John Gogas

Central Venous and Mixed Venous Oxygen Saturation in Critically Ill Patients

Background: Although mixed venous O₂ saturation (SvO₂) accurately indicates the balance of O₂ supply/demand and provides an index of tissue oxygenation, the use of a pulmonary artery (PA) catheter is associated with significant costs, risks and complications. Central venous O₂ saturation (ScvO₂), obtained in a less risky and costly manner, can be an attractive alternative to SvO₂. Objectives: To investigate whether the values of ScvO₂ and SvO₂ are well correlated and interchangeable in the evaluation of critically ill ICU patients and to create an equation that could estimate SvO₂ from ScvO₂. Methods: Sixty-one mechanically ventilated patients were catheterized upon admission and ScvO₂ and SvO₂ values were simultaneously measured in the lower part of the superior vena cava and PA respectively. Results: SvO₂ was 68.6 ± 1.2% (mean ± SEM) and ScvO₂ was 69.4 ± 1.1%. The difference is statistically significant (p < 0.03). The correlation coefficient r is 0.945 for the total population, 0.937 and 0.950 in surgical and medical patients, respectively. In 90.2% of patients the difference was <5%. When regression analysis was performed, among 11 models tested, power model [SvO₂ = b0(ScvO₂)^b1] best described the relationship between the two parameters (R² = 0.917). Conclusions: ScvO₂ and SvO₂ are closely related and are interchangeable for the initial evaluation of critically ill patients even if cardiac indices are different. SvO₂ can be estimated with great accuracy by ScvO₂ in 92% of the patients using a power model.

Role of malignancy and preoperative embolization in the management of carotid body tumors.

The purpose of this retrospective study is to present our approach to the management of patients with carotid body tumors (CBTs), emphasizing the role of malignancy and preoperative embolization. Between 1975 and 1998 a series of 18 patients with CBTs were treated, and 16 of them underwent successful excision of the tumor. According to the Shamblin classification, six of the tumors were type I, six type II, and six type III. In three of these patients (two with type II tumors and one with type III) in whom preoperative embolization had been performed, mean intraoperative blood loss was 400 ml, whereas in the remaining 13 cases this loss was 700 ml. Two patients with intracranial tumor spread underwent only radiotherapy. Neither postoperative deaths nor strokes occurred. Temporary cranial nerve injury occurred in four cases (25%). Local lymph node invasion was found in two patients, establishing the diagnosis of malignancy. One of these patients developed distal metastases 3 years after the operation and was treated with radiotherapy and octreotide. Follow-up ranging from 30 months to 23 years (mean 5 years) revealed no local recurrence except for the two patients who were treated with radiotherapy only. In conclusion, surgical excision remains the treatment of choice for CBTs and can be performed without major risks and with low morbidity and mortality. Preoperative embolization is helpful by diminishing intraoperative bleeding, and malignancy, though rare justifies early management.

Management of Nonpalpable, Mammographically Detectable Breast Lesions

Abstract. A series of 151 women underwent 156 preoperative localizations of nonpalpable, mammographically detected breast lesions. Indications for biopsy were (1) a cluster of more than five fine microcalcifications; (2) a solid lump found by ultrasound investigation; and (3) a radiologic abnormality of the breast parenchyma. The lesions were localized preoperatively using the hook-wire method (Frank needle), and all biopsies were performed under general anesthesia. Carcinoma was discovered in 34 (21.8%) cases; in 22 (64.7%) it was a noninvasive cancer (9 with microinvasions) and in 12 (35.3%) an invasive carcinoma with a mean tumor diameter of 0.8 cm. The highest malignancy rate was found among those with microcalcifications (21 of 81 cancers, or 25.9%). Lymph node involvement was seen in 25% of patients with invasive carcinomas. In conclusion, the needle localization of nonpalpable breast lesions is a simple, accurate method for early detection of small cancers with favorable prognosis.

Metastatic melanoma in the gallbladder: Report of a case

Abstract.Both primary and secondary gallbladder melanomas are rare and, when a solitary melanoma is found in the gallbladder, it is difficult to determine if it is primary or metastatic disease. We report the case of a young woman found to have a single metastatic gallbladder melanoma. Surgical removal of a solitary metastatic focus remains the treatment of choice for isolated metastasis of a malignant melanoma; however, the effectiveness of complementary chemotherapy and immunotherapy is still being examined.

DNA ploidy and pS2 protein expression in breast cancer.

The DNA content of ductal breast carcinomas of varying histological grade was measured using static image cytometry and correlated with pS2 expression in the tumour cells. Our study was performed on imprint of surgical biopsies of 60 women with ductal breast cancer. A statistically significant difference was observed between pS2+ expression and grade of malignancy (P<0.001). The percentage of euploid tumours significantly decreased from grade I to grade II to grade III (P=0.01). The percentage of aneuploid tumours increased from pS2+ to pS2− breast tumours (P<0.001). These findings may be indicative of pS2 and DNA ploidy alterations and tumour aggressiveness.

Application of back propagation to the diagnosis of breast lesions by fine needle aspiration

Abstract We investigated the capability of the back propagation (BP) neural network (NN) in the distinction of benign from malignant breast lumps. The study was carried out on Giemsa stained smears from 68 carcinomas and 32 benign lesions. Using a custom image analysis system, 25 parameters describing the size, shape and texture of the cell nucleus were measured. Three thousand nuclei were used as a training set for the NN and the whole data set were used for the test. Additionally, 238 cells from cases without definite cytological diagnosis were evaluated by the system. The application of the BP neural network on the cellular level enabled correct classification of 87% of cells; at the patient level, correct diagnosis was achieved in 98% of cases, by using a hypothesis value of 50%. Our results indicate that the use of neural networks combined with image morphometry and statistical techniques could improve the diagnostic accuracy of fine needle aspiration of breast lesions and reduce the number of unnecessary biopsies.

Fournier's gangrene: still highly lethal.

ZusammenfassungWir behandelten 5 Patienten-4 Männer und 1 Frau (Alter 35–70 Jahre)—mit nekrotisierenden Infektionen des weichen Gewebes von Perineum und Skrotum. Infektionsherde waren bei 4 Patienten perirektale Abszesse und bei einem ein skrotaler Abszeß. In allen Fällen waren extensive Wundexzisionen und die i.v.-Gabe von Breitbandantibiotika erforderlich. Die Exzision erstreckte sich auf Skrotum, Perineal- und Inguinalzone, die Oberschenkel und die vordere Abdomenwand. Bei 2 Patienten mußte eine transversale Schlingenkolostomie bzw. Schlingensigmoidostomie durchgeführt werden. Nach unzureichender Drainage eines perirektalen Abszesses war eine Zweitoperation erforderlich. Zu spät wurden 3 Patienten an uns überwiesen; 1 Patient kam zu uns, nachdem er 2 Wochen lang Fieber hatte—er verstarb trotz forcierter Wundexzision an einer fulminanten Sepsis. Die Fournier-Gangrän—häufiger als gemeinhin angenommen—weist nach wie vor eine hohe Mortalität auf, die nur dadurch vermindert werden kann, daß das Krankheitsbild von seiten der Medizin erhöhte Aufmerksamkeit erfährt und die Behandlung sowohl der ursächlichen Erkrankung als auch der nekrotisierenden Fasziitis so früh wie möglich erfolgt.AbstractFive patients with necrotizing soft tissue infections of the perineum and scrotum are presented. There were one female and four male patients, aged from 35 to 70 years. Portals of entry were perirectal abscesses in four cases and a scrotal abscess in one case. All patients required extensive surgical debridement and intravenous broad-spectrum antibiotics. Operative debridement involved the scrotum, the perineal and inguinal area, the upper thighs and the anterior abdominal wall. One patient required transverse loop colostomy and one loop sigmoidostomy. One patient was reoperated on after inadequate drainage of a perirectal abscess. Three patients were referred to our unit after some delay, while one patient did not seek medical care until after being febrile for 2 weeks. Despite aggressive debridement, this last patient died of fulminant sepsis. Fourniers gangrene, which is not so rare as in generally considered, is still associated with a high mortality, which can be reduced only by improving medical awareness and early treatment both of the primary cause and of necrotizing fasciitis.

Cushing's syndrome: Analysis of 18 cases

Eighteen patients with Cushings syndrome were analyzed retrospectively. Eleven patients had diffuse or adenomatous hyperplasia, 5 an adenoma and 3 a carcinoma. Iodocholesterol scanning provides considerable help in localization of the disease. Surgical treatment, while curative for benign cases, affects only slightly the course of malignant disease.

Metastatic Retroperitoneal and Mediastinal Fibrosis as First Sign of Recurrence of Breast Cancer

We present three cases of metastatic fibrosis caused by breast carcinoma without any evidence of other metastatic disease. (excerpt)

Prediction of malignancy in solitary thyroid nodules in a country with endemic goiter.

From January 1962 through October 1975, 455 patients with single thyroid nodules were operated on at King Paul Hospital. Malignancy was proved in forty-three patients. The overall incidence of carcinoma was 9.5 per cent. A higher incidence of cancer was found in patients less than ten years of age (40 per cent), between eleven and twenty years of age (20 per cent), and more than sixty-one years of age (17.4 per cent). Malignant nodules were more frequent in males (17.5 per cent) than in females (8.3 per cent). Radioactive iodine scanning does not distinguish benign from malignant nodule. Solitary thyroid nodules require operative excision supplemented with replacement therapy.