Biomedical subjects

C C Compton

Publications and source records attributed to C C Compton.

At least 73 records · Page 4Linked to original sources

PubMed1995

Transforming growth factor alpha gene expression in cultured human keratinocytes is unaffected by cellular aging.

BACKGROUND: Cultured human keratinocyte grafts have been shown to stimulate endogenous reepithelialization of both chronic nonhealing and acute partial-thickness wounds. This effect is most likely mediated by cytokines that stimulate keratinocyte growth, such as transforming growth factor alpha. The effect of cellular age on cytokine expression by cultured grafts used for this purpose is presently undefined. In this study, transforming growth factor alpha gene expression in cultured foreskin keratinocytes from donors varying in age from 2 to 82 years was analyzed semiquantitatively by two separate methods, ie, Northern hybridization and competitive polymerase chain reaction. RESULTS: No pattern of decline in transforming growth factor alpha messenger RNA expression with increasing cellular age was observed by either analysis. CONCLUSION: The results indicate that expression of transforming growth factor alpha by cultured grafts may not be significantly affected by increasing cellular age and suggest that, even in the elderly, cultured autografts may be effective as pharmacologic agents for wound treatment.

Adult↗

PubMed1995

The generation of anchoring fibrils by epidermal keratinocytes: a quantitative long-term study.

Anchoring fibrils (AFs) are derived from basal keratinocytes, but the kinetics of their formation is unknown. In this study, de novo generation of AFs by cultured human keratinocyte autografts was assessed from 1 week to 6 years postgrafting. Within 2 weeks, AF population densities were equal to those of normal controls and remained normal thereafter. However, AF diameters were narrow compared to controls (P < 0.05) until 3 years postgrafting. The depth of extension of AF-anchoring plaque lattices into the subjacent stroma was normal by 3 weeks but, after 1 month, was typically 1.5-to 2-fold greater than normal. The findings indicate that: (1) basal keratinocytes immediately re-establish a full complement of AFs; (2) once reformed, AF populations remain normal in density over time; (3) nascent AFs are thin and require several years to reach full maturity; and (4) abnormally thick AF lattices may form over time in healed wounds.

Basement Membrane↗

PubMed1994

Selection factors for local excision or abdominoperineal resection of early stage rectal cancer.

BACKGROUND: This study reviews the experience of patients with early stage rectal cancer managed by local excision or abdominoperineal resection to clarify the relative indications and results of these two approaches. METHODS: From 1962 to 1991, 125 patients with T1 and T2 rectal cancer underwent local excision (56 patients) or abdominoperineal resection (69 patients). Outcome was analyzed by stage, treatment, and pathologic features of tumor grade and vessel involvement. RESULTS: The 5-year actuarial recurrence-free survival and local control was 87% and 96%, respectively, for 28 patients undergoing local excision with favorable histologic features (well or moderately well differentiated histologic findings without venous/lymph vessel involvement). These results were 57% and 68% for 28 patients with unfavorable histologic features (poorly differentiated histology and/or venous/lymph vessel involvement). For patients undergoing abdominoperineal resection, the 5-year actuarial recurrence-free survival and local control of 49 patients with favorable histologic features was 91% and 91%, respectively. These results were 79% and 89%, respectively, for patients with poorly differentiated histology or venous/lymph vessel involvement. CONCLUSIONS: For patients with T1 and T2 tumors having favorable histologic features, a satisfactory survival and local control was achieved for patients undergoing local excision or abdominoperineal resection. In contrast, patients with T1 and T2 tumors having poorly differentiated histologic features and/or venous/lymph vessel involvement undergoing local excision or abdominoperineal resection appeared to have decreased rates of survival and of local control. For these patients, radical resection combined with pelvic irradiation and 5-fluorouracil-based chemotherapy should be investigated.

Abdomen↗

PubMed1994

Cyst fluid cytologic analysis in the differential diagnosis of pancreatic cystic lesions.

Pancreatic cystic lesions include inflammatory pseudocysts, benign serous cystadenomas, and mucinous neoplasms, some of which are malignant. Cytologic analysis of cyst fluid has been proposed to diagnose pancreatic cysts before definitive therapy. The authors report an analysis of 31 pancreatic cyst aspirates: 9 pseudocysts, 5 serous cystadenomas, 8 mucinous cystic neoplasms, 4 mucinous cystadenocarcinomas, 2 papillary cystadenocarcinomas, 1 mucinous ductal adenocarcinoma with cystic degeneration, and 2 cystic islet cell tumors. All pseudocysts were correctly classified as probable inflammatory lesions, because of the presence of abundant acute inflammation and histiocytes and the absence of glandular epithelium. Three of five serous cystadenomas were correctly classified, based on the presence of small cuboidal cells in clusters with microvesicular cytoplasm containing glycogen. Eleven of 12 mucinous tumors contained round cells with large cytoplasmic mucin vacuoles or columnar cells containing cytoplasmic mucin. Malignancy was diagnosed in 5 of 7 carcinomas, 1 case was classified as suspicious for malignancy, and 1 case was nondiagnostic because of the absence of a cellular component. The authors concluded that pancreatic cyst fluid cytologic analysis is useful in differentiating mucinous from nonmucinous pancreatic cysts and may provide definitive evidence of malignancy. In some cases, serous cystadenoma can be diagnosed based on cytologic analysis. An inflammatory smear without epithelial cells suggests a pseudocyst, but these findings are nonspecific, as a similar pattern may occur when a cystic neoplasm undergoes degenerative changes. Therefore, pseudocyst remains a diagnosis of exclusion.

Biopsy, Needle↗

PubMed1994

Expression of CA 72-4 (TAG-72) in the fluid contents of pancreatic cysts. A new marker to distinguish malignant pancreatic cystic tumors from benign neoplasms and pseudocysts.

OBJECTIVE: The authors evaluated cyst fluid CA 72-4 as a tumor marker in the differential diagnosis of pancreatic cystic lesions. SUMMARY BACKGROUND DATA: Pancreatic cystic lesions include inflammatory pseudocysts, serious cystadenomas, and mucinous tumors. Mucinous tumors can be further subdivided into mucinous cystadenocarcinomas and premalignant mucinous cystic neoplasms. The clinical and radiologic features of these lesions are unreliable to make a preoperative diagnosis of these diagnostically difficult lesions. Analysis of aspirated cyst fluid was proposed as an aid to making the preoperative differential diagnosis. Currently, a number of parameters have been reported as useful markers in cyst fluid aspirates, including the tumor markers carcinoembryonic antigen and CA 15.3, enzymes (amylase, lipase, and amylase isoenzymes), relative viscosity, and cytologic analysis. However, owing to the rarity of pancreatic cystic tumors, experience with cyst fluid analysis is limited. To define additional markers that might be useful in the differential diagnosis of pancreatic cysts, the authors measured the tumor-associated glycoprotein 72 (TAG-72) in aspirates from 19 pancreatic cystic lesions. METHODS: Cyst fluid from 19 pancreatic cysts was obtained by needle aspiration. The tumor marker TAG-72 was measured by a commercial (CA 72-4) immunoassay. RESULTS: Cyst fluid CA 72-4 levels in mucinous cystadenocarcinomas were markedly elevated (mean, 10,027 U/mL; range, 780 to 34,853 U/mL) compared with that in pseudocysts (mean, 3.8 U/mL; range, < 3 to 5.7 U/mL) and serous cystadenomas (mean and range, < 3 U/mL; p < 0.001). The level of CA 72-4 in benign mucinous cystic neoplasms was intermediate (mean, 44.2 U/mL; range, < 3 to 137 U/mL), but it was statistically different from either carcinomas (p = 0.009) or benign cysts (p < 0.001).

Antigens, Tumor-Associated, Carbohydrate↗

PubMed1994

Endotoxin-induced ileal mucosal hyperpermeability in pigs: role of tissue acidosis.

Administration of lipopolysaccharide (LPS) to experimental animals leads to diminished mesenteric perfusion, increased ileal mucosal [H+] , and increased gut epithelial permeability to hydrophilic solutes. We sought to determine whether these phenomena are causally related. Experiments were performed in anesthetized pigs. Permeability was assessed by measuring the plasma-to-lumen clearance of fluorescein isothiocyanate dextran (4,000 Da; FD-4) by a segment of ileum perfused with Ringer lactate solution. Mucosal perfusion (Qmuc) and [H4+] were estimated using laser-Doppler flowmetry and tonometry, respectively. In an initial series of experiments, we showed that mucosal permeability was linearly correlated with mucosal [H+] in animals subjected to graded degrees of mechanically induced mesenteric ischemia (n = 14, R2 = 0.58, P < 0.002) or injected with graded doses of LPS (n = 11, R2 = 0.93, P < 0.0001). In a second series of experiments, we induced mucosal acidosis in normal pigs by mechanical ventilation with either a hypoxic (n = 7) or a hypercapnic (n = 5) gas mixture. In both groups, ileal mucosal permeability to FD-4 increased significantly (P < 0.05), although transmesenteric release of lactate increased significantly only in the hypoxic group. Qmuc was unchanged in both groups. These data suggest that mucosal acidosis, even in the absence of tissue ischemia or hypoxia, increases intestinal permeability to a macromolecular hydrophilic solute. Tissue acidosis may be an important factor contributing to LPS-induced gut mucosal hyperpermeability.

Acidosis↗

PubMed1994

Proliferating cell nuclear antigen and mitotic activity in rectal cancer: predictor of response to preoperative irradiation.

PURPOSE: This study examines the association between the pathologic response of rectal cancer after irradiation and its pretreatment proliferative state as assayed by proliferating cell nuclear antigen (PCNA) and mitotic activity. PATIENTS AND METHODS: Ninety patients with clinical stage T3 and T4 rectal cancer received preoperative irradiation followed by surgery. Pretreatment tumor biopsies were scored for PCNA activity (number of tumor cells staining immunohistochemically with an anti-PCNA monoclonal antibody) and the number of mitoses per 10 high-powered fields (hpf). Postirradiation surgical specimens were examined for extent of residual disease. RESULTS: The tumors of 33 of 90 patients (37%) exhibited marked pathologic downstaging (no residual tumor or cancer confined to the rectal wall) after preoperative irradiation. Two features were independently associated with the likelihood of marked pathologic regression after preoperative irradiation: lesion size and PCNA/mitotic activity. When stratified by tumor size, marked tumor regression occurred most frequently in smaller tumors with high PCNA/mitotic activity compared with larger tumors with lower PCNA/mitotic activity. Intermediate downstaging rates were seen for small or large tumors with moderate PCNA/mitotic activity. CONCLUSION: Tumor PCNA/mitotic activity predicts the likelihood of response to irradiation, which may aid in formulating treatment policies for patients with rectal cancer.

Adult↗

PubMed1994

Morphological and immunochemical differences between keloid and hypertrophic scar.

There are two types of excessive scarring, keloid and hypertrophic scar. Contrary to hypertrophic scars, keloids do not regress with time, are difficult to revise surgically, and do not provoke scar contractures. These two lesions require different therapeutic approaches but are often confused because of an apparent lack of morphological differences. We have investigated the collagen organization and the possible presence of alpha-smooth muscle (SM) actin-expressing myofibroblasts in these conditions. Keloids contain large, thick collagen fibers composed of numerous fibrils closely packed together. In contrast hypertrophic scars exhibit modular structures in which fibroblastic cells, small vessels, and fine, randomly organized collagen fibers are present. We confirm that such nodular structures are always present in hypertrophic scar and rarely in keloid. Furthermore, only nodules of hypertrophic scars contain alpha-SM actin-expressing myofibroblasts. Electron microscopic examination supports the above-mentioned differences in collagen organization and in fibroblastic features and shows the presence of an amorphous extracellular material surrounding fibroblastic cells in keloid. The presence in hypertrophic scar myofibroblasts of alpha-SM actin, the actin isoform typical of vascular SM cells, may represent an important element in the pathogenesis of contraction. Interestingly, when placed in culture fibroblasts from hypertrophic scars and keloid express similar amounts of alpha-SM actin, suggesting that local microenvironmental factors influence in vivo the expression of this protein. Thus several morphological and immunohistochemical differences exist between hypertrophic scar and keloid that are useful for the biological and pathological characterization of the two lesions.

Actins↗

PubMed1994

Expression of CA 15.3 protein in the cyst contents distinguishes benign from malignant pancreatic mucinous cystic neoplasms.

BACKGROUND: Inflammatory pseudocysts, serous cystadenomas, and mucinous cystic tumors comprise most cystic lesions of the pancreas. The mucinous tumors include mucinous cystic neoplasms, which are benign on histologic examination but have the potential for malignant transformation, and mucinous cystadenocarcinomas. Accurate preoperative classification of pancreatic cysts with clinical and radiologic criteria is often impossible, and as a result many cystic tumors are inappropriately treated as pseudocysts. Analysis of percutaneous needle-aspirated cyst fluid for tumor markers, enzymes, viscosity, and cytologic study has been proposed as a useful modality to distinguish mucinous from nonmucinous cystic lesions. However, no reliable cyst fluid parameter distinguishes benign from malignant mucinous tumors. METHODS: The concentration of the tumor marker CA 15-3 was measured by immunoassay in cyst fluid from six pseudocysts, five serous cystadenomas, three mucinous cystic neoplasms, and six mucinous cystadenocarcinomas. RESULTS: The concentration of CA 15-3 in the cyst fluid of mucinous cystadenocarcinomas was higher (mean, 178 units/ml; range, 40 to 392) than that of mucinous cystic neoplasms (mean, 4.7 units/ml; range, 0 to 14), serous cystadenomas (mean, 9.2 units/ml; range, 0 to 32), and pseudocysts (mean, 15.3 units/ml; range, 0 to 66). An upper cutoff value of 30 units/ml distinguished mucinous cystic neoplasms from mucinous cystadenocarcinomas with 100% sensitivity and 100% specificity (p = 0.01). CONCLUSIONS: Production of CA 15-3 appears to coincide with malignant transformation in pancreatic mucinous cystic neoplasms. We conclude that measurement of CA 15-3 levels in the cyst fluid is useful in the differentiation of benign from malignant pancreatic mucinous cysts.

Antigens, Tumor-Associated, Carbohydrate↗

PubMed1993

Gut macromolecular permeability in pancreatitis correlates with severity of disease in rats.

BACKGROUND: Increased intestinal macromolecular permeability could allow absorption of substances from the bowel into the systemic circulation and contribute to multiple organ system failure. METHODS: Mild, intermediate, and severe grades of pancreatitis were induced in rats using intravenous caerulein and intraductal glycodeoxycholic acid. [14C]polyethylene glycol (molecular weight, 3350 daltons; 1.1 microCi/142 mg) was instilled into the distal duodenum. At 24 hours, the animals were killed, ascitic fluid was collected for trypsinogen activation peptide measurement, and pancreatic specimens were collected and scored for based on the degree of necrosis, inflammation, and hemorrhage. RESULTS: Gut permeability to polyethylene glycol 3350 (PEG 3350) was increased in animals with early experimental pancreatitis (5.4% +/- 1.2%, n = 20) when compared with control animals (1.8% +/- 0.2%; n = 6) (P = 0.0005). Furthermore, intestinal macromolecular permeability to PEG 3350 correlated with severity of disease as predicted by the method of induction of pancreatitis (P = 0.0003), the histological findings (P = 0.0002), and total ascitic trypsinogen activation peptides content (P = 0.029). CONCLUSIONS: Increased gut permeability in experimental pancreatitis can be correlated with pancreatitis severity.

Animals↗

PubMed1993

Variability in cyst fluid carcinoembryonic antigen level, fluid viscosity, amylase content, and cytologic findings among multiple loculi of a pancreatic mucinous cystic neoplasm.

The procedure of percutaneous aspiration and analysis of cyst contents has been advocated to provide a preoperative diagnosis of pancreatic cystic lesions (pseudocysts and cystic tumors), but it is not known whether variation in the contents of separate loculi of a multilocular neoplasm might misrepresent the identity of the tumor. The authors measured the cyst fluid carcinoembryonic antigen (CEA) level, fluid viscosity, and amylase content and performed cytologic analysis on aspirates rates from ten different loculi of a single mucinous cystic neoplasm of the pancreas. The CEA levels were highly variable (median, 6,326 ng/mL; range, 962-64,670 ng/mL) but in all cases were diagnostic of a mucinous tumor. Fluid relative viscosity values were also variable (median, 2.4; range, 1.3-10+) but diagnostic in eight of nine aspirates. The amylase content in all of the loculi was low (< 91 U/L), and values were consistent with a cystic tumor. Cytologic analysis showed diagnostic mucin-secreting epithelial cells in nine of ten loculi. Although cytologic examination was nondiagnostic in one loculus, there were no false-positive results for malignancy. The combination of all four tests would not have resulted in misclassification of any of the tumors. The authors conclude that the characteristics of the contents of different loculi of pancreatic cystic neoplasms may be variable, but the use of a combination of tests still ensures accurate diagnosis.

Amylases↗

PubMed1993

Cyst fluid analysis in the differential diagnosis of pancreatic cysts. A comparison of pseudocysts, serous cystadenomas, mucinous cystic neoplasms, and mucinous cystadenocarcinoma.

Pancreatic cystic lesions include inflammatory pseudocysts, benign serous tumors, and mucinous neoplasms, some of which are malignant. Clinical and radiologic indices are often inadequate to discriminate reliably among these possibilities. In an attempt to develop new preoperative diagnostic criteria to assist in decisions regarding therapy, the authors have performed cyst fluid analysis for tumor markers (carcinoembryonic antigen: CEA, CA 125, and CA 19.9), amylase content, amylase isoenzymes, relative viscosity, and cytology on 26 pancreatic cysts. The cases included nine pseudocysts, five serous cystadenomas, 4 mucinous cystic neoplasms, 7 mucinous cystadenocarcinomas, and one mucinous ductal adenocarcinoma with cystic degeneration. Carcinoembryonic antigen levels were high (> 367) in all benign and malignant mucinous cysts, but were low (< 23) in the pseudocysts and benign serous cystadenomas, an indication that CEA discriminates between mucinous and nonmucinous cysts (p < 0.0001). Values for CA 125 were high in all malignant cysts, low in pseudocysts, and variable in mucinous cystic neoplasms and serous cystadenomas. Levels of Ca 19.9 were nondiscriminatory. Cyst fluid amylase and lipase content were variable but were generally high in pseudocysts and low in cystic tumors. Amylase isoenzyme analysis was useful to differentiate pseudocysts from cystic tumors. Measurement of the relative viscosity in cyst fluid showed high (> serum viscosity) values in 89% of mucinous tumors and low values (< serum) in all pseudocysts and serous cystadenomas (p < 0.01). Cytologic analysis of cyst fluids was of limited value in differentiating pseudocysts from serous cystadenoma, but in seven of eight mucinous tumors provided useful diagnostic information and correctly classified three of five malignant tumors. The authors conclude that cyst fluid analysis can provide a preoperative classification of these diagnostically difficult lesions. The combination of viscosity, CEA, CA 125, and cytology can reliably distinguish malignant cystic tumors and potentially premalignant mucinous cystic neoplasms from pseudocysts and serous cystadenomas. Amylase content with isoenzyme analysis is useful to identify pseudocysts.

Antigens, Tumor-Associated, Carbohydrate↗

PubMed1993

Resection margins in carcinoma of the head of the pancreas. Implications for radiation therapy.

A retrospective review of the pathology and clinical course of 72 patients undergoing resection of carcinoma of the head of the pancreas was undertaken to identify the frequency of tumor involvement at standard surgical transection margins (stomach, duodenum, pancreas, and bile duct) as well as the peripancreatic soft tissue margin and the potential clinical significance of these findings. Of 72 patients undergoing resection, 37 patients (51%) were found to have tumor extension to the surgical margins. The most commonly involved margin was peripancreatic soft tissue (27 patients) followed by pancreatic transection line (14 patients) and bile duct transection line (4 patients). For 37 patients with tumor present at a resection margin, there were no survivors beyond 41 months. No difference in survival or local control was seen between 14 patients receiving postoperative radiation therapy and 5-fluorouracil (5-FU) compared with 23 patients not receiving additional treatment. In contrast, the 5-year actuarial survival and local control of 35 patients undergoing resection without tumor invasion to a resection margin was 22% and 43%, respectively. The 5-year survival and local control of 16 patients receiving adjuvant radiation therapy and 5-FU was 29% and 42%, respectively, whereas these figures were 18% and 31% for 19 patients not receiving adjuvant therapy (p > 0.10). Because residual local tumor after resection is common, preoperative radiation therapy may be beneficial in this disease. It should minimize the risk of dissemination during operative manipulation and facilitate a curative resection by promoting tumor regression. Because local failure rates approach 60% after resection and adjuvant therapy even in cases having clear resection margins, intraoperative radiation therapy to the tumor bed at the time of resection also might be considered. Protocols evaluating the feasibility and efficacy of preoperative radiation therapy and resection with intraoperative radiation therapy for patients with pancreatic cancer are underway.

Actuarial Analysis↗

PubMed1993

Patterns of failure after pancreaticoduodenectomy for ampullary carcinoma.

The clinical courses of 41 patients with ampullary carcinoma were retrospectively reviewed to determine patterns of failure after resection. The five year actuarial local control and overall survival rates of 29 patients undergoing only pancreaticoduodenectomy were 69 and 55 percent, respectively. For 12 patients with "low risk" pathologic features (tumors limited to the ampulla or duodenum, well or moderately well-differentiated histologic factors, uninvolved lymph nodes or resection margins), the five year actuarial local control and survival rate was 100 and 80 percent, respectively. Adjuvant treatment may be unnecessary for this favorable subset of patients. On the other hand, the five year actuarial local control and survival after pancreaticoduodenectomy of 17 patients with "high risk" pathologic features (tumors invasive of the pancreas, poorly differentiated histologic findings, involved lymph nodes or resection margins) was only 50 and 38 percent, respectively (p < 0.05). In 12 patients at "high risk" who also received postoperative radiation therapy after pancreaticoduodenectomy, there was a trend toward better local control (83 percent), but there was no improvement in survival. Distant metastases (liver, peritoneum and pleura) were the dominant factor in determining outcome in this group. Therefore, we propose a trial of preoperative irradiation in hopes of enhancing these outcomes by reducing the risk of dissemination of cancer cells during surgical resection, especially among the 70 percent of patients with high risk pathologic features.

Adult↗

PubMed1993

Intraluminal oxygenation ameliorates ischemia/reperfusion-induced gut mucosal hyperpermeability in pigs.

We tested the hypothesis that intraluminal oxygenation can prevent increased gut mucosal permeability to a hydrophilic solute caused by mesenteric ischemia/reperfusion (I/R). Studies were performed using pentobarbital-anesthetized immature pigs. Paired 20 cm segments of ileum were perfused intraluminally at 200 ml/hr with either nitrogenated or oxygenated 37 degrees C Ringer's lactate. Beginning at T = -90 min, fluorescein disodium acetate was infused intravenously (12.5 mg/kg bolus, then 12.5 mg/kg/hr). Permeability was assessed by calculating the plasma-to-lumen clearance of fluorescein. Five pigs were subjected to complete mesenteric ischemia (T = 0-120 min) followed by reperfusion (T = 120-270 min). In nitrogenated segments, I/R resulted in a 1015 +/- 195% increase in fluorescein clearance (P < 0.01 vs baseline). In contrast, the increase in fluorescein clearance induced by I/R in oxygenated segments was only 264 +/- 63% (P < 0.01 vs baseline). Intraluminal oxygenation afforded significant (P < .01) protection against I/R-induced mucosal hyperpermeability at all time points from T = 150-270 min. Histologic sections revealed complete villous epithelial denudation in nitrogenated segments, whereas the mucosal epithelium was largely intact in oxygenated segments. After reperfusion, mucosal ATP levels normalized in oxygenated segments, but there was only partial recovery of ATP levels in nitrogenated segments. These data indicate that intraluminal oxygenation ameliorates mucosal hyperpermeability induced by I/R.

Adenosine Triphosphate↗

PubMed1993

Skin graft take and healing following 193-nm excimer, continuous-wave carbon dioxide (CO2), pulsed CO2, or pulsed holmium: YAG laser ablation of the graft bed.

BACKGROUND: Ablative lasers have been used for cutaneous surgery for greater than two decades since they can remove skin and skin lesions bloodlessly and efficiently. Because full-thickness skin wounds created after thermal laser ablation may require skin grafting in order to heal, we have examined the effect of the residual laser-induced thermal damage in the wound bed on subsequent skin graft take and healing. In a pig model, four different pulsed and continuous-wave lasers with varying wavelengths and radiant energy exposures were used to create uniform fascial graft bed thermal damage of approximately 25, 160, 470, and 1100 microns. Meshed split-thickness skin graft take and healing on the thermally damaged fascial graft beds were examined on a gross and microscopic level on days 3 and 7, and then weekly up to 42 days. RESULTS: Laser-induced thermal damage on the graft bed measuring greater than 160 +/- 60 microns in depth significantly decreased skin graft take. Other deleterious effects included delayed graft revascularization, increased inflammatory cell infiltrate at the graft-wound bed interface, and accelerated formation of hypertrophied fibrous tissue within the graft bed and underlying muscle. CONCLUSIONS: Ablative lasers developed for cutaneous surgery should create less than 160 +/- 60 microns of residual thermal damage to permit optimal skin graft take and healing. Pulsed carbon dioxide and 193-nm excimer lasers may be valuable instruments for the removal of full-thickness skin, skin lesions, and necrotic tissue, since they create wound beds with minimal thermal damage permitting graft take comparable to that achieved with standard surgical techniques.

Animals↗

PubMed1992

Are there patients with stage I rectal carcinoma at risk for failure after abdominoperineal resection?

The clinical courses of 64 patients undergoing abdominoperineal resection for Stage I lower rectal carcinoma (tumors confined to the muscularis propria without lymph node involvement) were reviewed to identify subsets at risk for failure. Twelve of 12 patients with tumors limited to the submucosa remained disease free without evidence of recurrence. Of the 52 patients with muscularis propria involvement, there have been eight failures with three patients having local failure only, three patients with local failure and distant metastases, and two patients with distant metastases only. The 6-year actuarial disease-free survival, local control, and freedom from distant metastases rates for patients with tumors invasive of the muscularis propria were 80%, 84%, and 88%, respectively. Patients with tumors exhibiting vascular/lymph vessel involvement were at even higher risk for failure. Although adjuvant treatment is infrequently advised for these patients, the use of radiation therapy and chemotherapy should be reconsidered for patients with Stage I lower rectal carcinoma, specifically for patients with tumors invasive of the muscularis propria with vascular/lymph vessel involvement.

Abdomen↗

PubMed1992

Middermal wound healing. A comparison between dermatomal excision and pulsed carbon dioxide laser ablation.

BACKGROUND: Continuous-wave carbon dioxide lasers are not widely used for the surgical removal of most skin lesions because it is difficult to control laser ablation and the extensive laser-induced thermal damage slows healing. Pulsed lasers provide means to reduce thermal damage produced during laser ablation and permit precise control of tissue removed during ablation. Using a swine model, we compared on a gross and microscopic level the healing of middermal wounds of similar depth and area created by a dermatome and a focused pulsed CO2 laser. RESULTS: Pulsed CO2 laser ablation removed skin precisely and bloodlessly with 85 +/- 15 microns (mean +/- SD) of residual thermal damage covering the surface of the wound. Compared with the dermatome, tissue reepithelialization was delayed in the laser wounds at day 3. By day 7, epithelial coverage of the laser-created wounds was not significantly different from the dermatome-created wounds. No significant difference in the appearance of the two wounds was noted at 42 days. CONCLUSIONS: We conclude that the focused pulsed CO2 laser is capable of precisely and bloodlessly ablating skin with conservation of residual subjacent adnexal elements, minimal early interference with epibolic epithelial outgrowth, and no pathologic effects on the wound healing process. Pulsed CO2 lasers may be a valuable instrument for the conservative ablation of skin and skin lesions.

Animals↗