Risk of Bowel Obstruction in Patients with Mesenteric or Peritoneal Disease Receiving Peptide Receptor Radionuclide Therapy.

Although radiation-induced mesenteritis or peritonitis can potentially exacerbate the risk of bowel obstruction, there are no data in the literature on the incidence of intestinal obstruction related to peptide receptor radionuclide therapy. Methods: The records of all patients treated with 177Lu-DOTATATE at Moffitt Cancer Center between April 2018 and October 2019 were evaluated. The number of patients who developed bowel obstruction within 3 mo of a 177Lu-DOTATATE treatment was divided by the total number of patients with preexisting peritoneal or mesenteric disease. Management strategies and outcomes were evaluated. Results: Of a total of 159 patients treated, 81 had baseline mesenteric or peritoneal disease, among whom 5 (6%) experienced at least 1 episode of bowel obstruction within 3 mo of treatment. Two of the patients underwent surgical exploration during obstruction describing a "frozen abdomen." All 5 responded at least temporarily to high-dose corticosteroid treatment and regained bowel function, but 2 patients eventually succumbed to progressive peritoneal disease. Conclusion: Peptide receptor radionuclide therapy can lead to bowel obstruction in patients with mesenteric or peritoneal disease, likely by inducing inflammation. Corticosteroids can potentially play a role in treatment and prophylaxis.

Low-Frequency (20 kHz) Ultrasonic Modulation of Drug Action.

We tested the effect of low-frequency ultrasound (LUS, 20 kHz, 4 W/cm2) on the function of rat mesentery and human pulmonary arteries with wire myography. The vessels were induced to contract with either noradrenaline or physiologic saline solution (PSS) with a high potassium concentration (KPSS) and then incubated with capsaicin (2.1 × 10-7 M, TRPV1 [transient receptor potential vanilloid 1] activator), dopamine (1 × 10-4 M, dopamine and α2-receptor activator), or fenoldopam (dopamineA1 receptor agonist, 1 × 10-4 M) with and without glibenclamide (1 µM, KATP [adenosine triphosphate {sensitive potassium channel (ATP)}-sensitive potassium channel] inhibitor and α2-receptor modulator), and insonated. Vessels were incubated in Ca2+-free PSS and induced to contract with added extracellular Ca2+ and noradrenaline. Pulmonary arteries were induced to contract with KPSS and dopamine. Then the vessels were insonated. LUS inhibited the influx of external Ca2+, inhibited the dopamine-induced vasoconstriction in the KPSS (glibenclamide reversible), reduced the capsaicin-induced vasorelaxation, increased the gentamicin-induced vasorelaxation and increased the dopamine-induced contraction in the KPSS in human pulmonary arteries.

A comparison of laparoscopic energy devices on charges in thermal power after application to porcine mesentery.

INTRODUCTION: Advances in energy devices have played a major role in the rapid expansion of laparoscopic surgery. However, complications due to these energy devices are occasionally reported, and if the characteristics of these devices are not well understood, serious complications may occur. This study evaluated various typical energy devices and measured temperature rises in the adjacent tissue and in the devices themselves. EQUIPMENT AND METHODS: We used the following 7 types of energy devices: AutoSonix (AU), SonoSurg (SS), Harmonic Scalpel (HS), LigaSure Atlas (LA), LigaSure Dolphin Tip (LD), monopolar diathermy (Mono), and bipolar scissors (Bi). Laparoscopy was performed under general anesthesia in pigs, and the mesentery was dissected using each energy device. Tissue temperature at a distance of 1 mm from the energy device blade before and after dissection was measured. Temperature of the device blade both before and after dissection, time required for dissection, and interval until the temperature fell to 100°C, 75°C, and 50°C were documented. RESULTS: Temperature of the surrounding tissue using each device rose the most with the Mono (50.5±8.0°C) and the least with the HS in full mode (6.2±0.7°C). Device temperature itself rose the highest with the AU in full mode (318.2±49.6°C), and the least with the Bi (61.9±4.8°C). All ultrasonic coagulation and cutting devices (AU, SS, and HS) had device temperatures increase up to ≥100°C, and even at 8 seconds after completing dissection, temperatures remained at ≥100°C. CONCLUSIONS: Because the adjacent tissue temperature peaked with the Mono, cautious use near the intestine and blood vessels is necessary. In addition, the active blades of all ultrasonic coagulation and cutting devices, regardless of model, developed high temperatures exceeding 100°C. Therefore, an adequate cooling period after using these devices is therefore necessary between applications.

[Mast cell reaction to total irradiation]. / Reaktsiia tuchnykh kletok na obshchee obluchenie.

A morphofunctional changes of peritoneal and mesenteric mast cell populations in rats from first minutes up to 10 day after irradiation in dose 5.5 Gr were studied. It is shown that the increased mast cell degranulation is of the first reactions of organism on irradiation. Mast cell reaction on irradiation is biphasic; the quick, short first phase is observed approximately during 0.5 h after irradiation, the gradual prolonged second phase reaches its peak about 5-12 h and continues at least during 10 days.

[The link between the parameters of the thrombus formation process and blood flow velocity in the microvessels of the rat mesentery]. / Sviaz' parametrov protsessa tromboobrazovaniia i skorosti krovotoka v mikrososudakh bryzheiki krysy.

The role of shear rate in the processes of thrombocytes adhesion and aggregation was studied in vivo and in vitro. Certain parameters were obtained describing the thrombo-formation process in the rat mesenteric venules in different blood flow velocities. The experimental model took into consideration the dependence of the thrombocytes activation period on the distance from lesioned portion of vessel's endothelium.

[Thrombogenicity of the arterioles and venules in experimental tumor growth]. / Trombogennost' arteriol i venul pri éksperimental'nom opukholevom roste.

The authors studied laser radiation induced thrombogenesis in microvessels--arterioles and venules--of the mesentery of tumor-carrier rats. Statistically significant increase of thrombogenic potential was revealed in the venules on the 7th day after reinoculation of Pliss' lymphosarcoma, and only a tendency to its increase in the arteries. At the same time an increase was noted of the aggregation activity of blood platelets and inhibition of their deaggregation. The results of the study open new aspects of the phenomenon of generalized changes in the system of regional blood circulation characteristic of tumor growth and indicate a new means of its study.

[Modeling of different degrees of microvessel laser-induced endothelium damage].

A comparative analysis of rat mesentery micro vascular reactions on thermal impact during radiation to the focused laser irradiation in UV and visible regions of spectrum is made. Local intravascular temperature rise during laser irradiation both impulse (lambda = 337 nm) and continuous (lambda = 532 nm) states causes thrombus formation. The thrombus development that determined by laser irradiation parameters gives a possibility to modulate different degrees of microvessel endothelium damage.

Survival after accidental extrahepatic distribution of Y90 microspheres to the mesentery during a radioembolization procedure.

We present the acute management and outcome of a patient after an accidental mesenteric distribution of Y90 microspheres during radioembolization (RE). This report describes and highlights: (1) the incidence of a significant reflux during a RE session while injecting into a replaced right hepatic artery from the superior mesenteric artery, (2) the appearance of diffuse mesenteric Y90 distribution in bremsstrahlung-imaging, (3) the management protocol with the radiation protection agent amifostine, (4) the development of typical adverse effects in the expected time window, and (5) survival of the patient without long-term sequelae. This report should sensitize physicians to this particular problem and may help to avoid as well as manage similar radioembolization incidences.

Radiation effects on mast cells: secretory ability, histamine release and recovery, and cell number.

We studied the effects of irradiation with a single fraction of high-energy electrons, in the absorbed dose range used in radiotherapy, on features related to the rat mesenteric mast-cell (MC) population. Such features were energy dispersive X-ray microanalysis for zinc, light and transmission electron microscopic changes, histamine content, and secretory ability of MCs when exposed to the potent secretagogue 48/80. The observation period was 14 days. Also studied were the effects of radiation on the number and histamine content of free peritoneal MCs. Irradiation-induced decrease in histamine content was delayed for at least two days and the rate of subsequent recovery of mesenteric histamine was approximately 70% below normal. This was corroborated by the findings of necrotic and fragmented mesenteric MCs during the entire experimental period. Fibroblasts and macrophages phagocytosed groups of MC granules as well as individual MC granules. A fraction of the extruded MC granules retained an almost normal appearance. This suggests that they were solubilized unduly slow presumably because the irradiation destroyed the mechanisms and enzymes which normally degrade the heparin-protein granule matrix and its heparin. Moreover, the irradiation suppressed the secretory ability of mesenteric MCs and significantly reduced the number of free peritoneal MCs. The findings indicate that the MC is a remarkably radiosensitive connective-tissue cell.

Proliferation studies of the endothelial and smooth muscle cells of the mouse mesentery after irradiation.

A continuous labelling technique was employed to study the effects of external beta-radiation on the proliferation of endothelial cells and smooth muscle cells in the mesenteric arterioles of mice. Labelled and non-labelled cells of either type were determined by autoradiographic techniques in control animals and at different times (3, 12 and 48 weeks) after single doses of 20 and 45 Gy (2000 and 4500 rads). The fraction of cells labelled, even after 7 days of repeated injections was very low in all instances. Calculations showed very long turnover times for the two cell populations in control animals (greater than 2 years for endothelium and greater than 3 years for smooth muscle). After 20 and 45 Gy, no significant increase in endothelial proliferation was seen except at 3 weeks. No significant increase in labelling was observed in smooth muscle at any time after irradiation. These labelling data have been compared with the pattern of cell depletion of the irradiated endothelium. It was concluded that the depletion was much earlier than expected for a slowly proliferating tissue, if all the cells were cycling very slowly. Such an early depletion is, however, consistent with cell death resulting from a small proportion of the cells having a short cell cycle. The recovery of the endothelial cell numbers between 9 and 12 months was not accompanied by a rise in the fraction of labelled cells. Its is suggested that repopulation may occur from outside the treated area.

[Clotting induction in the mesenterium and erosive stomach mucosa in wistar rats as the result of a catenoidal ultrasonic transducer]. / Tromboobrazuvane v mezenterium i erozirana stomashna ligavitsa na plukh poroda Wistar sled vusdeistvie s katenoidalen ultrazvukov preobrazuvatel.

The ultrasonic transducers and instruments used in surgery operate in the range of 1-10 MHz and release significant heat in the surroundings. They need additional cooling system which significantly raises the cost and impedes the equipment operation. Hemostasis can be successfully achieved by employing ultrasonic transducers that operate in the kilohertz range, avoiding the occurrence of inadmissible tissue overheat outside the area of the transducer performance. The paper presents results of the approbation of the effect of a periodical acoustic signal with frequency of 60 kHz over the erosive stomach mucosa and mesenterium of 28 rats, "Wistar" breed, and the period of tissue exposure is 1-10 min. A transducer-catenoidal semi-wave concentrator that provides maximum emitted power of the ultrasonic wave is used and thermal effects are avoided. It is proved that the use of a powerful and localized ultrasonic signal results in erythrocyte diapedesis and forms microhaemorrhagies together with an out-vessel coagulation in the rat stomach mucosa The tissue damages are strictly limited within the area of the emitter contact and they are subject to control during the ultrasonic performance.

[Blood pressure and mesenteric blood flow in rats during the infusion of biogenic amines. Effect of supralethal irradiation]. / Pression sanguine et flux mésentérique chez le rat pendant l'infusion d'amines biogènes. Influence d'une irradiation supraléthale.

The action of biogenic amines (noradrenaline, dopamine), infused at different concentration into the aorta of the urethane anesthetized control and irradiated rats for 2 min., was followed on the basis of systemic blood pressure and mesenteric blood flow. The mesenteric blood flow was measured by means of an electromagnetic flow meter. The changes observed i.e. after dopamine an increase in pressure and flow, after noradrenaline an increase in pressure and a decrease in flow with an increase after infusion had been stopped, correspond to those obtained in larger animals. In many, but not in all cases, the response is proportional to the log of the concentration of the amine infused. Irradiation with 2 kR, i.e. a dose which causes the animals to die from the gastrointestinal syndrome after 3 days, modified the response to dopamine and noradrenaline. The changes are, for noradrenaline, a greater pressure and a lower flow responses and for dopamine a greater pressure response at low and middle doses.