
PubMed1990

The efficacy of absorbable suture for microvascular anastomoses.

Although microvascular anastomoses are routinely performed with nonabsorbable sutures, a foreign body reaction can be stimulated that acts as a nidus for inflammation, infection, and possible thrombosis. Absorbable sutures should be able to diminish this reaction. There are sparse data describing the use of absorbable sutures for both arterial and venous anastomoses. This investigation compares standard microvascular anastomotic technique using nonabsorbable 10-0 sutures (nylon) with absorbable 10-0 sutures (polyglactin 910), using a previously reported tubed superficial epigastric flap model in rats. Patency rates and histologic responses are compared at intervals of 3 days and 1, 2, 8 and 12 weeks postoperatively. Arterial and venous patency rates were similar for both materials (overall nonabsorbable, 85.9%; overall absorbable, 84.4%). A somewhat increased inflammatory response was noted in the arterial absorbable group at 1 week and in both the venous and arterial nonabsorbable groups at 8 and 12 weeks postoperatively. The later finding most probably represents the continued presence of the nylon sutures. The incidence of intraluminal thrombosis was greater for nonabsorbable suture, occurring in two arterial and four venous anastomoses, compared with only one absorbable suture venous anastomosis. We conclude that nonabsorbable suture is as efficacious as standard absorbable material in both arterial and venous microanastomoses with the potential benefit of diminished foreign body reaction.

Absorption↗
PubMed1989

Comparative analysis of the safety of endotracheal tubes with the KTP laser.

The KTP laser has been used increasingly to treat various disorders of the upper aerodigestive tract. To establish the relative safety of the endotracheal tubes that are currently available, we performed laboratory testing of these tubes by exposing them to the KTP laser in an oxygen-rich environment. Based on our observations, tubes that were all metal or metal-wrapped endotracheal tubes were determined to be the safest. The advantage of using the all-metal tube was that it did not need wrapping. This tube also has a second distal cuff, which would allow for continued ventilation if the proximal cuff becomes disrupted. However, under these circumstances, insertion of a new nondisrupted tube is advised.

Alloys↗
PubMed1989

Carcinogenicity of dark liquor.

To investigate whether the non-alcohol content of distilled alcoholic beverages affects the carcinogenicity of the beverage, we conducted an epidemiologic study of laryngeal and hypopharyngeal cancer. We interviewed 384 cases (or spouses, for deceased cases), and compared their responses with those of 876 controls. We classed distilled liquors as dark or light, a rough division according to content of potentially carcinogenic compounds in the beverages. The relative effect on hypopharyngeal cancer risk was much stronger for those who reported high consumption of dark liquor (relative risk = 4.4, 90% confidence interval = 2.9, 6.8) than for those reporting comparable consumption of light liquor (relative risk = 1.3, 90% CI = 0.8, 2.1). For laryngeal cancer, consumption of dark liquor had a smaller effect, and there was little distinction between the effects of dark and light liquor. The data appear consistent with the theory that the non-alcoholic content of distilled alcoholic beverages is a determinant of cancer risk, and that alcoholic beverages act topically rather than systemically in their carcinogenic action.

Alcoholic Beverages↗
PubMed1988

The effects of anesthesia on middle-ear effusions.

Surgeons occasionally note a discrepancy between preoperative assessment of middle-ear effusion and operative observation during the placement of ventilating tubes in children's ears. This study was designed to determine whether this variance is secondary to the effects of inhalation anesthesia or misinterpretation of the preoperative exam. Observations were recorded by three distinctly different methods of measurement: the surgeon, the MD-2 Impedance Analyzer, and the Acoustic Otoscope immediately before and after induction of anesthesia. These results were then analyzed and compared with the operative findings. Anesthetic induction was shown to cause alteration in the presence of middle-ear fluid in less than 10% of cases.

Acoustic Impedance Tests↗
PubMed1988

Vagaries of thyroglossal duct cysts.

The thyroglossal duct cyst is the most common congenital cyst found in the neck, classically presenting as a paramidline mass in a healthy young adult. Fifty-three cases managed at the Brigham and Women's Hospital and Boston's Beth Israel Hospital over the past 10 years were reviewed. The unique presentation of papillary adenocarcinoma in TGDCs and findings in the elderly population are discussed. These cases represent both diagnostic and therapeutic challenges. The existing literature is correlated with our data, providing a treatise on management.

Adenocarcinoma, Papillary↗
PubMed1987

Microvascular anastomoses. An evaluation of laser-assisted technique.

The carbon dioxide milliwatt laser was used to perform microvascular anastomoses in 23 rat femoral arteries and 21 femoral veins. This technique was compared with conventionally sutured controls and then evaluated histologically at intervals of three to four days and 1, 2, 3, 4, 6, 8, and 12 weeks postoperatively. Patency rates in both methods, for arteries and veins, were comparable, confirming the feasibility of laser-assisted microvascular anastomoses. Moreover, the major benefit of the laser procedure was to allow for fewer sutures, thereby diminishing a foreign body reaction.

Animals↗
PubMed1987

T-cell subsets and natural killer cell function with squamous cell carcinoma of the head and neck.

Twenty-two patients with squamous cell carcinoma of the head and neck were studied to assess potential abnormalities in total T lymphocytes, T4/T8 ratios, and natural killer cell function. Total T-cell counts were reduced for the entire group with the greatest reduction occurring in individuals with hypopharyngeal tumors and/or stage IV disease. Helper to suppressor ratios were within the norm for the total group, but specific site variances were detected in patients with oral cavity and hypopharyngeal primary carcinomas. Similarly altered T4/T8 ratios were noted with stage III disease. Substantive differences in natural killer cell activity were not observed. These data suggest that perturbations in T-lymphocyte subsets can be associated with decreased survival.

Adult↗
PubMed1987

Head and neck applications of the milliwatt laser.

The head and neck surgeon often uses the carbon dioxide laser. With the advent of new instrumentation, the frequency of usage will increase. The CO2 miliwatt laser offers the advantages of tissue welding, as well as cutting and ablation by virtue of the small spot size produced combined with low power output. Potential applications include microvascular and microneural anastomoses. The milliwatt laser can be used endoscopically for tissue resection with a high degree of precision with power densities comparable to current CO2 lasers. Moreover, the milliwatt laser can be applied to otology for cutting and welding of the tympanic membrane, tissue removal, and stapedotomy.

Animals↗
PubMed1986

[Reconstruction of the cervical esophagus by the free transfer of a jejunal loop. An experimental study in dogs].

A study was performed in twenty dogs in order to evaluate the chronic effects of free jejunal transfer and possible subsequent radiation therapy. Ten dogs were sacrificed within one week after surgery, three survived twelve to twenty days, and seven survived longer than six weeks with only one completing a full course of radiation equivalent to 6,000 rads to the jejunal flap. Fistulization was the most frequent complication in short-term and intermediate survivors. Inanition due to a functional rather than anatomic stenosis and dysmotility was observed in the long-term survivors. Interval oesophagoscopy and biopsy was of no additional value in evaluating flap survival. The jejunum of the animal receiving radiation showed a greater submucosal inflammatory response when compared to the other animals. Attempts at intraoperative cooling of the jejunal segment did not increase bowel survival or diminish the rate of fistulization.

Animals↗