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Biomedical subjects

H W Merrick

Publications and source records attributed to H W Merrick.

At least 37 records · Page 2Linked to original sources
PubMed1991

Intraoperative radiation therapy for pancreatic, biliary and gastric carcinoma: the US experience.

The experience with pancreatic, biliary and gastric cancer in the US has demonstrated that IORT is technically a feasible and therapeutically relatively safe modality. However, much research remains to be done. The toxicity in humans of single large dose radiation to normal tissue has not been firmly established. Clinical studies must be able to demonstrate the efficacy of IORT as well as a therapeutic advantage for this approach. IORT is potentially a very effective adjuvant therapy in treating tumors which are technically difficult to treat surgically or which have a high rate of recurrence following radical surgery. The combination of surgery and IORT may improve local control of the tumor by removing gross disease and identifying areas of potential risk for recurrence. Regional and distant failure, however, remains a problem. Because of this, future investigations are underway to combine chemotherapy with IORT, surgery and EBRT. The effectiveness of IORT needs to be established with prospective randomized trials. The appeal of this procedure is demonstrated by its rapidly growing popularity, and this very appeal requires that the value of the procedure be determined.

Biliary Tract Neoplasms↗
PubMed1991

Percutaneous decompression for femoral neuropathy secondary to heparin-induced retroperitoneal hematoma: case report and review of the literature.

Retroperitoneal hematoma resulting in femoral nerve injury is a serious potential complication of systemic heparin anticoagulation. Review of the literature reveals lack of agreement with respect to conservative versus surgical management. The authors report the first case in which return of function was established by percutaneous decompression of a retroperitoneal hematoma in a patient who was not a candidate for immediate surgery. The favorable result suggests that percutaneous drainage may represent a reasonable alternative or first step in surgical treatment of this compression.

Adult↗
PubMed1990

Rat liver tolerance for partial resection and intraoperative radiation therapy: regeneration is radiation dose dependent.

We studied the feasibility of delivering a large single dose of intraoperative radiation as an adjuvant to partial hepatic resection. Intraoperative radiation therapy (IORT) was delivered to the remaining liver of 84 rats after partial hepatectomy to determine the acute and chronic effects of treatment on blood chemistry values, histology, survival, hepatic regeneration, and cellular appearance of the normal liver. Transient elevations in SGOT, SGPT, and alkaline phosphatase were attributed both to hepatectomy and to liver parenchymal damage induced by IORT. Microscopic examination upon necropsy, performed at frequent intervals post-treatment revealed hepatic capsular thickening with some alteration of liver architecture mainly underneath the capsule, with localized inflammation and some areas of necrosis. Survival in all groups was 100% at 45 days. Liver weight increase proved to be dose-dependent and displayed a bisphasic pattern. This study demonstrated that IORT is a feasible adjunct to surgical resection of the liver in the rat model.

Alanine Transaminase↗
PubMed1990

Radiation dose perturbation in the presence of permanent vascular-access injection ports.

Injection ports are commonly used to maintain permanent vascular access in patients with malignant disease. The injection ports allow blood sampling as well as infusion or injection of chemotherapeutic agents directly into the circulation. The access catheters are usually placed in the subclavian vein with the injection port being implanted in the intraclavicular area. These injection ports are entirely self-contained underneath the skin and may have been placed in an area which subsequently requires radiation treatment. A comprehensive study of the perturbation effects of the injection ports when placed in the path of the beam was carried out. All dose measurements were performed using stainless steel and titanium injection ports. The radiation beams were 6 MV and 10 MV X rays and 6, 9, 12, 15, and 18 MeV electrons. The data indicate that the presence of injection ports significantly alters the radiation dose and dose uniformity. For example, the dose underlying a stainless steel port is reduced by 47% when 18 MeV electrons are used. This paper presents the dosimetric data, discusses the clinical significance of the results, and provides recommendations for design modifications of the ports.

Catheters, Indwelling↗
PubMed1990

Magnetic resonance imaging of hepatic adenoma.

A case of hepatic adenoma imaged by magnetic resonance imaging (MRI) as well as with angiography, computed tomography, and radionuclide imaging is presented. Pathological correlation is also presented. Review of the literature of MRI of hepatic adenoma and related tumors is discussed.

Adenoma↗
PubMed1990

Fatty liver change as a result of hepatic artery infusion chemotherapy.

Direct hepatic arterial infusion of floxuridine (FUDR) (Roche Laboratories, Division of Hoffman-LaRoche Inc., Nutley, NJ, U.S.A.) has been used extensively in the treatment of metastases of colorectal tumors to the liver. The effectiveness of infusion and tolerance of the chemotherapy has been improved utilizing a totally implantable infusion pump delivery system. However, unequal distribution of drug infusion may occur to different parts of the liver parenchyma as demonstrated by hepatic arterial infusion scintigraphy (HAPS). We present a case of such unequal perfusion in which fatty metamorphosis of the liver occurred in the overperfused liver segment after FUDR therapy. The liver parenchymal changes were followed by serial computerized tomography scans and proven by biopsy during a minilaparotomy. Serial HAPS examinations show redirection of subsequent infusion to the opposite liver lobe due to parenchymal damage and vascular sclerosis. The importance of uniform liver perfusion and a rare dose-related effect of FUDR on liver parenchyma are thereby demonstrated.

Colonic Neoplasms↗
PubMed1990

Concomitant radiation therapy and constant infusion FUdR for unresectable hepatic metastases.

Ten patients with unresectable liver metastases from intraabdominal primary malignancies were treated with combined hepatic irradiation and hepatic artery infusion with FUdR using an Infusaid pump. The median survival for the entire group was 10 months. Four (40%) demonstrated an objective response to treatment: Three patients had a decrease in tumor mass on computed tomography (CT) scan, and one patient had a reduction in liver size as measured by palpation. The survival of two of the three patients whose tumor size was observed to be reduced on CT scan was significantly longer than that of the rest of the group (23, 37, and 12 months). Treatment was generally well tolerated with only mild side effects. Morbidity from chemotherapy did not appear to be enhanced by combination with hepatic irradiation. This form of treatment, although it has not demonstrated improved survival compared with other treatments in this setting, may be considered for adjuvant therapy in patients with hepatic metastases.

Abdominal Neoplasms↗
PubMed1990

A physiologic basis for the provision of fuel mixtures in normal and stressed patients.

It has been suggested that lipid is a preferred fuel in stressed patients. We evaluated glucose oxidation in 20 patients (sepsis, cancer of the colon, multiple trauma, controls) while they received TPN (5.65 mg glucose/kg/min). Respiratory quotient (RQ) was measured by indirect calorimetry and the percent VCO2 arising from the oxidation of glucose was measured using [U-14C] glucose. Since RQs were 1.0 or greater in all patients, the nonprotein energy utilized by them was calculated to be derived completely from glucose. However, the kinetic data showed that glucose contributed only 55-60% of the VCO2. Protein oxidation contributed less than 20% of the VCO2, as calculated from urinary nitrogen. The difference must have been derived from fatty acid oxidation. The glucose turnover that was not oxidized was presumed to be converted to lipid at an RQ of 8.6. The net oxygen consumption and carbon dioxide production from this overall distribution resulted in an RQ of about 1.0 with only 60% coming from glucose oxidation. Since all patients responded in the same manner, it appears that the proper ratio of glucose and lipid was dictated on a physiologic basis and not on the type of disease.

Adult↗
PubMed1990

CT of the abdomen after the Whipple procedure: value in depicting postoperative anatomy, surgical complications, and tumor recurrence.

We performed a retrospective study of CT scans in 29 patients who had undergone the Whipple procedure (radical pancreaticoduodenectomy) to study the CT appearance of the postsurgical anatomy and assess the use of CT in the evaluation of early postoperative complications and recurrent tumor. In the postoperative period, the scans from 15 patients revealed seven transient fluid collections; four deep abscesses, three of which were successfully drained under CT guidance; three superficial abscesses; and five cases of ascites. In 19 patients, CT scans were obtained up to 4 years after surgery to search for recurrent tumor. The most frequent site of recurrence was the liver. CT correctly identified liver metastases in six of seven patients and was falsely positive in one. Recurrence also was found twice in retroperitoneal lymph nodes; one time each in the mesenteric root, spleen, and lung base; and twice causing afferent loop blockage. Surgical proof of recurrence was obtained in eight cases. Our experience suggests that an understanding of the normal postoperative anatomy following the Whipple procedure is essential in evaluating postoperative CT scans. Scans obtained for detection of tumor recurrence should be optimized for imaging the liver because this was the most frequent site of recurrence.

Adult↗
PubMed1990

Aggressive therapy for cancer of the pancreas. Does it help?

Aggressive therapy clearly plays a role in the management of pancreatic cancer, be it localized to that organ, limited to the upper abdomen, or metastatic. A significant percentage of patients with resectable disease can be salvaged by radical resection of the cancer and aggressive adjuvant therapies. Five-year survival rates exceeding 30% have been reported from Japan. A supportive-care-only treatment philosophy ensures that almost all patients will die of cancer and that new treatment regimens will not be evaluated, creating a self-fulfilling prophecy. Such a policy is no longer tenable.

Adenocarcinoma↗
PubMed1989

Massive intraoperative atelectasis secondary to untreated mediastinal Hodgkin's disease: report of the hazard and review of the literature.

Mediastinal adenopathy in Hodgkin's disease has been known to cause relative airway compromise, particularly in the more vulnerable left mainstem bronchus. This has been infrequently reported to occur during general anesthesia and to cause respiratory embarrassment, representing a significant hazard. The possibility of its occurrence should be recognized. Preoperative evaluation of the airway by chest films and tomography, followed by radiation therapy in those patients at risk, is recommended to minimize the chances of respiratory complications during general anesthesia.

Adolescent↗
PubMed1989

Intraoperative endoscopic localization of jejunal angiodysplasia as a source of massive rectal bleeding.

Gastrointestinal bleeding from an unknown source presents a difficult diagnostic problem. Despite the number of diagnostic tests available, there are occasions when gastrointestinal bleeding requires operative intervention without preoperative localization of the bleeding site. This situation was encountered in the case described, in which a preoperative bleeding scan could only suggest that the small bowel in the left upper quadrant was the source of the bleeding. Intraoperative small-bowel endoscopy was important in confirming the diagnosis.

Endoscopy↗
PubMed1989

Treatment of cancer of the pancreas by precision high dose (PHD) external photon beam and intraoperative electron beam therapy (IOEBT).

Twenty-five patients with a diagnosis of unresectable adenocarcinoma of the pancreas were explored in the Clement O. Miniger (COMROC) IOEBT operating amphitheater at the Medical College of Ohio. Seventeen were treated with IOEBT (20-30 Gy, 15 or 18 meV electrons) PHD external beam radiation therapy (40-60 Gy, 1.8 Gy per fraction) plus appropriate operative biliary and gastrointestinal bypass procedures. No intraoperative complications were observed. Two patients died of causes that may have been treatment-related. Two patients developed abdominocutaneous fistulae. Pain was ameliorated in eleven of twelve patients. Jaundice was relieved in all patients. Four of ten patients with weight loss showed a reversal of that trend. Patient survival was not significantly different from that of patients treated with high-dose precision therapy alone.

Adenocarcinoma↗
PubMed1989

Role of scintigraphy in establishing optimal perfusion in hepatic arterial infusion pump chemotherapy.

Since 1982, physicians at the Medical College of Ohio, Toledo, have performed 41 hepatic intraarterial chemotherapy infusion pump implantations for palliative treatment of metastatic liver disease from various primary tumors of the gastrointestinal tract. Radionuclide hepatic arterial pump imaging has proven to be a very reliable, cost-effective, and uncomplicated method of evaluating liver perfusion as it relates to pump function, catheter integrity, and positioning. Confirmation of satisfactory hepatic perfusion is the key to acceptable treatment by this modality. In combination with periodic computed tomography (CT) scanning and CEA determinations, scintigraphy plays a major role in establishing effective therapy and aids in determining causal factors behind treatment failures.

Adult↗
PubMed1988

Biochemical and cellular effects of radiofrequency induced interstitial hyperthermia on normal canine liver.

Interstitial hyperthermia (44.0 +/- 0.5 degrees C for 40 minutes) was delivered to the livers of 16 dogs to determine acute effects of treatment on blood chemistry, histology, and cellular appearance of normal liver. SGOT in treated animals peaked immediately at 300 +/- 21 U/L (within 2 hrs) and returned to control value within 7 days. LDH levels peaked at 1 day post-treatment and again at 2 weeks (300 +/- 16 U/L and 340 +/- 25 U/L respectively) and returned to pre-treatment values by week 4. SGPT remained elevated for 6 to 7 days following hyperthermia, but returned to control value at 2 weeks. There was also a rise in alkaline phosphatase (200 +/- 14 U/L 1 day post-treatment), which returned to a pre-treatment level by week 3. Changes in serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, lactate dehydrogenase, and alkaline phosphatase were attributed to both liver parenchymal damage induced by hyperthermia and to surgery. Other deviations in the blood chemistries and hematological parameters measured were ascribed to the stress response from surgical intervention, or to the resultant hemodilution from fluids during surgery. Microscopic examination upon necropsy, performed 4 weeks post-operatively, displayed limited fibrosis with some alteration of liver architecture, generalized sinusoidal dilation and red blood cells in the space of Disse. Cellular ultrastructure changes showed an increase of myelin figures, but mitochondria and other cellular organelles remained essentially normal. Localized tissue inflammation and some loss of function occurred in response to localized hyperthermia for this volume of tissue at therapeutic temperatures. This study showed that the technique was feasible and confirmed that the parenchymal damage caused by interstitial hyperthermia did not produce the severe loss of function that might have been expected.

Alanine Transaminase↗
PubMed1987

Intraoperative interstitial hyperthermia in conjunction with intraoperative radiation therapy in a radiation-resistant carcinoma of the abdomen: report on the feasibility of a new technique.

The application of a new technique of intraoperative interstitial hyperthermia (IOHT) and intraoperative radiation therapy (IORT) was investigated for unresectable abdominal carcinoma. A 43-year-old white male presented with severe back pain due to metastatic adenocarcinoma in the left paravertebral area, producing erosion of the body of T12. The disease had not responded to external beam radiation therapy. The tumor was approached through a thoraco-abdominal incision and IOHT was delivered via interstitial electrodes. Temperature was monitored at 16 locations within the tumor. An LCF hyperthermia unit was utilized to deliver RF power and produced a treatment temperature of 43 degrees C for 60 minutes uniformly throughout the treatment volume. Immediately following hyperthermia treatment, the lesion was treated with 15 meV electrons via IORT to a tumor dose of 25Gy. The patient recovered without complication and had complete relief from pain. Posttreatment CT scans have demonstrated control of disease over a 5-month follow-up period. A clinical pilot study has been established to further investigate the application of this combination therapy.

Adenocarcinoma↗