Pharmacokinetics of Oxaliplatin During Open Versus Laparoscopically Assisted Heated Intraoperative Intraperitoneal Chemotherapy (HIPEC): An Experimental Study

Background

Hyperthermic intraperitoneal chemotherapy (HIPEC) is being evaluated for patients with minimal residual or no residual disease after primary surgery and chemotherapy for stage III ovarian carcinoma. The technical feasibility of the laparoscopic approach for HIPEC has been demonstrated in a previous study. An experimental study on the porcine model was carried out to compare oxaliplatin pharmacokinetics during a laparoscopic-assisted procedure versus the coliseum technique for HIPEC.

Methods

Adult pigs received an HIPEC procedure that was based on 460 mg/m² of oxaliplatin over 30 minutes with a perfusate heated at 41°C to 43°C. The HIPEC drains were placed in the upper and lower quadrants of the abdomen. Peritoneal fluid and blood samples were collected every 10 minutes during the procedure, and the pharmacokinetics of oxaliplatin was studied.

Results

Two groups of 10 adult pigs were studied. All the procedures were successfully completed with an adequate intra-abdominal temperature and distribution. No major technical problems were encountered. At the end of the HIPEC, 41.5% of the molecule was absorbed in the laparoscopic group compared with 33.4% in the laparotomy group (P = .0543). Peritoneal oxaliplatin half-life (T_½) was significantly faster in the laparoscopic procedure (median, 37.5 vs. 59.3 minutes, P = .02). The area under the curve ratio of peritoneal to plasma reflects a more important oxaliplatin crossing through the peritoneal barrier in the laparoscopic procedure (ratio, 16.4 in the closed procedure vs. 28.1 in the open one; P = .03).

Conclusions

This study confirms the technical feasibility and reliability of the laparoscopic approach for HIPEC, and it extends knowledge concerning peritoneal drug absorption. Oxaliplatin absorption is far higher with laparoscopy in terms of time course in peritoneal perfusion. Clinical application in selected patients may be expected after further experimental investigation designed to define the adequate drug dosage.

     

Risk of pulmonary embolism after a negative spiral CT angiogram in patients with pulmonary disease: 1-year clinical follow-up study

PURPOSE: To evaluate the effect of pulmonary disease on diagnostic utility of spiral computed tomographic (CT) angiography in clinical practice. MATERIALS AND METHODS: Three hundred thirty-four patients, including 215 patients with pulmonary disease (group 1) and 119 patients with no history of respiratory disorder (group 2), were referred for thin-collimation CT angiography of the pulmonary circulation as the first-line diagnostic test. Patients with negative angiograms who had not received anticoagulation therapy and who could be clinically followed up at 3 months, 6 months, and 1 year were considered in the final study groups (n = 185); 135 patients had lung disease (group 3), and 50 patients had no history of a respiratory disorder (group 4). RESULTS: Between groups 3 and 4, no significant differences were found in the referral location, age, and risk factors. Confident evaluation of pulmonary arteries down to the subsegmental level was performed in 31 (23%) patients in group 3 and in 15 (30%) in group 4 (P =.5). Three episodes of acute pulmonary embolism (PE), all fatal, were diagnosed in group 3 patients; two cases occurred 14 days and one case occurred 6 months after the negative spiral CT scan. The negative predictive value of spiral CT angiography was 98% (175 of 178) in the study group in which follow-up was performed, with no significant difference between the values in groups 3 (98% [132 of 135]) and 4 (100% [50 of 50]). CONCLUSION: Underlying respiratory disease does not affect the negative predictive value of thin-collimation CT angiography, which appears to be a reliable tool in the work-up in this subgroup of patients with acute PE.     

Power Doppler imaging in detection of surgically induced indirect neoangiogenesis in adult moyamoya disease

OBJECT: Moyamoya is a rare, chronic disease that leads to the progressive narrowing and/or occlusion of the distal internal carotid and proximal cerebral arteries. Chronic cerebral ischemia ensues due to insufficient collateral blood supply. One potential treatment consists of the restoration of regional cerebral blood flow by direct or indirect revascularization surgery. The extent of neovascularization, especially in indirect procedures such as encephalomyosynangiosis (EMS), is currently evaluated with conventional angiography. Because this method is invasive and carries some risks, the authors investigated power Doppler imaging as an alternative noninvasive bedside procedure that can be used to assess surgically induced indirect revascularization in adult patients with moyamoya disease. METHODS: Twelve symptomatic patients with adult moyamoya disease (seven women and five men, mean age 38 +/- 17 years) underwent combined (direct and indirect) revascularization. They were then examined using conventional angiography and power Doppler imaging to assess the extent of revascularization within 120 days postsurgery. According to the number of intracranial vessels demonstrating opacification on conventional angiography and power Doppler imaging studies, EMS was graded as follows: 1, absent (0 vessels); 2, moderate (one-four vessels); and 3, extensive (> four vessels) for both methods. Examiners were blinded to the classification results for the procedure that they did not grade. All 24 hemispheres were examined. The visual grading of EMS revealed a highly significant agreement between conventional angiography and power Doppler imaging (Spearman rank coefficient, r = 0.92; p < 0.001) and there was 100% agreement of patency of the bypass between the direct and indirect methods. CONCLUSIONS: The authors found excellent agreement between the two methods. Therefore, power Doppler imaging is a valid noninvasive alternative to carotid artery angiography in evaluating direct and indirect revascularization.     

Mechanical Ventilation Affects Lung Function and Cytokine Production in an Experimental Model of Endotoxemia

Background: Mechanical ventilation using tidal volumes around 10 ml/kg and zero positive end-expiratory pressure is still commonly used in anesthesia. This strategy has been shown to aggravate lung injury and inflammation in preinjured lungs but not in healthy lungs. In this study, the authors investigated whether this strategy would result in lung injury during transient endotoxemia in the lungs of healthy animals.

Methods: Volume-controlled ventilation with a tidal volume of 10 ml/kg and zero positive end-expiratory pressure was applied in two groups of anesthetized-paralyzed rabbits receiving either intravenous injection of 5 [mu]g/kg Escherichia coli lipopolysaccharide (n = 10) or saline (n = 10) 2 h after the start of mechanical ventilation. The third group consisted of 10 spontaneously breathing anesthetized animals receiving lipopolysaccharide. Anesthesia was then continued for 4 h in the three groups while the ventilatory modes were maintained unchanged. Lung injury was studied using blood gases, respiratory physiologic variables, analysis of the bronchoalveolar lavage cell counts, and cytokine concentrations and lung pathologic examination.

Results: Significant histologic lung alterations, hypoxemia, and altered lung mechanics were observed in rabbits treated with mechanical ventilation and intravenous lipopolysaccharide but not in the mechanically ventilated animals injected with saline or in spontaneously breathing animals treated with lipopolysaccharide. Endotoxemic ventilated animals also had significantly more lung inflammation as assessed by the alveolar concentration of neutrophils, and the concentrations of the chemokines interleukin 8 and growth-related oncogen [alpha].     

Florid Cutaneous Papillomatosis, Malignant Acanthosis Nigricans, and Pulmonary Squamous Cell Carcinoma

A 72-year-old man had florid cutaneous papillomatosis (FCP), which is an obligatory paraneoplastic syndrome always associated with an internal malignancy. The cancer, which is usually intraabdominal and most often gastric in origin, evolves parallel to the FCP. This patient is the first case of FCP occurring in association with a lung malignancy. An association of FCP with other signs of internal cancer is common, with malignant acanthosis nigricans usually appearing many times with the sign of Leser-Trélat. FCP, malignant acanthosis nigricans, and the sign of Leser-Trélat are part of a continuum, developing by a common or similar pathogenic pathway due to an underlying malignancy producing a factor possibly similar to human epidermal growth factor.