Intraoperative Epiphyseal Perfusion Monitoring Does Not Reliably Predict Osteonecrosis Following Treatment of Unstable SCFE.

BACKGROUND: Avascular necrosis (AVN) remains the most dreaded complication of unstable slipped capital femoral epiphysis (SCFE) treatment. Newer closed reduction techniques (with perfusion monitoring) have emerged as a technically straightforward means to address residual SCFE deformity while still minimizing the risk of osteonecrosis. However, limited data exists regarding the reliability of intraoperative epiphyseal perfusion monitoring to predict the development of AVN. The purpose of this study was to evaluate its reliability. METHODS: We retrospectively reviewed all patients with unstable SCFE who underwent closed or open reduction with epiphyseal perfusion monitoring using an intracranial pressure (ICP) probe from 2015 to 2023 at a single institution with a minimum 6-month radiographic follow-up. Demographic, clinical, and radiographic data were recorded, including duration of symptoms, type of reduction, capsulotomy performed, presence of a waveform on ICP monitoring after epiphyseal fixation, and development of AVN on follow-up radiographs. RESULTS: Our cohort included 33 hips (32 patients), of which 60.6% (n=20) were male. The average age was 12.5±1.8 years, with a median follow-up of 15.8 months. Eleven hips were treated with open reduction using the modified Dunn technique (10 hips) or anterior approach (1 hip), and 22 hips were treated with inadvertent (5 hips) or purposeful closed reduction using the Leadbetter technique (17 hips). Overall, 8 of the 33 hips in our series (24.2%) developed AVN, 6 of which (20%) had a pulsatile waveform on intraoperative epiphyseal perfusion monitoring. The overall rate of AVN after closed reductions was 31.8% (7 of 22 hips); the incidence of AVN after closed reduction with a detectable waveform was 30% (6 of 20 hips). There was no significant association between time to surgery ( P =0.416) or type of reduction ( P =0.218) and the incidence of AVN. CONCLUSIONS: In this series, intraoperative epiphyseal perfusion monitoring did not reliably predict the development of osteonecrosis. To our knowledge, this is the first study to report AVN after demonstrable intraoperative epiphyseal perfusion following closed reduction of unstable slips. LEVEL OF EVIDENCE: Level IV: case series-therapeutic study.

Can a Therapeutic Strategy for Hypotension Improve Cerebral Perfusion and Oxygenation in an Experimental Model of Hemorrhagic Shock and Severe Traumatic Brain Injury?

BACKGROUND: Restoration of brain tissue perfusion is a determining factor in the neurological evolution of patients with traumatic brain injury (TBI) and hemorrhagic shock (HS). In a porcine model of HS without neurological damage, it was observed that the use of fluids or vasoactive drugs was effective in restoring brain perfusion; however, only terlipressin promoted restoration of cerebral oxygenation and lower expression of edema and apoptosis markers. It is unclear whether the use of vasopressor drugs is effective and beneficial during situations of TBI. The objective of this study is to compare the effects of resuscitation with saline solution and terlipressin on cerebral perfusion and oxygenation in a model of TBI and HS. METHODS: Thirty-two pigs weighing 20-30 kg were randomly allocated into four groups: control (no treatment), saline (60 ml/kg of 0.9% NaCl), terlipressin (2 mg of terlipressin), and saline plus terlipressin (20 ml/kg of 0.9% NaCl + 2 mg of terlipressin). Brain injury was induced by lateral fluid percussion, and HS was induced through pressure-controlled bleeding, aiming at a mean arterial pressure (MAP) of 40 mmHg. After 30 min of circulatory shock, resuscitation strategies were initiated according to the group. The systemic and cerebral hemodynamic and oxygenation parameters, lactate levels, and hemoglobin levels were evaluated. The data were subjected to analysis of variance for repeated measures. The significance level established for statistical analysis was p < 0.05. RESULTS: The terlipressin and saline plus terlipressin groups showed an increase in MAP that lasted until the end of the experiment (p < 0.05). There was a notable increase in intracranial pressure in all groups after starting treatment for shock. Cerebral perfusion pressure and cerebral oximetry showed no improvement after hemodynamic recovery in any group. The groups that received saline at resuscitation had the lowest hemoglobin concentrations after treatment. CONCLUSIONS: The treatment of hypotension in HS with saline and/or terlipressin cannot restore cerebral perfusion or oxygenation in experimental models of HS and severe TBI. Elevated MAP raises intracranial pressure owing to brain autoregulation dysfunction caused by TBI.

Perfusion-Dependent Focal Neurologic Deficits in a Critically Ill Heart Transplant Recipient: A Case of Tacrolimus-Associated Reversible Cerebral Vasospasm Syndrome?

TACROLIMUS, a mainstay of immunosuppression after orthotopic heart transplantation (OHT), is associated with a broad range of side effects. Vasoconstriction caused by tacrolimus has been proposed as a mechanism underlying common side effects such as hypertension and renal injury. Neurologic side effects attributed to tacrolimus include headaches, posterior reversible encephalopathy syndrome (PRES), or reversible cerebral vasospasm syndrome (RCVS). Six case reports have been published describing RCVS in the setting of tacrolimus administration after OHT. The authors report a case of perfusion-dependent focal neurologic deficits attributed to tacrolimus-induced RCVS in an OHT recipient.

Optimal circulatory arrest temperature for aortic hemiarch replacement with antegrade brain perfusion.

OBJECTIVE: This study sought to identify the optimal temperature for moderate hypothermic circulatory arrest in patients undergoing elective hemiarch replacement with antegrade brain perfusion. METHODS: The Society of Thoracic Surgeons adult cardiac surgery database was queried for elective hemiarch replacements using antegrade brain perfusion for aneurysmal disease (2014-2019). Generalized estimating equations and restricted cubic splines were used to determine the risk-adjusted relationships between temperature as a continuous variable and outcomes. RESULTS: Elective hemiarch replacement with antegrade brain perfusion occurred in 3898 patients at 374 centers with a median nadir temperature of 24.9°C (first quartile, third quartile = 22.0°C, 27.5°C) and median circulatory arrest time of 19 minutes (first quartile, third quartile = 14.0 minutes, 27.0 minutes). After adjustment for comorbidities, circulatory arrest time, and individual surgeon, patients cooled between 25 and 28°C had an early survival advantage compared with 24°C, whereas those cooled between 21 and 23°C had higher risks of mortality compared with 24°C. A nadir temperature of 27°C was associated with the lowest risk-adjusted odds of mortality (odds ratio, 0.62; 95% confidence interval, 0.42-0.91). A nadir temperature of 21°C had the highest risk of mortality (odds ratio, 1.4; 95% confidence interval, 1.13-1.73). Risk of experiencing a major morbidity was elevated in patients cooled between 21 and 23°C, with the highest risk occurring in patients cooled to 21°C (odds ratio, 1.12; 95% confidence interval, 1.01-1.24). CONCLUSIONS: For patients with aneurysmal disease undergoing elective hemiarch with antegrade brain perfusion, circulatory arrest with a nadir temperature of 27°C confers the greatest early survival benefit and smallest risk of postoperative morbidity.

Acute Limb Ischemia After Self-Injection of Crushed Morphine Tablets into the Radial Artery: Role of Infrared Thermography in the Assessment of Tissue Perfusion.

BACKGROUND This article presents a case involving complications after intentional injection of crushed tablets into the arterial circulation, its diagnosis, and the treatment adopted. The diagnosis process illustrates the potential of techniques based on thermal imaging as tools to assess tissue perfusion. Inadvertent intravenous injection of crushed tablets is more common, but there are few reports on arterial circulation, and no studies were found on the self-injection of crushed morphine tablets, particularly into the radial artery. CASE REPORT A 51-year-old man with alcoholism and a history of illegal drug usage intentionally self-injected 3 crushed morphine tablets into his right radial artery. The patient progressed with compartment syndrome, requiring decompressive fasciotomy of the right forearm and ischemia of the right fingers, which were amputated. He presented with rhabdomyolysis and required dialysis. The patient agreed to full heparinization, corticotherapy, and the use of nitroglycerin and prostaglandin E1. Due to the progression of the necrotic area, the patient underwent proximal phalanx excision and surgical reconstruction of the right-hand remnant. CONCLUSIONS The injection of morphine tablets into circulation caused severe complications, which led to the excision of the proximal phalanx and the surgical reconstruction of the remnant of the right hand. In the present case, infrared thermography proved to be an effective method in assessing tissue perfusion.

Current and future perspectives on acute-on-chronic liver failure: Challenges of transplantation, machine perfusion, and beyond.

Acute-on-chronic liver failure (ACLF) is a syndrome that occurs in patients with chronic liver disease and is characterized by acute decompensation, organ failure and high short-term mortality. Partially due to the lack of universal diagnostic criteria, the actual ACLF prevalence remains unclear; nevertheless, it is expected to be a highly prevalent condition worldwide. Earlier transplantation is an effective protective measure for selected ACLF patients. Besides liver trans-plantation, diagnosing and treating precipitant events and providing supportive treatment for organ failures are currently the cornerstone of ACLF therapy. Although new clinical specific therapies have been researched, more studies are necessary to assess safety and efficacy. Therefore, future ACLF management strategies must consider measures to improve access to liver transplantation because the time window for this life-saving therapy is frequently narrow. Thus, an urgent and global discussion about allocation and prioritization for transplantation in critically ill ACLF patients is needed because there is evidence suggesting that the current model may not portray their waitlist mortality. In addition, while donor organ quality is meant to be a prognostic factor in the ACLF setting, recent evidence suggests that machine perfusion of the liver may be a safe tool to improve the donor organ pool and expedite liver transplantation in this scenario.

Randomized Trial of Perfusion-Based Circulatory Management in Infants of Very Low Birth Weight.

OBJECTIVE: To establish the superiority of blood flow (BF)-based circulatory management over conventional blood pressure (BP)-based management strategies used for preventing intraventricular hemorrhage (IVH) in infants of very low birth weight (VLBW). STUDY DESIGN: We conducted a nonblinded, single-centered randomized trial with the aim to prevent IVH by managing BF. Infants with VLBW were assigned randomly to a BF-based group or BP-based (BP group) circulatory management group. The incidence of IVH was the outcome of interest. The IVH also data were compared among healthy patients and patients responsive and unresponsive to the intervention. RESULTS: A total of 219 and 220 infants with VLBW were assigned to the BF and BP groups, respectively. The IVH incidence rate was lower in the BF group, but the difference was not statistically significant (BF group, 6.8% vs BP group, 10.9%; P = .14). In 21% of patients of the BP group and 20% of the BF group, the intervention failed. In BF group, the IVH incidence rate was significantly greater in infants with unsuccessful intervention when compared with healthy individuals (6% vs 23%, P = .001). Multivariate logistic regression analysis revealed a correlation between low blood flow and IVH (aOR 3.24; 95% CI 1.49-7.08, P = .003) but not between low BP and IVH (P = .73). CONCLUSIONS: The BF management protocol did not significantly decrease the incidence of IVH. However, after further optimization, we speculate the treatment strategy holds promise in decreasing the incidence of IVH. Trial registration UMIN-CTR: UMIN000013296.

Arterial protocol including prophylactic distal perfusion catheter decreases limb ischemia complications in patients undergoing extracorporeal membrane oxygenation.

OBJECTIVE: Venoarterial extracorporeal membrane oxygenation (ECMO) is a salvage therapy in patients with severe cardiopulmonary failure. Owing to the large size of the cannulas inserted via the femoral vessels (≤24-F) required for adequate oxygenation, this procedure could result in significant limb ischemic complications (10%-70%). This study evaluates the results of a distal limb perfusion arterial protocol designed to reduce associated complications. METHODS: We conducted a retrospective institutional review board-approved review of consecutive patients requiring ECMO via femoral cannulation (July 2010-January 2015). To prevent arterial ischemia, a distal perfusion catheter (DPC) was placed antegrade into the superficial femoral artery and connected to the ECMO circuit. Limb perfusion was monitored via near-infrared spectroscopy (NIRS) placed on both calves. Decannulation involved open repair, patch angioplasty, and femoral thrombectomy as needed. RESULTS: A total of 91 patients were placed on ECMO via femoral arterial cannula (16-F to 24-F) for a mean duration of 9 days (range, 1-40 days). A percutaneous DPC was inserted prophylactically at the time of cannulation in 55 of 91 patients, without subsequent ischemia. Of the remaining 36 patients without initial DPC placement, 12 (33% without DPC) developed ipsilateral limb ischemia related to arterial insufficiency, as detected by NIRS and clinical findings. In these patients, the placement of a DPC (n = 7) with or without a fasciotomy, or with a fasciotomy alone (n = 4), resulted in limb salvage; only one patient required subsequent amputation. After decannulation (n = 7), no patients had further evidence of limb ischemia. Risk factors for the development of limb ischemia identified by categorical analysis included lack of DPC at time of cannulation and ECMO cannula size of less than 20-Fr. There was a trend toward younger patient age. Overall ECMO survival rate was 42%, whereas survival in patients with limb ischemia was only 25%. CONCLUSIONS: Limb ischemia complications from ECMO may be decreased by prophylactic placement of an antegrade DPC. Without DPC, continuous monitoring using NIRS may identify limb ischemia, which can be treated subsequently with DPC and or fasciotomy.

Direct innominate artery cannulation: An alternate technique for antegrade cerebral perfusion during aortic hemiarch reconstruction.

OBJECTIVE: We describe an alternate technique for establishing antegrade cerebral perfusion (ACP) during hypothermic circulatory arrest via direct, central cannulation of the innominate artery. METHODS: From 2009 to 2015, 100 elective hemiarch reconstructions for proximal aortic aneurysms were performed under moderate hypothermic circulatory arrest (MHCA). Cerebral perfusion was instituted with ACP via direct cannulation of the innominate artery. RESULTS: Mean patient age was 63 ± 13 years (72 men; 72%). Mean MHCA temperature was 27.3°C ± 1.0°C (median, 28°C). Mean ACP time was 17 ± 4 minutes and mean crossclamp time was 134 ± 42 minutes. Proximal reconstruction included root replacement with composite valved graft (n = 47), valve sparing root reimplantation (n = 16), and aortic valve replacement (n = 19). In-hospital 30-day mortality (n = 1; 1%), stroke (1; 1%), reversible ischemic neurologic deficit (n = 1; 1%), coma (n = 0), and renal failure (n = 1; 1%) rates were low. There was no incidence of injury or dissection of the innominate artery. CONCLUSIONS: Direct, central innominate artery cannulation for ACP yields excellent outcomes. This technique is safe, provides excellent cerebral protection during circulatory arrest and simplifies the circulatory management strategy for elective ascending aortic and hemiarch reconstruction.

Cognitive deficits in Machado-Joseph disease correlate with hypoperfusion of visual system areas.

Cognitive and olfactory impairments have previously been demonstrated in patients with spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease (MJD)-SCA3/MJD. We investigated changes in regional cerebral blood flow (rCBF) using single-photon emission computed tomography (SPECT) imaging in a cohort of Brazilian patients with SCA3/MJD. The aim of the present study was to evaluate the correlation among rCBF, cognitive deficits, and olfactory dysfunction in SCA3/MJD. Twenty-nine genetically confirmed SCA3/MJD patients and 25 control subjects were enrolled in the study. The severity of cerebellar symptoms was measured using the International Cooperative Ataxia Rating Scale and the Scale for the Assessment and Rating of Ataxia. Psychiatric symptoms were evaluated by the Hamilton Anxiety Scale and Beck Depression Inventory. The neuropsychological assessment consisted of Spatial Span, Symbol Search, Picture Completion, the Stroop Color Word Test, Trail Making Test (TMT), and Phonemic Verbal Fluency. Subjects were also submitted to odor identification evaluation using the 16-item Sniffin' Sticks. SPECT was performed using ethyl cysteine dimer labeled with technetium-99m. SCA3/MJD patients showed reduced brain perfusion in the cerebellum, temporal, limbic, and occipital lobes compared to control subjects (pFDR <0.001). A significant positive correlation was found between the Picture Completion test and perfusion of the left parahippocampal gyrus and basal ganglia in the patient group as well as a negative correlation between the TMT part A and bilateral thalamus perfusion. The visuospatial system is affected in patients with SCA3/MJD and may be responsible for the cognitive deficits seen in this disease.

Perfusion fluid contamination in relation to recipient survival and acute cellular rejection in orthotopic liver transplantation: retrospective analysis.

INTRODUCTION: A perfusion fluid used in the preservation of a grafted liver represents a medium suitable for microorganism growth. This study investigated the prevalence of perfusion fluid contamination, acute cellular rejection (ACR) episodes, and patient survival rate. METHOD: This is a retrospective study, based on an electronic database allocating cases of orthotopic liver transplantation. The exclusion criteria were as follows: having been submitted to multiple organ transplantation, liver retransplantation only, and those whose samples had not been collected or sent on the back table procedure or were unobtainable (usually the samples were sent when there was donor infection suspicion/positivity). Our posttransplantation infection prophylactic protocol consisted of ampicillin/sulbactam for 72 hours. The variables in the study were as follows: fluid contamination, presence of acute cellular rejection (ACR, Banff classification), and recipient survival at the first year. Statistical analysis was performed using descriptive statistics and chi-square with Fisher exact test considering significant P<.05. RESULTS: We observed perfusion fluid contamination in 15/121 (12.39%). The agents were as follows: Klebsiella pneumoniae in 6 (4.96%), Staphylococcus epidermidis in 5 (4.13%), and Acinetobacter baumanii in 3 (2.48%) and negative cultures in 106 (87.60%). Only 1 patient had matching for donor infection and positivity hemoculture after the transplantation (K pneumoniae) and he was the only patient associated with fluid infection and death. The recipients who had their fluid preservation with positive cultures had more ACR and the survival rate was similar among those with or without infection. CONCLUSION: Optimization of microbiological procedures can be performed including fungal and bacterial cultures.

Histologic alterations of rat kidneys perfused with a Euro-Collins diltiazem solution / Alterações histológicas ocorridas em rins de ratos perfundidos com solução de Euro-Collins associada à diltiazem

PURPOSE: Analyse the histologic changes of rat kidneys perfused with isotonic saline solution (ISS), Euro-Collins solution (ECS) and Euro-Collins solution with diltiazem (ECSD). METHODS: Thirty-six Wistar rats were used divided equally, as follow: group A (ISS), group B (ECS) and group C (ECSD). Through a catheter placed into the abdominal aorta, a renal perfusion was performed using a solution according to the group to which the animal belonged. After the complete perfusion, bilateral nephrectomy was performed and the organs were preserved under hypothermia for five distinct periods of time. Glomerulus and tubule were evaluated through optical microscopy. RESULTS: Renal perfusion with ECS and ECSD proved effectiveness in the preservation of the organs up to 36 hours and an increase in the percentage of injured glomeruli was noticed only in the period of 48 hours. CONCLUSIONS: The results showed that exists an association between the tubular injury and the glomeruli lesion degree; kidneys with a higher degree of tubular damage were related to severe glomerular lesion. Also, the addition of a calcium channel blocker, diltiazem, to the ECS for the renal perfusion does not decrease the percentage of glomerular lesion.(AU)

OBJETIVO: Analisar as alterações histológicas nos rins de ratos perfundidos com solução salina isotônica (ISS), solução Euro-Collins (ECS) e solução Euro-Collins com diltiazem (ECSD). MÉTODOS: Foram divididos, de forma igual, 36 ratos Wistar, como se segue: grupo A (ISS), grupo B (ECS), grupo C (ECSD). Através de um cateter localizado na aorta abdominal, foi realizada a perfusão renal com a solução de acordo com o grupo ao qual o animal pertencia. Após a perfusão total, realizou-se nefrectomia bilateral com a preservação dos órgãos sob hipotermia por cinco períodos distintos de tempo. Glomérulos e túbulos foram avaliados por microscopia óptica. RESULTADOS: Tanto a perfusão renal com ECS quanto a com ECSD provaram sua efetividade na preservação dos órgãos em até 36 horas e aumento da porcentagem de glomérulos injuriados foi notada apenas no período de 48 horas. CONCLUSÕES: Os resultados mostraram haver uma correlação entre a injúria tubular e o grau de lesão glomerular; rins com um maior grau de dano tubular foram relacionados com lesão glomerular severa. Além disso, a adição de um bloqueador de canal de cálcio, diltiazem, à ECS para a perfusão renal não diminui a porcentagem de lesão glomerular.(AU)

Síndrome vasoplégica: nova forma de síndrome pós perfusäo / Vasoplegia syndrome: a new form of postperfusion syndrome

Uma nova forma de síndrome pós perfusao, denominada síndrome vasoplégica, aparecendo no período pós-operatório imediato de cirurgias cardíacas com circulaçao extracorpórea (CEC) é apresentada. As manifestaçoes dessa síndrome incluem hipotensao, débito cardíaco normal ou aumentado, resistência vascular sistêmica diminuída e pressoes de enchimento baixas. O exame físico mostra que, mesmo com hipotensao, os pacientes apresentam bom enchimento capilar de extremidades, mas com oligúria. Há necessidade de uso de vasoconstrictores potentes para manutençao da pressao arterial e, mesmo com altas doses de noradrenalina, nao há o quadro clássico de extremidades frias. Doze pacientes que apresentaram sinais e sintomas compatíveis com a síndrome vasoplégica sao mostrados. O quadro da síndrome vasoplégica mostra semelhança com o observado no choque séptico. Na sepse, as alteraçoes sao mediadas pelas citocinas, entre elas o TNF-alpha, que também já foi demonstrado serem ativadas pela CEC. O aparecimento da síndrome vasoplégica eleva a morbidade operatória, com conseqüente aumento de risco para o paciente.

Injúria orgânica da circulaçäo extracorpórea nos três primeiros meses de vida / Organic injury of extracorporeal circulation in the 1st 3 months of life

Diversos fatores contribuíram para aumentar o número de procedimentos com circulaçao extracopórea para neonatos e lactentes. Esses pacientes necessitam procedimentos especiais de perfusao, fundamentos em sua fisiologia particular, nas características do seu metabolismo e na sua resposta aos desvios da homeostase, principalmente a acidose lática. Sao analisados os protocolos de perfusao em 110 procedimentos com parada circulatória total, para a realizaçao da correçao intracardíaca, durante a qual diversos mecanismos de injúria ao sangue foram identificados. A injúria mecânica, por açao das forças desenvolvidas na circulaçao artificial do sangue e nas trocas gasosas, pode danificar os elementos figurados e as proteínas do plasma sangüíneo. O contato com as superfícies do circuito extracorpóreo pode ativar os sistemas das cininas, da coagulaçao, da fibrinólise e do complemento, por ativaçao inicial do fator XII e produzir uma reaçao inflamatória generalizada. A produçao de ácido lático pode modificar o pH ideal para a funçao enzimática e celular, e o superaquecimento do sangue, durante o reaquecimento, pode produzir dano ao sangue semelhante àquele causado pelos fatores físicos da circulaçao extracorpórea. A perfusao neonatal e de pequenos lactentes é um continuado exercício de atençao aos detalhes e respeito aos aspectos particulares da fisiologia, do metabolismo e da resposta à injúria.

Arritmias cardíacas por reperfusión coronaria en el conejo / Cardiac arrhytmias by coronary reperfussion in the rabbit

Los avances recientes de la angiografía coronaria han permitido revelar los espasmos transitorios de la arteria coronaria y se ha podido estudiar la relación de este espasmo con la angina de Prinzmetal. Los mecanismos responsables de la aparición de las arritmias por reperfusión de una coronaria son estudiados y debatidos en los últimos años. En este trabajo se creó un modelo experimental de arritmias por reperfusión coronaria en el conejo y se evaluó la influencia que tiene la supresión vagal y simpática en este tipo de arritmias. Las arritmias por reperfusión que aparecían inmediatamente después de desocluir la coronaria eran arritmias ventriculares severas del tipo de latidos ventriculares prematuros aislados y múltiples, bigeminismo ventricular, taquicardia ventricular y fibrilación ventricular. De un grupo de 23 conejos que presentaron arritmia por oclusión coronaria, el 82,2% las presentó también en la reperfusión de la arteria ocluída, y de un grupo de 15 animales que no presentaron arritmia por oclusión, un 53% las presentaron en la reperfusión. En los animales vagotomizados y los animales tratados con propranolol (0,5 mg/Kg;i.v.) disminuyó la incidencia de arritmias por reperfusión coronaria. Se considera que el modelo experimental estudiado es útil para evaluar las arritmias cardíacas por reperfusión y que la supresión vagal, por un lado, y el bloqueo simpático por otro, disminuyen notablemente la frecuencia de aparición de estas arritmias