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Biomedical subjects

D T Hiyama

Publications and source records attributed to D T Hiyama.

18 recordsLinked to original sources

Laparoscopic aortobifemoral bypass.

PURPOSE: To determine the potential benefits of applying laparoscopic techniques for the intraabdominal insertion of aortofemoral grafts and to compare results with those of conventional surgery. METHODS: Having previously demonstrated the feasibility of a totally laparoscopic aortofemoral bypass technique using carbon dioxide peritoneal insufflation in a porcine model, we now report our first human experience with this laparoscopic technique in a 49-year-old man. RESULTS: The patient's postoperative course was marked by his minimal requirements for analgesia, early ambulation, and discharge from the hospital in the morning of the third postoperative day. CONCLUSIONS: The benefits of a laparoscopic approach to aortobifemoral bypass grafting in terms of financial savings and earlier rehabilitation in this patient was significant. This less-invasive procedure warrants further investigation.

Aorta, Abdominal↗

Laparoscopic aortobifemoral bypass: a case report.

In the past six years, laparoscopic surgery has gained widespread acceptance by both surgeon and patient. When compared to open surgical approaches, laparoscopic techniques for abdominal procedures lessen postoperative pain and morbidity, improve cosmesis, reduce hospital stay, facilitate early rehabilitation and return to normal activities. The application of laparoscopic techniques to intra-abdominal vascular procedures can be expected to provide similar benefits over conventional surgery.

Journal Article↗

Biliary disease during pregnancy.

BACKGROUND: Biliary disease during pregnancy is rare and the need for surgery in these cases is controversial. We evaluated our experience with biliary disease during pregnancy with regard to outcome and cost containment. PATIENTS AND METHODS: We reviewed the clinical course of pregnant women with biliary disease at the University of California at Los Angeles and Olive View-UCLA Medical Centers from 1988 to 1993. RESULTS: Seventy-two of 46,075 pregnant women presented with biliary disease (incidence 0.16%). Sixteen underwent surgery while pregnant, 5 in the first and 11 in the second trimester. No maternal or fetal deaths occurred secondary to medical or surgical management of biliary disease. Patients who were treated medically at initial presentation had a 69% rate of relapse prior to delivery, compared to no relapses in those treated surgically (P < 0.01). Patients who experienced relapse spent an average of 3.0 additional days in hospital. CONCLUSION: Surgical therapy for biliary disease performed in the second trimester of pregnancy does not increase morbidity and may help reduce relapses and additional days in hospital.

Acute Disease↗

Management of pancreatitis complicating pregnancy.

Pregnancy complicated by pancreatitis may lead to significant fetal and maternal morbidity and mortality. We reviewed the clinical course of 30 women who developed pancreatitis in our institution during pregnancy from 1988 to 1992. Pancreatitis complicated 0.07 per cent of pregnancies (n = 46,075) during this time period. The etiology was gallstones in 22 patients, alcohol in 2 patients, and idiopathic in 6 patients. Average age, multiparity, and symptoms at presentation were similar between patients with gallstone (GSP) or non-gallstone pancreatitis (NGSP). All patients were initially treated medically. GSP patients had significantly lower Ranson criteria than NGSP (0.7 vs. 1.9, P < 0.01), but response to initial therapy, need for emergency surgery, fetal outcome, and fetal and maternal mortality (0 per cent) were the same. Twenty-six of 30 patients were successfully treated with conservative management. A significantly higher relapse rate was seen in GSP than NGSP patients before delivery (72% vs. 0%, P < 0.05). These relapses required hospitalization 90 per cent of the time and resulted in 3.9 additional days per patient. Six patients underwent surgery during pregnancy (two in the first trimester and four in the second trimester) without fetal or maternal mortality and with normal birthweights and Apgar scores. No relapses or additional days in hospital were noted in GSP patients following surgery. We recommend that GSP patients presenting in the first or second trimester should, if possible, undergo cholecystectomy in the second trimester when the risk of anesthesia and premature labor are the lowest. Patients presenting in the third trimester should undergo surgery immediately post-partum.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Analysis of risk factors of postappendectomy intra-abdominal abscess.

BACKGROUND: Postappendectomy intra-abdominal abscesses (PAIAA) complicate the recovery of a small but significant fraction of patients with advanced appendicitis. STUDY DESIGN: A retrospective review of 1,184 patients with appendicitis was undertaken to define the clinical characteristics and risk factors associated with PAIAA. RESULTS: Thirty-three patients with 36 PAIAAs were found, an incidence of 2.8 percent. The mean age of patients with PAIAA was less than the overall group (16.9 versus 23.1 years, p = 0.002), and the mean core temperature of the PAIAA group was significantly higher (38.5 versus 38.2 degrees C). The incidence of PAIAA increased as the degree of appendiceal pathology worsened. The incidence of PAIAA was six (3.2 percent) of 190 in patients with gangrenous appendicitis and was 27 (8.7 percent) of 309 among patients with perforated appendicitis. Logistic regression analysis showed that independent predictors for the occurrence of PAIAA were young age and perforation. Although children presented with a higher rate of perforated appendicitis, this did not account for the younger age of the patients with PAIAA. Children (less than ten years of age) with perforation had PAIAA in ten (14 percent) of 69 cases compared with the incidence in the older patients with perforation of 17 (7.1 percent) of 240. CONCLUSIONS: These findings improve the surgeon's ability to identify patients at risk for PAIAA. Alterations in the perioperative management of perforated appendicitis, particularly in the pediatric patient, may reduce the occurrence of PAIAA.

Abdominal Abscess↗

Cecectomy for complicated appendicitis.

BACKGROUND: Cecal leak or disruption after appendectomy for complicated appendicitis is a consequence of severity of disease and is related to residual abscess cavity, inflammation, phlegmon, and nonviable intestine. In an attempt to improve results, we have begun to resect the cecum and other localized infected tissue in instances of complicated appendicitis in which the viability of the appendiceal base and adjacent cecum is questionable. STUDY DESIGN: This is a prospective series of all patients who have undergone resectional therapy for complicated appendicitis in the last four years. Patients with other inflammatory conditions of the right colon have been specifically excluded. RESULTS: Seventeen patients have undergone resectional therapy for complicated appendicitis. Thirteen (76.5 percent) were men; the mean age was 42.4 years. The mean temperature and leukocyte count were 37.8 degrees C and 16.1 x 10(9) per L, respectively. These patients presented with a mean of 6.8 days of abdominal pain. Nine had a palpable abdominal mass, and all had tenderness in the right lower quadrant. In ten patients an abscess was encountered at operation. While the extent of the resection varied, it generally included the cecum, part of the right colon, and 5 to 7 cm of terminal ileum. Fourteen patients had a primary anastomosis, while the other three had the creation of an ileostomy. Complications were encountered in only two patients: one wound infection and one pulmonary embolus. There were no instances of postoperative intra-abdominal abscess, intestinal obstruction, or fecal fistula. All patients had a benign postoperative course and were discharged on the average of 9.9 days postoperatively. The ileostomies in three patients have been closed and no complications have occurred on follow-up examination. CONCLUSIONS: We conclude that aggressive resectional therapy of the cecum during appendectomy in selected patients with complicated appendicitis is effective therapy and can be performed safely.

Abscess↗

The current role of small-bowel transplantation in intestinal failure.

Short bowel syndrome is the clinical manifestation of a fundamental reduction in the functional intestinal absorptive surface area and malabsorption. The development of total parenteral nutrition has improved the natural course of this disease. Home parenteral nutrition-related complications continue to generate significant morbidity and mortality for these patients. Small-bowel transplantation is an alternative to home parenteral nutrition. There are significant risks of graft rejection and the potential complications of long-term immunosuppression. Small-bowel transplantation is an option, but it should be reserved for patients no longer considered candidates for continued home parenteral nutrition.

Humans↗

Malignant melanoma: current management.

Malignant melanoma is increasing in frequency and is becoming one of the leading causes of cancer death. Early recognition and treatment is often curative. Recognition includes the identification of malignant precursors, the dysplastic nevus. Prognosis for survival and disease is dependent upon tumor thickness, level of invasion, anatomic location, growth pattern, ulceration as well as age and sex. Adequate biopsy of suspicious lesions is critical to both diagnosis and prognosis. Wide excision is the treatment of choice, with margins determined by tumor thickness. The management of regional lymph nodes remains controversial. Radical lymphadenectomy is indicated for clinically suspect adenopathy and may improve survival. There does not appear to be significant benefit of elective lymph node dissection for melanomas less than 0.76 mm or greater than 4 mm in thickness. Intermediate lesions may be managed in one of two ways: through careful follow-up with node dissection performed if clinical change is evident; or ELND may be performed. Ongoing trials to determine the benefit of ELND are presently under way. Isolated limb perfusion may be a desirable option for adjuvant therapy in the treatment of extremity melanomas, especially in patients with high-risk lesions or with disease recurrence since improved survival may be achieved. The role of surgical intervention in the management of distant metastases is limited but may have a role in palliation.

Combined Modality Therapy↗

Total and myofibrillar protein breakdown in different types of rat skeletal muscle: effects of sepsis and regulation by insulin.

Proteolysis is increased in sepsis, but it is not known whether myofibrillar and non-myofibrillar proteins are broken down in the same fashion, or respond to the same regulatory forces as in non-septic muscle. In this study, therefore, the effect of sepsis on total and myofibrillar protein breakdown in incubated rat extensor digitorum longus (EDL) and soleus (SOL) muscles was determined, and the response in vitro to different concentrations of insulin (10 to 10(5) microU/mL) of protein degradation was studied in incubated EDL muscles from control and septic rats. Sepsis was induced in rats weighing 40 to 60 g by cecal ligation and puncture (CLP). Control animals were sham operated. Sixteen hours after CLP or sham operation, intact EDL and SOL muscles were incubated for two hours in oxygenated Krebs-Henseleit bicarbonate buffer containing glucose (10 mmol/L) and cycloheximide (0.5 mmol/L), and total and myofibrillar protein breakdown was assessed from release into incubation medium of tyrosine and 3-methylhistidine (3-MH), respectively. Tyrosine and 3-MH were determined fluorometrically by high performance liquid chromatography (HPLC). Tissue levels of tyrosine and 3-MH remained stable both in control and septic muscles during incubation for two hours. The rate of tyrosine release was increased during sepsis by 58% (P less than .001) and 15% (NS) in EDL and SOL muscle, respectively. The corresponding figures for 3-MH were 103% (P less than .001) and 21% (NS). Tyrosine release was reduced by insulin at a concentration of 10(3) microU/mL in control muscle and at a concentration of 10(4) microU/mL in septic muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Factors affecting urea clearance during continuous hemodiafiltration in the canine model.

Continuous hemofiltration (CH) for the treatment of hypervolemia and electrolyte abnormalities in critically ill patients with acute renal failure has been shown to be an effective mode of therapy. This technique offers several advantages over peritoneal dialysis or hemodialysis: it is technically less complex, provides efficient ultrafiltration, and produces fewer hemodynamic disturbances. Recently, continuous hemodiafiltration (CHD) using a flow of dialysate fluid into the ultrafiltration chamber has been reported to augment urea clearance. The purpose of this study was to determine the blood flow and dialysate flow characteristics for optimal clearance of urea and creatinine using this technique. Six mongrel dogs (mean weight, 8.0 +/- 1.1 kg) underwent bilateral nephrectomy to induce anuric renal failure. Postoperatively, the animals were fluid resuscitated and fed ad libitum. Twenty-four hours following nephrectomy, venovenous hemofiltration was instituted. Blood flow was regulated via a roller pump, while dialysate flow was regulated using an infusion controller. An Amicon-30S hemofilter was used in the circuit. Blood flow rates of 5, 10, 15, 20, 25, and 30 mL/kg/min were used. Hemodiafiltration using Dianeal 1.5% solution was used in each animal. Net fluid losses via ultrafiltration were replaced using lactated Ringer's solution. Three of six animals survived for the complete five-hour hemofiltration period. No marked disturbances in electrolyte serum concentrations, including hyperkalemia, were observed. BUN concentrations were reduced by 35% and creatinine by 26%. Variation of the dialysate flow rate did not influence clearance of either urea or creatinine. Instead, clearance appeared to be flow dependent, and it was markedly increased at flow rates greater than 15 mL/kg/min.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗

Effect of sepsis on calcium uptake and content in skeletal muscle and regulation in vitro by calcium of total and myofibrillar protein breakdown in control and septic muscle: results from a preliminary study.

Because high calcium concentration in vitro stimulates muscle proteolysis, calcium has been implicated in the pathogenesis of increased muscle breakdown in different catabolic conditions. Protein breakdown in skeletal muscle is increased during sepsis, but the effect of sepsis on muscle calcium uptake and content is not known. In this study the influence of sepsis, induced in rats by cecal ligation and puncture, on muscle calcium uptake and content was studied. Sixteen hours after cecal ligation and puncture or sham operation, calcium content of the extensor digitorum longus (EDL) and soleus (SOL) muscles was determined with an atomic absorption spectrometer. Calcium uptake was measured in intact SOL muscles incubated in the presence of calcium 45 (45Ca) for between 1 and 120 minutes. Total and myofibrillar protein breakdown was determined in SOL muscles, incubated in the presence of different calcium concentrations (0; 2.5; 5.0 mmol/L), and measured as release into the incubation medium of tyrosine and 3-methylhistidine (3-MH), respectively. Calcium content was increased by 51% (p less than 0.001) during sepsis in SOL and by 10% (p less than 0.05) in EDL muscle. There was no difference in 45Ca uptake between control and septic muscles during the early phase (1 to 5 minutes) of incubation. During more extended incubation (30 to 120 minutes), muscles from septic rats took up significantly more 45Ca than control muscles (p less than 0.05). Tyrosine release by incubated SOL muscles from control and septic rats was increased when calcium was added to the incubation medium, and at a calcium concentration of 2.5 mmol/L, the increase in tyrosine release was greater in septic than in control muscle. Addition of calcium to the incubation medium did not affect 3-MH release in control or septic muscle. The results suggest that calcium uptake and content in skeletal muscle are increased during sepsis and that high calcium concentrations in vitro stimulate nonmyofibrillar protein breakdown. Muscles from septic animals may be more sensitive to the effect of calcium in vitro than muscles from nonseptic rats. Whether increased calcium uptake and content in skeletal muscle is partly responsible for accelerated muscle proteolysis during sepsis remains to be determined.

Animals↗

Hemodynamic and metabolic alterations during experimental sepsis in young and adult rats.

Cecal ligation and puncture (CLP) has been extensively used as a model of sepsis in adult rats. It is not known if the response to sepsis is similar in young and adult rats. This investigation was done to compare hemodynamic and metabolic alterations in young (four to six weeks of age, 60 to 90 grams) and adult (12 to 14 weeks of age, 270 to 340 grams) rats after CLP. In one series of experiments, survival rate was determined for 96 hours, and in other experiments, mean arterial blood pressure (MAP), heart rate (HR), white blood cell count, hematocrit, platelets, plasma glucose, lactate, amino acids, blood urea nitrogen (BUN), blood and peritoneal cultures and resting energy expenditure (REE) were determined eight and 16 hours after CLP. Levels of glycogen in liver and muscle were determined 16 hours after CLP. Mortality rate was similar in young and adult rats. MAP was stable throughout the course of sepsis, with no significant differences between the two groups of rats. HR was higher in young rats at all times studied. The adult rats became hyperglycemic after CLP while the young were hypoglycemic eight hours after CLP but normalized at 16 hours. Plasma lactate and BUN were similar in the two groups of rats, and no alterations were seen during sepsis. Both young and adult rats became hypoaminoacidemic after CLP. The phenylalanine to tyrosine ratio increased in a similar manner during sepsis in both experimental groups. REE was higher in young than in adult rats, but no significant changes were observed during the course of sepsis in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

Synthesis of acute-phase proteins in perfused liver following administration of recombinant interleukin 1 alpha to normal or adrenalectomized rats.

The purpose of this study was to investigate the effects of recombinant interleukin 1 alpha (rIL-1 alpha) on metabolic rate and synthesis of acute-phase proteins in intact and adrenalectomized rats. Animals were housed in metabolic cages with daily recording of food intake and body weight. Twice daily, for 3 days, the rats were injected intraperitoneally with 5000 LAF U of human rIL-1 alpha, purified from Escherichia coli. Control animals were pair-fed and received corresponding injections with saline. In the morning of the fourth day, resting energy expenditure (REE) was determined by indirect calorimetry, and synthesis of total secreted proteins, albumin, complement component C3, and seromucoid fraction was measured by radioimmunological method using rat-specific antisera and [3H]leucine in livers perfused for 2 hr. Food intake decreased by approximately 30% during rIL-1 alpha administration to intact rats. The decrease in food intake occurred later and was less pronounced in adrenalectomized rats receiving rIL-1 alpha. Growth rate was significantly reduced on the first day of rIL-1 alpha treatment in intact rats, while there was no effect on growth rate in adrenalectomized animals. After rIL-1 alpha administration, REE was increased by 26% in intact rats (P less than 0.001) and by 14% in adrenalectomized rats (N.S.). Increased synthesis rates of total secreted proteins, complement component C3, and seromucoid fraction were observed in livers of intact rats following rIL-1 alpha administration. In adrenalectomized rats, only production of C3 was significantly increased after treatment with rIL-1 alpha. Albumin synthesis rate was not changed in either group following rIL-1 alpha injections.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute-Phase Proteins↗

Synthesis of albumin and acute-phase proteins in perfused liver after burn injury in rats.

The acute-phase response that follows injury and sepsis is characterized by increased hepatic synthesis of specific secreted proteins while production of albumin is decreased. The effect of burn injury on specific synthesis rates of secreted hepatic proteins has not been reported. In this study, Sprague-Dawley rats received either a 30% flame burn (n = 12) or a sham burn (n = 12) and were allowed to recover for 11 days. Burned animals showed slower weight gains and a 25% to 30% higher resting energy expenditures compared with controls. On postburn day 11, synthesis of secreted hepatic proteins was measured by incorporation of leucine during a 2-hour isolated liver perfusion. Synthesis of total secreted proteins, the seromucoid fraction, and complement component C3 was significantly increased in burned animals, whereas synthesis of albumin was unaltered. In spite of unchanged albumin synthesis, plasma albumin concentrations were 50% lower in burned animals than in control animals throughout the postburn period. These findings suggest that decreased albumin synthesis is not the only mechanism responsible for persistent hypoalbuminemia that follows burn injury.

Acute-Phase Proteins↗