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Biomedical subjects

A M Lacy

Publications and source records attributed to A M Lacy.

At least 37 records · Page 2Linked to original sources
PubMed1998

Effects of carbon dioxide vs helium pneumoperitoneum on hepatic blood flow.

BACKGROUND: Elevated intraabdominal pressure due to gas insufflation for laparoscopic surgery may result in regional blood flow changes. Impairments of hepatic, splanchnic, and renal blood flow during peritoneal insufflation have been reported. Therefore we set out to investigate the effects of peritoneal insufflation with helium (He) and carbon dioxide (CO2) on hepatic blood flow in a porcine model. METHODS: Twelve pigs were anesthetized and mechanically ventilated with a fixed tidal volume after the stabilization period. Peritoneal cavity was insufflated with CO2 (n = 6) or He (n = 6) to a maximum intraabdominal pressure of 15 mmHg. Hemodynamic parameters, gas exchange, and oxygen content were studied at baseline, 90 mm and 150 min after pneumoperitoneum, and 30 min after desufflation. Determination of hepatic blood flow with indocyanine green was made at all measured points by a one-compartment method using hepatic vein catheterization. RESULTS: A similar decrease in cardiac output was observed during insufflation with both gases. Hepatic vein oxygen content decreased with respect to the baseline during He pneumoperitoneum (p < 0.05), but it did not change during CO2 insufflation. Hepatic blood flow was significantly reduced in both the He and CO2 pneumoperitoneums at 90 min following insufflation (63% and 24% decrease with respect to the baseline; p < 0.001 and p < 0.05, respectively) being this decrease marker in the He group (p = 0.02). CONCLUSIONS: These findings suggest that helium intraperitoneal insufflation results in a greater impairment on hepatic blood flow than CO2 insufflation.

Animals↗
PubMed1998

Application of composite resin for single-appointment anterior and posterior diastema closure.

Due to aesthetic and periodontal factors, patients often seek treatment to close diastemata. This condition may be eliminated by either direct or indirect techniques. Indirect techniques generally require multiple visits to facilitate the placement of laminate, crown, or bridge restorations, and involve significant financial expense. Direct techniques can be economical and successful, although they present unique challenges in the achievement of satisfactory proximal contacts and contours. This article describes three clinical techniques that may be employed to treat anterior and posterior diastemata in a single appointment.

Adult↗
PubMed1997

Liver transplantation for alcoholic cirrhosis with anti-HCV antibodies.

The results of orthotopic liver transplantation (OLT) in patients with alcoholic liver cirrhosis (ALC) are currently similar to those obtained in patients with other indications. However, the frequent association of ALC with hepatitis C virus (HCV) infection may impair these results. We retrospectively studied the consequences of HCV infection on survival and graft function in 59 patients with ALC undergoing OLT. Patients were classified into two groups depending on their HCV serology before transplantation: group 1 comprised 24 anti-HCV-positive patients, and group 2, 35 anti-HCV-negative patients. Patient and graft survival were similar in both groups. Liver function tests 1 and 4 years after OLT showed AST and ALT values that were significantly higher in group 1 patients and post-transplant histologically proven chronic hepatitis was found in 45% and 61% of these patients at 1 and 4 years, respectively. We conclude that pretransplant HCV infection in patients with ALC does not affect survival after OLT. However, one must bear in mind the high incidence of post-transplant chronic hepatitis secondary to recurrence of HCV infection and be cautious when drawing this conclusion.

Adult↗
PubMed1997

Postoperative complications of laparoscopic-assisted colectomy.

BACKGROUND: This study was performed to prospectively assess the complications of 118 consecutive patients who underwent laparoscopic assisted colorectal resections. METHODS: The variables included were: indication for surgery, type of resection, duration of operation, duration of postoperative ileus, length of hospital stay, port-site recurrence, and complications in relation to the laparoscopic technique. RESULTS: 118 Laparoscopic-assisted procedures were performed between July 1992 and October 1995. Surgical indications were: 106 patients for colonic malignancy, six for diverticulitis, two for Crohn's disease, two for benign polyps, one for endometriosis, and one for ischemic colitis. Fifteen patients required conversion to open techniques for completion of the operations (12.7%). The mean operating time was 168.8 min. The amount of operative blood loss was 98 ml. The mean time for passing flatus was 36 +/- 16 h. Mean postoperative stay was 5.4 (range 3-13) days. Eight patients (6.8%) sustained complications: four unrelated to laparoscopy (three wound infection, one anastomotic leak); and four complications related to the laparoscopic approach: one small-bowel obstruction, one trocar injury, one rotation of the anastomosis, and one misdiagnosed synchronous adenocarcinoma. CONCLUSIONS: We suggest that with the development of improved technical devices and more experience, the indications for laparoscopic colectomy should continue to expand. The low incidence of infectious complications suggests an important role for the laparoscopic approach to colorectal surgery.

Adult↗
PubMed1996

Effect of venovenous bypass on perioperative renal function in liver transplantation: results of a randomized, controlled trial.

Although venovenous bypass (VVBP) has been suggested to protect the kidneys during liver transplantation and its systematic use has therefore been recommended, this beneficial effect of VVBP has not been clearly demonstrated. In a prospective, randomized, controlled trial, 77 patients receiving liver transplants for chronic liver disease were allocated to be supported with VVBP (group 1, 38 patients) or not (group 2, 39 patients). Both groups were similar in relation to preoperative clinical and laboratory data and operative transfusion requirements. Inulin clearance and urinary beta(2)-microglobulin and N-acetyl-beta-D-glucosaminidase (NAG) excretion (to determine glomerular filtration rate and tubular damage, respectively) were measured at different perioperative periods (anesthesia induction, hepatectomy, anhepatic phase, biliary anastomosis, and 24 hours after surgery). A significant decrease in inulin clearance and increase in tubular damage markers were observed in the anhepatic phase, which only partly improved in the subsequent phases. No significant differences were observed between groups 1 and 2 at any perioperative phase, except during the anhepatic phase, in which a more marked renal function impairment occurred in group 2 patients. However, renal function on the 7th postoperative day and the need for hemodialysis/ hemofiltration during the 1st week were similar in both groups. Among 40 variables analyzed, only low mean arterial pressure at anesthesia induction was identified as an independent predictor for early postoperative severe renal failure (inulin clearance < 10 mL/min/1.73 m(2) at the 24th postoperative hour), with no significant relationship between this complication and the use of venovenous bypass. Renal function markedly deteriorates during liver transplantation, and renal impairment persists during the early postoperative period. Because VVBP support is not associated with any clear benefit in renal function, its systematic use does not seem to be justified.

Acute Kidney Injury↗
PubMed1996

Hepatocellular carcinoma and cirrhosis. Results of surgical treatment in a European series.

OBJECTIVE: The authors analyze the outcomes of patients with hepatocellular carcinoma (HCC) and cirrhosis who underwent liver resections. BACKGROUND: Liver resection is the best option for HCC arising from hepatic cirrhosis. The experience of Western centers with these patients is shorter than the Asian series. METHODS: Forty-eight consecutive patients with cirrhosis and HCC who underwent liver resections were studied after a similar diagnostic and therapeutic process. Survival and cumulative recurrence were calculated according to pathologic findings. RESULTS: Factors influencing survival at 3 years were as follows: type of resection, absence of vascular invasion, size of the tumor, absence of satellite nodules, and the number of nodules. Factors influencing the rate of recurrence at 3 years were the presence of vascular invasion and the presence of satellite nodules. Patients with favorable prognostic factors have a good survival rate with an acceptable recurrence rate. CONCLUSIONS: Identification of prognostic factors may help in the selection of the appropriate treatment for these patients with HCC and cirrhosis.

Adult↗
PubMed1996

[Paraesophageal hernias in elderly patients. An indication for laparoscopic surgery].

Paraesophageal hernias are uncommon conditions which appear mainly in elderly people, frequently associated with sliding hernias or gastric volvulus. Considered a high risk pathology, surgical management is preferred to avoid serious complications. Due to advanced age and operative risks, a laparoscopic approach was performed in the three patients with paraesophageal hernia. In mixed hernias, a Nissen or Toupet fundoplication and closure of the hiatal defect was carried out. In a case with gastric rotation, reduction of the herniated stomach and posterior partial fundoplication with gastropexy was performed. No postoperative complications occurred and recovery was satisfactory. Laparoscopic management seems to be a good choice for elective treatment of paraesophageal hernias in elderly patients.

Aged↗
PubMed1996

An effective technique for extended proximal contacts in composite resin restorations.

Obtaining a firm anatomic contact has been a difficult criteria in placing Class II posterior composite restorations. Various techniques have been developed and a number of products marketed to accomplish this task, but none have combined the necessary qualifications of ease, simplicity, and effectiveness for consistent and predictable results. To address this challenge, two innovative devices--a precontoured (biplanar concave) sectional matrix band and a light--focusing tip-have been developed. Using a clinical case presentation, this article describes the application of these devices to obtain high quality proximal contacts, even in widely separated teeth. The learning objective of this article is to familiarize clinicians with this procedure. The technique is simple and universally applicable with a variety of posterior composite materials and placement methods.

Bicuspid↗
PubMed1996

[Relation of the levels of systemic prostaglandins and hemodynamic changes present during orthotopic transplant of the liver].

The aim of this study is to investigate the role of prostaglandins (PGI2 and TXA2) in relation with the hemodynamic alterations occuring after graft reperfusion in patients undergoing OLT. A total of 40 patients with liver cirrhosis were studied. Systemic 6-keto-PGF1 alpha and TXB2, stable metabolites of PGI2 and TXA2 respectively, were determined at the radial artery, at four different surgical stages: basal, hepatectomy, anhepatic, and 10 minutes after graft reperfusion. Overall results showed that 6-keto-PGF1 alpha levels were significantly elevated during hepatectomy (1143 +/- 204) when compared to values in the basal stage (p = 0.007). During hepatectomy, 6-keto-PGF1 alpha levels did not correlate to systemic vascular resistance index (SVRI), neither with the cardiac index (IC) nor with the medial arterial pressure (MAP) in the same stage. During the anhepatic stage, only IRVS was inversely correlated with 6-keto-PGF1 alpha levels (p = 0.004): there was no relation with MAP and CI. During reperfusion no correlations were observed between 6-keto-PGF1 alpha levels and MAP, CI or SVRI. We conclude that systemic PGI2 levels are very high in cirrhotic patients undergoing OLT. The absence of correlation between the magnitude of changes in hemodynamic parameters and 6-keto-PGF1 alpha levels during reperfusion of the new liver suggests that other factors must play a role in these hemodynamic changes.

Analysis of Variance↗
PubMed1995

Prostacyclin, thromboxane, and oxygen free radicals and postoperative liver function in human liver transplantation.

The aim of this prospective study is to evaluate prostanoid (prostacyclin and thromboxane) and lipid peroxide levels at the portal and hepatic veins, and their relation to immediate postoperative liver function. Nineteen patients with liver cirrhosis undergoing orthotopic liver transplantation were prospectively studied. Blood samples were obtained within 5 min and 1 and 2 hr after reperfusion of the new liver, through a catheter placed at the portal vein in the recipient and another at the left hepatic vein in the donor liver. Plasma prostacyclin and thromboxane were analyzed by HPLC and RIA. The formation of lipid peroxides was determined and expressed in terms of thiobarbituric acid-reacting substances. Immediate postoperative liver function was evaluated using the transaminase levels within the first 48 hr and the early postoperative graft function score, as described previously. After reperfusion, only determinations at 5 min were related with liver function. Either prostacyclin (R = -0.61, P = 0.004) levels at the hepatic vein or prostacyclin production (subtraction between hepatic and portal vein levels) (R = -0.47, P = 0.04) correlated significantly with the early postoperative graft function score. Besides, there was a significant relationship between lipid peroxide production as measured by thiobarbituric acid-reacting substances and a worse early postoperative graft function score (R = 0.61, P = .005). These results suggest that prostacyclin released after liver grafting attenuates preservation and reperfusion damage of the liver, supporting the hypothesis that there is an imbalance of prostanoids within the microvasculature in patients with a compromised postoperative liver function. Our results agree with the involvement of some degree of lipid peroxidation products in the damage of hepatocytes during anoxia and reperfusion.

6-Ketoprostaglandin F1 alpha↗
PubMed1995

Laparoscopic cholecystectomy in cirrhotic patients. Indication or contradiction?

Liver cirrhosis is considered a contraindication to laparoscopic cholecystectomy for the moment. Here we are reporting on results in the surgical treatment of gallstone disease in cirrhotic patients by laparoscopic means. We reviewed the experience over the final period of time in 11 patients since the introduction of laparoscopic procedures in our unit. The index of conversion rate was 9.1% (1/11). The morbidity was nil. The average length of hospital stay was 1.8 days (1-6 days). We propose the use of laparoscopic cholecystectomy in gallstone disease in patients with liver cirrhosis as first-line surgical treatment.

Adult↗
PubMed1995

Laparoscopic-assisted resection of a gastric lipoma.

Laparoscopic excision of a gastric lipoma is reported here. The diagnosis was done preoperatively be computed tomography, which gave evidence of fat tissue due to its low attenuation. The patient undergoes a complete submucosal excision enjoying the benefit of the laparoscopic approach with rapid postoperative recovery. This procedure offers a good alternative to open laparotomy in the treatment of benign gastric tumours.

Female↗
PubMed1995

Short-term outcome analysis of a randomized study comparing laparoscopic vs open colectomy for colon cancer.

The authors examined the impact of the laparoscopic approach on the early outcome of resected colon carcinomas. The role of laparoscopic techniques in the treatment of colon carcinomas is questionable. Previous studies have suggested technical feasibility of surgical resections of these cancers by laparoscopic means and have implied a benefit to laparoscopic technique for patients undergoing colorectal resections. A prospective, randomized study was conducted comparing laparoscopic assisted colectomy (LAC) open colectomy (OC) for colon cancer. We present the preliminary results in relation to the short-term outcome and judge the feasibility of the laparoscopic procedure to as a way of performing accurate oncologic resection and staging. Benefit has been demonstrated with LAC in this setting. Passing flatus, oral intake, and discharge from hospital occurred earlier in LAC- than OC-treated patients. The mean operative time was significantly longer in the LAC group than in the OC group. The overall morbidity was significantly lower in the LAC group. No significant differences were observed between both groups in the number of lymph nodes removed or the pathological stage following the Astler-Coller modification of the Dukes classification. The laparoscopic approach improves the short-term outcome of segmental colectomies for colon cancer. However, the further follow-up of these patients will allow us to answer in the near future whether or not the LAC may influence the long-term outcome.

Adenocarcinoma↗