Non-conventional vascular accesses for the management of superior vena cava syndrome in patients with Intestinal Failure. Case series and systematic review.

BACKGROUND: Type III Intestinal Failure (IF) is a devastating clinical condition.characterized by the inability of the gut to absorb necessary macronutrients, and/or water and electrolytes, requiring Parenteral Nutrition (PN) as chronic therapy. Long-term PN may lead to life-threatening complications; the loss of central venous access (LCVA) is the most frequent and challenging. To date, few studies in the literature have reported the relevance of Non-conventional Vascular Accesses (NCVA) in the management IF as part of the comprehensive multidisciplinary care. METHODS: A retrospective analysis of a database collected from January 2006 to December 2019 was performed using SPSS v25.0 for statistical analysis, followed by a systematic review, using the PRISMA.methodology RESULTS: From January 2006 to December 2019, 184 NCVA were placed in 71 patients with LCVA as IF-related complication; 173 were placed in 61 patients by interventional radiology (IR) and 11 NCVA were placed in 10 patients by the surgical team during the intestinal transplant (ITx) operation. From the 173 IR procedures 166 (95.9%) were successful with 3 ± 2.7 procedures/patient; average catheter permanence rate was 738.68 ± 997 days; complications related to the procedures occurred in 18/173 (10.4%), including two deaths. On the other hand, among the 11 NCVA implanted by the surgical team, 7 (64%) were successful and were safely withdrawn 30 days after ITx when were no longer needed; 2 (18%) catheters malfunctioned during the first week and could not be further used, and 1 was accidently removed; average catheter permanence rate was 26 ± 4 days. There was one complication (9%) requiring laparotomy; there was no mortality associated the procedure in this group. A systematic review was conducted to evaluate the success and safety of NCVA as part of the treatment of HPN-related complications; from 337,542 papers, 14 studies were included. A total of 28 HPN-patients with LCVA received NCVA; 34 procedures were successfully performed, while procedure-related complications were reported in 11.7%, as well as one death. CONCLUSIONS: The data analyzed show that NCVAs may be successfully placed by expert teams, allowing to sustain long-term PN, as well as increasing the Intestinal Transplantation applicability for candidates in the extreme need of vascular access.

Brain oxygen and metabolism during circulatory arrest with intermittent brief periods of low-flow cardiopulmonary bypass in newborn piglets.

OBJECTIVE: We performed this study to determine whether brief intermittent periods of low-flow cardiopulmonary bypass during deep hypothermic circulatory arrest would improve cortical metabolic status and prolong the "safe" time of deep hypothermic circulatory arrest. METHODS: After a 2-hour baseline, newborn piglets were placed on cardiopulmonary bypass and cooled to 18 degrees C. The animals were then subjected to 80 minutes of deep hypothermic circulatory arrest interrupted by 5-minute periods of low-flow cardiopulmonary bypass at either 20 mL x kg(-1) x min(-1) (LF-20) or 80 mL x kg(-1) x min(-1) (LF-80) during 20, 40, 60, and 80 minutes of deep hypothermic circulatory arrest. All animals were rewarmed, separated from cardiopulmonary bypass, and maintained for 2 hours (recovery). The oxygen pressure in the cerebral cortex was measured by the quenching of phosphorescence. The extracellular dopamine level in the striatum was determined by microdialysis. Results are means +/- SD. RESULTS: Prebypass oxygen pressure in the cerebral cortex was 65 +/- 7 mm Hg. During the first 20 minutes of deep hypothermic circulatory arrest, cortical oxygen pressure decreased to 1.3 +/- 0.4 mm Hg. Four successive intermittent periods of LF-20 increased cortical oxygen pressure to 6.9 +/- 1.2 mm Hg, 6.6 +/- 1.9 mm Hg, 5.3 +/- 1.6 mm Hg, and 3.1 +/- 1.2 mm Hg. During the intermittent periods of LF-80, cortical oxygen pressure increased to 21.1 +/- 5.3 mm Hg, 20.6 +/- 3.7 mm Hg, 19.5 +/- 3.95 mm Hg, and 20.8 +/- 5.5 mm Hg. A significant increase in extracellular dopamine occurred after 45 minutes of deep hypothermic circulatory arrest alone, whereas in the groups of LF-20 and LF-80, the increase in dopamine did not occur until 52.5 and 60 minutes of deep hypothermic circulatory arrest, respectively. CONCLUSIONS: The protective effect of intermittent periods of low-flow cardiopulmonary bypass during deep hypothermic circulatory arrest is dependent on the flow rate. We observed that a flow rate of 80 mL x kg(-1) x min(-1) improved brain oxygenation and prevented an increase in extracellular dopamine release.

Brain oxygenation and metabolism during selective cerebral perfusion in neonates.

OBJECTIVE: To investigate the possible neuroprotective effects of selective cerebral perfusion (SCP) during deep hypothermic circulatory arrest on brain oxygenation and metabolism in newborn piglets. METHODS: Newborn piglets 2-4 days of age, anesthetized and mechanically ventilated, were used for the study. The animals were placed on cardiopulmonary bypass, cooled to 18 degrees C and put on SCP (20 ml/(kg min)) for 90 min. After rewarming, the animals were monitored through 2h of recovery. Oxygen pressure in the microvasculature of the cortex was measured by oxygen-dependent quenching of phosphorescence. The extracellular level of dopamine in striatum was measured by microdialysis and hydroxyl radicals by ortho-tyrosine levels. Levels of phosphorylated cAMP response element binding protein (pCREB) in striatal tissue were measured by Western blots using antibodies specific for phosphorylated CREB. The results are presented as mean+/-SD (p<0.05 was significant). RESULTS: Pre-bypass cortical oxygen pressure was 48.9+/-11.3 mmHg and during the first 5 min of SCP, the peak of the histogram, corrected to 18 degrees C, decreased to 11.2+/-3.8 mmHg (p<0.001) and stayed near that value to the end of bypass. The mean value for the peak of the histograms measured at the end of SCP was 8+/-3 mmHg (p<0.001). SCP completely prevented the deep hypothermic circulatory arrest-dependent increase in extracellular dopamine and hydroxyl radicals. After SCP, there was a statistically significant increase in pCREB immunoreactivity (534+/-60%) compared to the sham-operated group (100+/-63%, p<0.005). Measurements of total CREB showed that SCP did induce a statistically significant increase in CREB as compared to sham-operated animals (168+/-31%, p<0.05). CONCLUSION: SCP, as compared to DHCA, improved cortical oxygenation and prevented increases in the extracellular dopamine and hydroxyl radicals. The increase in pCREB in the striatum following SCP may contribute to improved cellular recovery after this procedure.

Brain oxygenation and metabolism during repetitive apnea with resuscitation of 21% and 100% oxygen in newborn piglets.

The oxygen distribution in the microcirculation of the piglet's brain and striatal extracellular dopamine were determined during repetitive apnea and resuscitation with 21% or 100% oxygen. Pre-apnea cortical oxygen was 49.5+/-10.4 mm Hg and during each apnea decreased to 8+/-0.9 mm Hg. After ten apneic episodes followed by resuscitation with 21% or 100% oxygen, 7.48+/-1.6% or 2.6+/-0.5% of the tissue volume was below 10 mm Hg, respectively. Extracellular dopamine increased progressively with an increase in the number of apneas with resuscitation of 21% oxygen and at the end of ten apneic episodes it was up to 59,500+/-11,320% of control. There was no increase in extracellular dopamine during apnea resuscitated with 100% oxygen. Repetitive apnea caused progressive increase in fraction of hypoxic brain tissue in newborn. The magnitude of the increase is dependent on whether the animals were resuscitated with room air or 100% oxygen.

Circulatory arrest and low-flow cardiopulmonary bypass alter CREB phosphorylation in piglet brain.

BACKGROUND: The purpose of this study was to determine the effects of low-flow cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest followed by postbypass recovery on the phosphorylation state of transcription factor, cyclic adenosine 3', 5'-monophosphate response element-binding protein (CREB), in the striatum of neonatal brain. METHODS: Neonatal piglets (1.4 to 2.5 kg) anesthetized with isoflurane and fentanyl were put on CPB. The animals were cooled to 18 degrees C during a 20-minute period. The CPB circuit flow was then either reduced to 20 mL.kg(-1).min(-1) for 90 minutes (low-flow CPB) or turned off for 90 minutes (deep hypothermic circulatory arrest), following with a gradual increase in the flow and rewarming during a 30-minute period and a 2-hour recovery. At the end of the recovery period, the animals were rapidly euthanized, and the striata were removed and frozen for immunochemical analysis by Western blot technique using antibodies against phosphorylated and total CREB. The results are presented as mean +/- standard deviation (p < 0.05 was significant). RESULTS: Deep hypothermic circulatory arrest did not result in alteration in either the level of CREB or its degree of phosphorylation in the piglet striatum whereas after low-flow CPB, CREB phosphorylation was significantly increased (p < 0.005) and there was also an increase in CREB expression (p < 0.01). CONCLUSIONS: This study indicates that at 2 hours of recovery, low-flow CPB but not deep hypothermic circulatory arrest causes an increase in CREB phosphorylation and expression. Future studies will determine the degree to which the increase in CREB phosphorylation correlates with cell survival and neuronal injury after CPB.

CREB phosphorylation following hypoxia and ischemia in striatum of newborn piglets: possible role of dopamine.

The goal of the present study was to determine the effects of hypoxia and ischemia and the role of dopamine on phosphorylation of cAMP response element binding protein (CREB) in striatum of newborn piglets. Piglets, with and without prior injection of alpha-methyl-p-tyrosine (AMT), an inhibitor of dopamine (DA) synthesis, were subjected to 1 h of hypoxia (decreased inspired oxygen pressure, FiO2, from 21 to 6%) or 1 h of ischemia (ligation of both carotid arteries and hemorrhage to reduce the systemic arterial pressure to about 40 mmHg), followed by 2 h recovery. Microvascular oxygen pressure in the cortex (pCO2) was measured by quenching of phosphorescence. Extracellular DA was determined by in vivo microdialysis. Striatal levels of phosphorylated CREB (pCREB) and total CREB were determined by Western blots. In sham-operated animals, pCO2 was 49.7 +/- 8.2 mmHg. During hypoxia and ischemia, pCO2 decreased to 6.3 +/- 1.8 mmHg and 10.2 +/- 2.7 mmHg, respectively. There was statistical difference in the level of extracellular DA during hypoxia versus ischemia. At the end of ischemia and hypoxia, the levels of DA were 96 x 10(3) +/- 24 x 10(3)% and 26 x 10(3) +/- 12 x 10(3)% of control, respectively. The pCREB measured after 2 h recovery was not changed after hypoxia but was decreased to 47.8 +/- 24% of control after ischemia. Depletion of endogenous DA abolished the ischemia-induced decrease in pCREB level. Total CREB did not change after either condition. It can be concluded that observed decreases of CREB phosphorylation following ischemia can be at least partially due to the high extracellular DA level.