Liposomal Bupivacaine Transversus Abdominis Plane Blocks in Laparoscopic Colorectal Resections: A Single-Institution Randomized Controlled Trial.

BACKGROUND: Transversus abdominis plane blocks improve postoperative pain after colon and rectal resections, but the benefits of liposomal bupivacaine use for these blocks have not been clearly demonstrated. OBJECTIVE: This study aimed to determine whether using liposomal bupivacaine in transversus abdominis plane blocks improves postoperative pain and reduces opioid use after colorectal surgery compared to standard bupivacaine. DESIGN: This study was a single-blinded, single-institution, prospective randomized controlled trial comparing liposomal bupivacaine to standard bupivacaine in transversus abdominis plane blocks in patients undergoing elective colon and rectal resections. SETTINGS: This study was conducted at a single-institution academic medical center with 6 staff colorectal surgeons and 2 colorectal surgery fellows. PATIENTS: Ninety-six patients aged 18 to 85 years were assessed for eligibility; 76 were included and randomly assigned to 2 groups of 38 patients. INTERVENTIONS: Patients in the experimental group received liposomal bupivacaine transversus abdominis plane blocks, whereas the control group received standard bupivacaine blocks. MAIN OUTCOME MEASURES: The primary outcome was maximum pain score on postoperative day 2. Secondary outcomes included daily maximum and average pain scores in the 3 days after surgery, as well as daily morphine milligram equivalent use and length of hospital stay. RESULTS: Patients receiving liposomal bupivacaine blocks had lower maximum pain scores on the day of surgery (mean, 6.5 vs 7.7; p = 0.008). No other difference was found between groups with respect to maximum or average pain scores at any time point postoperatively, nor was there any difference in morphine milligram equivalents used or length of stay (median, 3.1 d). LIMITATIONS: This was a single-institution study with only patients blinded to group assignment. CONCLUSIONS: Liposomal bupivacaine use in transversus abdominis plane blocks for patients undergoing laparoscopic colorectal resections does not seem to improve postoperative pain, nor does it reduce narcotic use or decrease length of stay. Given its cost, use of liposomal bupivacaine in transversus abdominis plane blocks is not justified for colon and rectal resections. See Video Abstract at http://links.lww.com/DCR/B979 . CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov . Identifier: NCT04781075. BLOQUEOS TAP DE BUPIVACANA LIPOSOMAL EN RESECCIONES COLORRECTALES LAPAROSCPICAS UN ENSAYO CONTROLADO ALEATORIO DE UNA SOLA INSTITUCIN: ANTECEDENTES:Los bloqueos del plano transverso del abdomen, mejoran el dolor posoperatorio después de las resecciones de colon y recto, pero los beneficios del uso de bupivacaína liposomal para estos bloqueos, no se han demostrado claramente.OBJETIVO:Investigar la eficacia de la inyección con tejido adiposo autólogo recién recolectado en fístulas anales criptoglandulares complejas.DISEÑO:Ensayo controlado, aleatorio, prospectivo, simple ciego, de una sola institución, que compara la bupivacaína liposomal con la bupivacaína estándar en bloqueos del plano transverso del abdomen, en pacientes sometidos a resecciones electivas de colon y recto. Identificador de ClinicalTrials.gov : NCT04781075.ENTORNO CLINICO:Centro médico académico de una sola institución con seis cirujanos de plantilla y becarios de cirugía colorrectal.PACIENTES:Se evaluó la elegibilidad de 96 pacientes de 18 a 85 años; 76 fueron incluidos y aleatorizados en dos grupos de 38 pacientes.INTERVENCIONES:Los pacientes del grupo experimental recibieron bloqueos del plano transverso del abdomen con bupivacaína liposomal, mientras que el grupo de control recibió bloqueos de bupivacaína estándar.PRINCIPALES MEDIDAS DE VALORACION:El resultado primario fue la puntuación máxima de dolor en el segundo día posoperatorio. Los resultados secundarios incluyeron las puntuaciones máximas y medias diarias de dolor en los 3 días posteriores a la cirugía, así como el uso diario equivalente en miligramos de morfina y la duración de la estancia hospitalaria.RESULTADOS:Los pacientes que recibieron bloqueos de bupivacaína liposomal, tuvieron puntuaciones máximas de dolor más bajas, el día de la cirugía (media 6,5 frente a 7,7, p = 0,008). No hubo ninguna otra diferencia entre los grupos con respecto a las puntuaciones de dolor máximas o promedio en cualquier momento después de la operación, ni hubo ninguna diferencia en los equivalentes de miligramos de morfina utilizados o la duración de la estancia (mediana de 3,1 días).LIMITACIONES:Estudio de una sola institución con cegamiento de un solo paciente.CONCLUSIONES:El uso de bupivacaína liposomal en bloqueos del plano transverso del abdomen, para pacientes sometidos a resecciones colorrectales laparoscópicas, no parece mejorar el dolor posoperatorio, ni reduce el uso de narcóticos ni la duración de la estancia hospitalaria. Dado su costo, el uso de bupivacaína liposomal en bloqueos TAP no está justificado para resecciones de colon y recto. Consulte Video Resumen en http://links.lww.com/DCR/B797 . Traducción Dr. Fidel Ruiz Healy.

Genetic and Pharmacological Disruption of Interleukin-1α Leads to Augmented Murine Aortic Aneurysm.

BACKGROUND: Interleukin-1 (IL-1) signaling has an established role as a cytokine signaling pathway important for progression of abdominal aortic aneurysms (AAAs). While the IL-1ß ligand and IL-1R1 have been previously investigated, the role of the IL-1α ligand in AAAs remains unknown. In this study, we sought to examine the role of IL-1α in AAAs using genetic and pharmacologic approaches. METHODS: Eight-week-old wild-type (WT) or IL-1α knock-out (KO) male and female mice (n = 10-16/group) underwent experimental AAA and were harvested 14 days following surgery to assess AAA size and characteristics. In separate studies, 8-week-old WT mice were treated with an inhibitor to IL-1α during AAA formation and harvested 14 days following surgery. Finally, WT and IL-1α KO mice were administered Anakinra, an IL-R1 inhibitor, during AAA formation to determine the effect of inhibiting IL-1R1 when IL-1α is knocked out. RESULTS: Male and female IL-1α KO mice had larger AAAs compared to WT AAAs (male: 153% vs. 89.2%, P = 0.0001; female: 86.6% vs. 63.5%, P = 0.02). IL-1α KO mice had greater elastin breakage (P = 0.01), increased levels of macrophage staining (P = 0.0045), and greater pro-metallo proteinase 2 (P = 0.02). Pharmacologic inhibition of WT male mice with an IL-1α neutralizing antibody resulted in larger AAAs (133.1% vs. 77.0%, P < 0.001). Finally, treatment of IL-1α KO male mice with Anakinra decreased AAA formation compared with vehicle control AAAs (Anakinra + IL-1α KO: 47.7% vs. WT: 147.1%; P = 0.0001). CONCLUSIONS: IL-1α disruption using either genetic or pharmacologic approaches worsens AAAs.

Porcine Model of Infrarenal Abdominal Aortic Aneurysm.

Large animal models to study abdominal aortic aneurysms are sparse. The purpose of this model is to create reproducible, clinically significant infrarenal abdominal aortic aneurysms (AAA) in swine. To achieve this, we use a combination of balloon angioplasty, elastase and collagenase, and a lysyl oxidase inhibitor, called ß-aminopropionitrile (BAPN), to create clinically significant infrarenal aortic aneurysms, analogous to human disease. Noncastrated male swine are fed BAPN for 7 days prior to surgery to achieve a steady state in the blood. A midline laparotomy is performed and the infrarenal aorta is circumferentially dissected. An initial measurement is recorded prior to aneurysm induction with a combination of balloon angioplasty, elastase (500 units)/collagenase (8000 units) perfusion, and topical elastase application. Swine are fed BAPN daily until terminal procedure on either postoperative day 7, 14, or 28, at which time the aneurysm is measured, and tissue procured. BAPN + surgery pigs are compared to pigs that underwent surgery alone. Swine treated with BAPN and surgery had a mean aortic dilation of 89.9% ± 47.4% at day 7, 105.4% ± 58.1% at day 14, and 113.5% ± 30.2% at day 28. Pigs treated with surgery alone had significantly smaller aneurysms compared to BAPN + surgery animals at day 28 (p < 0.0003). The BAPN + surgery group had macroscopic and immunohistochemical evidence of end stage aneurysmal disease. Clinically significant infrarenal AAA can be induced using balloon angioplasty, elastase/collagenase perfusion and topical application, supplemented with oral BAPN. This model creates large, clinically significant AAA with hallmarks of human disease. This has important implications for the elucidation of AAA pathogenesis and testing of novel therapies and devices for the treatment of AAA. Limitations of the model include variation in BAPN ingested by swine, quality of elastase perfusion, and cost of BAPN.

Murine Surgical Model of Topical Elastase Induced Descending Thoracic Aortic Aneurysm.

According to the Center for Disease Control, aortic aneurysms (AAs) were considered a leading cause of death in all races and both sexes from 1999-2016. An aneurysm forms as a result of progressive weakening and eventual dilation of the aorta, which can rupture or tear once it reaches a critical diameter. Aneurysms of the descending aorta in the chest, called descending thoracic aortic aneurysms (dTAA), make up a large proportion of aneurysm cases in the United States. Uncontained dTAA rupture is almost universally lethal, and elective repair has a high rate of morbidity and mortality. The purpose of our model is to study dTAA specifically, to elucidate the pathophysiology of dTAA and to search for molecular targets to halt the growth or reduce the size of dTAA. By having a murine model to study thoracic pathology precisely, targeted therapies can be developed to specifically test dTAA. The method is based on the placement of porcine pancreatic elastase (PPE) directly on the outer murine aortic wall after surgical exposure. This creates a destructive and inflammatory reaction, which weakens the aortic wall and allows for aneurysm formation over weeks to months. Though murine models possess limitations, our dTAA model produces robust aneurysms of predictable size. Furthermore, this model can be used to test genetic and pharmaceutical targets which may arrest dTAA growth or prevent rupture. In human patients, interventions such as these could help avoid aneurysm rupture, and difficult surgical intervention.

A novel swine model of abdominal aortic aneurysm.

OBJECTIVE: Few large-animal models exist for the study of aortic aneurysms. ß-Aminopropionitrile (BAPN) is a compound known to cause aortic aneurysms by inhibiting lysyl oxidase, a collagen cross-linking enzyme. It is hypothesized that BAPN plus aneurysm induction surgery would result in significant aneurysm formation in swine with biologic properties similar to human disease. METHODS: Initial experiments were performed in uncastrated male swine not treated with BAPN (surgery alone). Subsequently, uncastrated male swine were fed BAPN (0.15 g/kg) for 7 days before undergoing surgery; the infrarenal aorta was circumferentially dissected and measured, balloon dilated, and perfused with elastase (500 units) and type I collagenase (8000 units), with extraluminal elastase application. In the BAPN groups, daily BAPN feedings continued until swine harvest at postoperative days 7, 14, and 28. RESULTS: Swine undergoing surgery alone (n = 12) had significantly less dilation at 28 days compared with BAPN + surgery swine (51.9% ± 29.2% [0%-100%] vs 113.5% ± 30.2% [52.9%-146.2%]; P < .0003). Mean aortic dilation in animals undergoing treatment with surgery and BAPN was 86.9% ± 47.4% (range, 55.6%-157.1%), 105.4% ± 58.1% (50%-133.3%), and 113.5% ± 30.2% (52.9%-146.2%) at 7, 14, and 28 days, respectively. In the BAPN + surgery group, significant elastolysis was present at all time points, whereas aortic wall collagen content was not significantly different. Smooth muscle cells were significantly depleted at 14 and 28 days, and M1 macrophages were increased at 14 and 28 days (P < .05, all). Matrix metalloproteinase 2 was elevated at 7 days (P < .05). Multiple proinflammatory cytokines were elevated within the aortic wall of BAPN + surgery swine. CONCLUSIONS: BAPN plus surgery resulted in significantly larger aortic aneurysms than surgery alone and was critical to aneurysm formation in this novel swine model. Hallmarks of human disease, such as elastin fragmentation, smooth muscle cell depletion, macrophage infiltration, matrix metalloproteinase activation, and proinflammatory cytokine expression, were observed in BAPN-treated swine. This model better parallels many of the characteristics of human AAAs and may be suitable for prehuman drug trials.

What Is the Risk of Anastomotic Leak After Repeat Intestinal Resection in Patients With Crohn's Disease?

BACKGROUND: Approximately half of Crohn's patients require intestinal resection, and many need repeat resections. OBJECTIVE: The purpose of this study was to evaluate the increased risk of clinical anastomotic leak in patients with a history of previous intestinal resection undergoing repeat resection with anastomosis for Crohn's disease. DESIGN: This was a retrospective analysis of prospectively collected departmental data with 100% capture. SETTINGS: The study was conducted at the department of colorectal surgery in a tertiary care teaching hospital between July 2007 and March 2016. PATIENTS: A cohort of consecutive patients with Crohn's disease who were treated with intestinal resection and anastomosis, excluding patients with proximal fecal diversion, were included. The cohort was divided into 2 groups, those with no previous resection compared with those with previous resection. MAIN OUTCOME MEASURES: Clinical anastomotic leak within 30 days of surgery was measured. RESULTS: Of the 206 patients who met criteria, 83 patients had previous intestinal resection (40%). The 2 groups were similar in terms of patient factors, immune-suppressing medication use, and procedural factors. Overall, 20 clinical anastomotic leaks were identified (10% leak rate). There were 6 leaks (5%) detected in patients with no previous intestinal resection and 14 leaks (17%) detected in patients with a history of previous intestinal resection (p < 0.005). The OR of anastomotic leak in patients with Crohn's disease with previous resection compared with no previous resection was 3.5 (95% CI, 1.3-9.4). Patients with 1 previous resection (n = 53) had a leak rate of 13%, whereas patients with ≥2 previous resections (n = 30) had a leak rate of 23%. The number of previous resections correlated with increasing risk for clinical anastomotic leak (correlation coefficient = 0.998). LIMITATIONS: This was a retrospective study with limited data to perform a multivariate analysis. CONCLUSIONS: Repeat intestinal resection in patients with Crohn's disease is associated with an increased rate of anastomotic leakage when compared with initial resection despite similar patient, medication, and procedural factors. See Video Abstract at http://links.lww.com/DCR/A459.