Real-time in vivo assessment of radiofrequency ablation of human colorectal liver metastases using diffuse reflectance spectroscopy.

BACKGROUND: The success of radiofrequency (RF) ablation is limited by the inability to assess thermal tissue damage achieved during or immediately after the procedure. The goal of this proof-of-principle study was to investigate whether diffuse reflectance (DR) spectroscopy during and after RF ablation of liver tumours could aid in detecting complete tissue ablation. MATERIAL AND METHODS: DR spectra were acquired in vivo in eight patients undergoing RF ablation for unresectable colorectal liver metastases, using a disposable spectroscopy needle. Intraoperative ultrasound imaging was used for accurate positioning of the RF electrode and the spectroscopy needle. Spectral changes were quantified and correlated to tissue histopathology and follow-up CT imaging. RESULTS: For the lesions in which ablation was monitored by DR spectroscopy (N = 8), median tumour size was 1.6 cm (range 0.8-3.3 cm). We found an excellent correlation (97-99%) between thermal damage suggested by spectral changes and histology. DR spectroscopy allowed discrimination between non-ablated and ablated tissue, regardless whether the needle was placed in tumour tissue or in surrounding liver tissue. Additional measurements performed continuously during ablation confirmed that the magnitude of spectral change correlates with the histochemical degree of thermal damage. CONCLUSIONS: Diffuse reflectance spectroscopy allows accurate quantification of thermal tissue damage during and after RF ablation. Real-time feedback by DR spectroscopy could improve the accuracy and quality of the RF procedures by lowering incomplete ablation rates.

Optical sensing for tumor detection in the liver.

BACKGROUND: There is an increasing trend for optical guidance techniques in surgery. Optical imaging using Diffuse Reflectance Spectroscopy (DRS) can distinguish different tissue types through a specific "optical fingerprint". We investigated whether DRS could discriminate metastatic tumor tissue from normal liver tissue and thus if this technique would have potential for further implementation into surgical instruments or radiological intervention tools. METHODS: A miniaturized optical needle was developed able to collect DRS spectra between 500 and 1600 nm. Liver specimen of 24 patients operated for colorectal liver metastases were analyzed with DRS immediately after resection. Multiple measurements were performed and DRS results were compared to the histology analysis of the measurement locations. In addition, normal liver tissue was scored for the presence or absence of steatosis. RESULTS: A total of 780 out of the 828 optical measurements were correctly classified into either normal or tumor tissue. The resulting sensitivity and specificity were both 94%. The results of the analysis for each patient individually showed an accuracy of 100%. The Spearman's rank correlation of DRS-estimated percentages of hepatic steatosis in liver tissue compared to that of the pathologist was 0.86. CONCLUSIONS: DRS demonstrates a high accuracy in discriminating normal liver tissue from colorectal liver metastases. DRS can also predict the degree of hepatic steatosis with high accuracy. The technique, here demonstrated in a needle like probe, may as such be incorporated into surgical tools for optical guided surgery or percutaneous needles for radiological interventions.

Failure to extinguish fear and genetic variability in the human cannabinoid receptor 1.

Failure to extinguish fear can lead to persevering anxiety and has been postulated as an important mechanism in the pathogenesis of human anxiety disorders. In animals, it is well documented that the endogenous cannabinoid system has a pivotal role in the successful extinction of fear, most importantly through the cannabinoid receptor 1. However, no human studies have reported a translation of this preclinical evidence yet. Healthy medication-free human subjects (N=150) underwent a fear conditioning and extinction procedure in a virtual reality environment. Fear potentiation of the eyeblink startle reflex was measured to assess fear-conditioned responding, and subjective fear ratings were collected. Participants were genotyped for two polymorphisms located within the promoter region (rs2180619) and the coding region (rs1049353) of cannabinoid receptor 1. As predicted from the preclinical literature, acquisition and expression of conditioned fear did not differ between genotypes. Crucially, whereas both homozygote (G/G, N=23) and heterozygote (A/G, N=68) G-allele carriers of rs2180619 displayed robust extinction of fear, extinction of fear-potentiated startle was absent in A/A homozygotes (N=51). Additionally, this resistance to extinguish fear left A/A carriers of rs2180619 with significantly higher levels of fear-potentiated startle at the end of the extinction training. No effects of rs1049353 genotype were observed regarding fear acquisition and extinction. These results suggest for the first time involvement of the human endocannabinoid system in fear extinction. Implications are that genetic variability in this system may underlie individual differences in anxiety, rendering cannabinoid receptor 1 a potential target for novel pharmacological treatments of anxiety disorders.

Effect of preservation of the right gastro-epiploic artery on delayed gastric emptying after cytoreductive surgery and HIPEC: a randomized clinical trial.

BACKGROUND: Delayed gastric emptying (DGE) is a main complication with unknown origin after a cytoreductive surgery and hyperthermic intra-peritoneal chemotherapy (CRS-HIPEC). The aim of this study was to investigate if preservation of the right gastro-epiploic artery (GEA) during standard omentectomy would have a positive effect on gastric emptying after CRS-HIPEC. METHODS: Forty-two patients subjected to a CRS-HIPEC were randomized into two groups perioperatively before performing an omentectomy: in Group I (N = 21) omentectomy was performed with preservation of the GEA; in Group II (N = 21) omentectomy was performed with resection of the GEA. The primary endpoint was the number of days to full oral intake of solid food. Secondary endpoints were number of days to intended occlusion of gastrostomy catheter and total hospital admission time. RESULTS: No significant differences were discovered between both groups in any of the study endpoints after CRS-HIPEC. No significant differences were observed in patient or operation characteristics between the randomized groups. CONCLUSIONS: No association was demonstrated between preservation of the gastro-epiploic artery during omentectomy and gastric emptying after CRS-HIPEC. The extensive intestinal manipulation or the heated intra-peritoneal chemotherapy during surgery are more plausible causes of this phenomenon. This clinical trial was registered in the Netherlands at the Central Committee on Research involving Human Subjects (CCMO) under registration number P06.0301L.

Indication for oophorectomy during cytoreduction for intraperitoneal metastatic spread of colorectal or appendiceal origin.

BACKGROUND: The incidence of ovarian metastases at the time of peritoneal carcinomatosis, and the influence of such metastases on survival after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), are unknown. METHODS: This retrospective analysis included 194 women subjected to CRS and HIPEC since 2001. The incidence of ovarian metastases, disease-free survival and disease-specific survival were analysed. RESULTS: The histological diagnosis was colorectal cancer carcinomatosis in 108 patients, peritoneal mucinous carcinomatosis (PMCA) in 23 and disseminated peritoneal adenomucinosis (DPAM) in 63. Ninety-nine patients underwent oophorectomy during the HIPEC procedure. Ovarian metastases were confirmed in at least 52 per cent of the patients. There was a significant difference in disease-free survival between women with or without ovarian metastases in both PMCA and DPAM groups (P = 0·044 and P = 0·010 respectively). No significant differences in survival were found in the group with colorectal cancer carcinomatosis. CONCLUSION: When peritoneal carcinomatosis of colorectal or appendiceal origin is confirmed, at least 52 per cent of ovaries will have synchronous metastases. Disease-free survival after a HIPEC procedure for PMCA or DPAM is significantly lower in women with ovarian metastases. Oophorectomy during CRS for peritoneal carcinomatosis should be strongly considered.

Is stress a trigger factor for migraine?

BACKGROUND: Although mental stress is commonly considered to be an important trigger factor for migraine, experimental evidence for this belief is yet lacking. OBJECTIVE: To study the temporal relationship between changes in stress-related parameters (both subjective and objective) and the onset of a migraine attack. METHODS: This was a prospective, ambulatory study in 17 migraine patients. We assessed changes in perceived stress and objective biological measures for stress (saliva cortisol, heart rate average [HRA], and heart rate variability [low-frequency power and high-frequency power]) over 4 days prior to the onset of spontaneous migraine attacks. Analyses were repeated for subgroups of patients according to whether or not they felt their migraine to be triggered by stress. RESULTS: There were no significant temporal changes over time for the whole group in perceived stress (p=0.50), morning cortisol (p=0.73), evening cortisol (p=0.55), HRA (p=0.83), low-frequency power (p=0.99) and high-frequency power (p=0.97) prior to or during an attack. Post hoc analysis of the subgroup of nine stress-sensitive patients who felt that >2/3 of their migraine attacks were triggered by psychosocial stress, revealed an increase for perceived stress (p=0.04) but no changes in objective stress response measures. At baseline, this group also showed higher scores on the Penn State Worry Questionnaire (p=0.003) and the Cohen Perceived Stress Scale (p=0.001) compared to non-stress-sensitive patients. CONCLUSIONS: Although stress-sensitive patients, in contrast to non-stress-sensitive patients, may perceive more stress in the days before an impending migraine attack, we failed to detect any objective evidence for a biological stress response before or during migraine attacks.

Symptomatic abdominal aortic aneurysm with inferior vena cava malposition.

A 66-year old woman was admitted with an acute symptomatic abdominal aortic aneurysm. After preoperative assessment, she was directly operated on via transperitoneal approach. Intraoperatively, a left-sided inferior vena cava was diagnosed. The preoperative study of the abdominal computed tomography had not revealed this venous malformation. Retroperitoneal venous anomalies are a major source of unexpected haemorrhage during aortic reconstruction. Thus, for optimal preoperative preparation, a systematic close examination of the preoperative contrast enhanced CT scan of the abdomen is advised.

The prevalence of premonitory symptoms in migraine: a questionnaire study in 461 patients.

Migraine attacks are often preceded by premonitory symptoms. Prevalence rates of migraine patients reporting one or more premonitory symptoms show considerable variability and rates range between 12% and 79%. Sources of variability might be differences in study population or research design. Using a questionnaire, we retrospectively studied the prevalence of 12 predefined premonitory symptoms in a clinic-based population. Of 461 migraine patients, 374 (81%) responded. At least one premonitory symptom was reported by 86.9% and 71.1% reported two or more. The most frequently reported premonitory symptoms were fatigue (46.5%), phonophobia (36.4%) and yawning (35.8%). The mean number of premonitory symptoms per person was 3.2 (+/- 2.5). Women reported 3.3 premonitory symptoms compared with 2.5 symptoms in men (P = 0.01). Age, education, migraine subtype (with or without aura) and mean attack frequency had no effect on the mean number of symptoms per individual. In conclusion, premonitory symptoms are frequently reported by migraine patients. Sensitivity and specificity of premonitory symptoms for migraine need to be assessed using prospective methods.