Better Outcomes if Percutaneous Drainage Is Used Early and Proactively in the Course of Necrotizing Pancreatitis.

PURPOSE: To compare outcomes after percutaneous catheter drainage (PCD) for acute necrotizing pancreatitis versus those in a randomized controlled trial as a reference standard. MATERIALS AND METHODS: Between September 2010 and August 2014, CT-guided PCD was the primary treatment for 39 consecutive patients with pancreatic necrosis. The indication for PCD was the clinical finding of uncontrolled pancreatic juice leakage rather than infected necrosis. Subsequent to PCD, the drains were proactively studied with fluoroscopic contrast medium every 3 days to ensure patency and position. Drains were ultimately maneuvered to the site of leakage. These 39 patients were compared with 43 patients from the Pancreatitis, Necrosectomy versus Step-up Approach (PANTER) trial. RESULTS: The CT severity index was similar between studies (median of 8 in each). Time from onset of acute pancreatitis to PCD was shorter in the present series (median, 23 d vs 30 d). The total number of procedures (PCD and subsequent fluoroscopic drain studies) per patient was greater in the present series (mean, 14 vs 2). More patients in the PANTER trial had organ failure (62% vs 84%), required open or endoscopic necrosectomy (0% vs 60%), and experienced in-hospital mortality (0% vs 19%; P < .05 for all). CONCLUSIONS: Even though patients in the present series had a similar CT severity index as those in the PANTER trial, the former group showed lower incidences of organ failure, need for necrosectomy, and in-hospital mortality. The use of a proactive PCD protocol early, before the development of severe sepsis, appeared to be effective.

A percutaneous drainage protocol for severe and moderately severe acute pancreatitis.

BACKGROUND: According to the revised Atlanta classification, severe and moderately severe acute pancreatitis (AP) includes patients with pancreatic and peripancreatic collections with or without organ failure. These collections suggest the presence of pancreatic juice leakage. The aim of this study was to evaluate the efficacy of a percutaneous catheter drainage (PCD) protocol designed to control leakage and decrease disease severity. METHODS: Among 663 patients with clinical AP, 122 were classified as moderately severe or severe AP (all had collections). The computed tomography severity index (CTSI) score was calculated. The indication for PCD was based on progressive clinical signs and symptoms. Drain patency, position, and need for additional drainage sites were assessed using CT scans and drain studies initially every 3 days using a proactive protocol. Drain fluid was examined for amylase concentration and microbiological culture. Clinicopathological variables for patients with and without PCD were compared. Since there was no mortality, we used prolonged drainage time to measure the success of PCD. Within the group treated with PCD, variables that resulted in prolonged drainage time were analyzed. RESULTS: PCD was used in 47/122 (39 %) patients of which 33/47 (70 %) had necrosis. PCD cases had a median CTSI of 8 and were classified as moderately severe AP (57 %) and severe AP (43 %). Inhospital mortality was zero. Surgical necrosectomy was not required for patients with necrosis. Independent risk factors for prolonged drainage time were persistent organ failure >48 h (P = 0.001), CTSI 8-10 (P = 0.038), prolonged duration of amylase-rich fluid in drains (P < 0.001), and polymicrobial culture fluid in drains (P = 0.015). CONCLUSIONS: A proactive PCD protocol persistently maintaining drain patency advanced to the site of leak controlled the prolonged amylase in drainage fluid resulting in a mortality rate of zero.

Association between major perioperative hemorrhage and stroke or Q-wave myocardial infarction.

BACKGROUND: Hemorrhage is associated with ischemic complications in cardiac patients. The nature of this relationship in surgical patients is unknown. METHODS AND RESULTS: We examined the association between major perioperative hemorrhage and stroke or myocardial infarction among adults who underwent surgery from 2005 through 2009 at centers participating in the National Surgical Quality Improvement Program. We excluded patients with emergent, trauma-related, transplantation, cardiac, or neurological operations. Major hemorrhage was defined as bleeding necessitating transfusion of >4 U of packed red blood cells or whole blood. Stroke was defined as focal brain dysfunction lasting ≥24 hours from a vascular cause. A diagnosis of myocardial infarction required new ECG Q waves. Outcomes were assessed from surgery until 30 days afterward. Among 651,775 patients who underwent surgery, 5233 (0.80%) experienced major hemorrhage, 1575 (0.24%) developed Q-wave myocardial infarction, and 1321 (0.20%) suffered a stroke. In Cox proportional hazards analyses controlling for vascular risk factors, illness severity, and type of surgery, hemorrhage was independently associated with subsequent stroke (hazard ratio, 2.5; 95% confidence interval, 1.9-3.3) and subsequent Q-wave myocardial infarction (hazard ratio, 2.7; 95% confidence interval, 2.1-3.4). Interaction terms revealed no significant variation in these associations by age, sex, or type of surgery. Our results were robust across multiple sensitivity analyses. CONCLUSIONS: Major perioperative hemorrhage is associated with subsequent stroke and myocardial infarction in patients undergoing noncardiac, nonneurological surgery. This suggests the need for randomized trials to guide perioperative use of antiplatelet drugs, which affect the risk of both bleeding and vascular events.

The impact of liposuction cannula size on adipocyte viability.

PURPOSE: Autologous fat transfer ("fat grafting") is widely used in cosmetic and reconstructive surgery, but long-term outcomes remain inconsistent. Each step in the transfer process can cause mechanical damage to the graft tissue. In particular, liposuction breaks aspirated adipose tissue into distinct globules and subjects it to shear forces, both of which can impact subsequent fat graft viability. The optimal size of the liposuction cannula for use in fat grafting is not known. METHODS AND TECHNIQUES: Controlled lipoaspirate samples were collected from adult female patients undergoing elective liposuction of the abdomen and flanks with uniform aspiration pressure (-25 in Hg) and either a 3- or 5-mm standard blunt-tip liposuction cannula. Individual grafts of 1.00±(0.01) gram were prepared and injected into the bilateral flanks of nude mice with a 14-gauge catheter. After six weeks, these grafts were explanted and analyzed by weight and histology. RESULTS: At six weeks, fat lobules in the 5-mm group retained 25% more weight than those in the 3-mm group [mean (SD), 0.70 (0.07) vs 0.56 (0.09) g, n=24/group, P<0.01). Histologic analysis revealed more intact, nucleated adipocytes in the 5-mm group than in the 3-mm group [4.42 (0.92) vs 3.10 (0.56) on a 1-5 rating scale]. The 5-mm group exhibited both less infiltrate [1.58 (0.17) vs 3.13 (0.70)] and less fibrosis [1.67 (0.45) vs 3.13 (0.89)] than the 3-mm group. CONCLUSIONS: In this controlled model of fat grafting with either a 5- or 3-mm aspiration cannula, the use of a larger aspiration cannula led to improved graft retention and quality. This finding has important implications for clinical applications of fat grafting.

Biliary Stenosis and Gastric Outlet Obstruction: Late Complications After Acute Pancreatitis With Pancreatic Duct Disruption.

OBJECTIVES: Pancreatic duct disruption (PDD) after acute pancreatitis can cause pancreatic collections in the early phase and biliary stenosis (BS) or gastric outlet obstruction (GOO) in the late phase. We aimed to document those late complications after moderate or severe acute pancreatitis. METHODS: Between September 2010 and August 2014, 141 patients showed pancreatic collections on computed tomography. Percutaneous drainage was primarily performed for patients with signs or symptoms of uncontrolled pancreatic juice leakage. Pancreatic duct disruption was defined as persistent amylase-rich drain fluid or a pancreatic duct cut-off on imaging. Clinical course of the patients who developed BS or GOO was investigated. RESULTS: Among the 141 patients with collections, 33 patients showed PDD in the pancreatic head/neck area. Among them, 9 patients (27%) developed BS 65 days after onset and required stenting for 150 days, and 5 patients (15%) developed GOO 92 days after onset and required gastric decompression and jejunal tube feeding for 147 days (days shown in median). All 33 patients recovered successfully without requiring surgical intervention. CONCLUSIONS: Anatomic proximity of the bile duct or duodenum to the site of PDD and severe inflammation seemed to contribute to the late onset of BS or GOO. Conservative management successfully reversed these complications.

The effect of pressure and shear on autologous fat grafting.

BACKGROUND: Fat grafting has become routine in plastic surgery because of low donor-site morbidity, a low complication rate, and fast recovery time. The optimal technique, however, has yet to be defined. Two critical variables are pressure and shear, both defined as force divided by area. In this study, the authors examined the effect of pressure and shear on human fat grafts in a nude mouse model. METHODS: For negative pressure, tumescent liposuction was performed on fresh panniculectomy specimens. Suction pressure was either -15 inHg or -25 inHg. Lipoaspirate was centrifuged at 1200 g and injected into the flanks of nude mice. For positive pressure, positive pressure was applied to lipoaspirate up to 6 atm for up to 3 minutes and then injected into nude mice. For shear stress, lipoaspirate was centrifuged at 1200 g for 3 minutes and then injected with a fast flow rate (3 to 5 cc/second) or slow flow rate (0.5 to 1 cc/second). After 4 weeks, the fat grafts were analyzed for weight and histology. RESULTS: For negative pressure, there were no differences in weight or histology with high versus low suction pressures. For positive pressure, application of positive pressures up to 6 atm for up to 3 minutes did not create a significant difference in graft weight or histology at 4 weeks. For shear stress, in vivo, a slow injection pressure yielded a 38 percent increase in weight (p < 0.001) compared with fast injection. Histology was similarly affected. CONCLUSIONS: Higher aspiration pressures up to -0.83 atm did not affect fat graft viability in vivo. Positive pressure up to 6 atm also did not affect fat graft viability. The degree of shear stress, which is a function of flow rate, did significantly affect fat graft viability. Fat grafts injected slowly with low shear stress significantly outperformed fat injected with high shear stress. These data suggest that shear stress is a more important variable regarding fat graft viability than pressure.

The Boston marathon bombings: the early plastic surgery experience of one Boston hospital.

BACKGROUND: On April 15, 2013, at approximately 2:49 p.m. EDT, two improvised explosive devices detonated near the finish line of the 117th Boston Marathon. Patients were transported from the scene to several trauma centers, including the authors' institution. METHODS: Plastic surgical assessment of patients began in the Emergency Department and then rapidly expanded as the scope of the incident became clear. Daily interdisciplinary meetings involving the acute care surgery, orthopedic surgery, plastic surgery, and nursing services were convened in order to coordinate operating room schedules and treatment plans. An interdisciplinary weekly clinic continued until all patient goals had been reached. RESULTS: Twenty-four patients were treated at Beth Israel Deaconess Medical Center within the first 24 hours of the Boston Marathon bombing. Seven were triaged directly to the operating room from the Emergency Department. The Division of Plastic Surgery was directly involved with the care of 11 patients, all of whom were treated surgically within 24 hours of the bombing. Patients were aged 23 to 50 years old. All 11 patients sustained lower extremity injuries with gross contamination. Four patients also sustained significant upper extremity trauma. Injuries included extremity amputations and fractures, soft-tissue loss, impaction of nails and other debris, burns, ocular injury, and ruptured tympanic membranes. CONCLUSIONS: Twenty-four patients received acute care at Beth Israel Deaconess Medical Center following the Boston Marathon bombing. Institution of dedicated interdisciplinary daily rounds, protected operating room block time, and joint follow-up clinic allowed for efficient early diagnosis and treatment of patients' injuries.

A novel approach to adipocyte analysis.

BACKGROUND: Fat grafting bench research is difficult because many traditional endpoints cannot be used reliably with adipocytes. Manual cell counting with trypan blue is a common method of measuring cell viability. There are, however, multiple known limitations, including human error, inability to analyze cell size, overestimation of adipocyte viability, and labor intensity. In this study, the authors demonstrate the effectiveness of an improved method of accurate adipocyte analysis using an automated cell counter. METHODS: Human lipoaspirate was obtained, centrifuged, and digested. Samples were analyzed using a hemocytometer and an automated cell counter with two viability dyes. Results were then optimized by novel methods of preparation using carboxymethyl cellulose and formalin. RESULTS: Manual trypan blue cell counts ranged from 2,750,000 to 19,200,000 live cells/ml. Automated cell counts significantly reduced variability (3,230,000 to 4,290,000 cells/ml). Counting cells between 40 and 150 µm, which is more specific to adipocytes, yielded 1,040,000 to 1,420,000 viable cells/ml. Using a second viability dye, CellTiter Blue, cell counts ranged between 993,000 and 1,340,000 live cells/ml. Adding carboxymethyl cellulose substantially decreased sampling variability by 80 percent, and the use of formalin prevented the decrease in cell counts over 4 hours from 432,000 to 7,000 cells/ml. CONCLUSIONS: This novel method utilizing automated cell counters can more accurately identify the viable adipocyte population without the limitations of traditional cell counting. In addition, the use of carboxymethyl cellulose and formalin in the preparation process can decrease variability and stabilize cell counts over time. This is an efficient, specific, and reliable method of adipocyte analysis.

Polymer therapy: a novel treatment to improve fat graft viability.

BACKGROUND: Autologous fat grafting is currently undergoing a renaissance. However, fat grafts are limited by unpredictable survival. Poloxamers can act as tissue surfactants. These nonionic surfactants have been shown to stabilize the membranes of damaged cells and to protect against injury and apoptosis in numerous models. This study was designed to investigate the ability of poloxamers to protect harvested adipocytes and to increase fat graft survival. METHODS: Lipoaspirate was obtained from surgical patients. Samples were washed in normal saline, centrifuged at 200 g, treated with various poloxamers or poloxamer components for 30 minutes, centrifuged at 200 g, and implanted into the flanks of nude mice in 1.0-cc, 1.0-g lobules. The grafts were explanted serially for 10 days and at 6 weeks. Endpoints were weight, apoptosis, cell viability, DNA content, and histology. RESULTS: Grafts treated with poloxamers P188, F108, and F127 demonstrated increased graft survival by weight. Fat grafts treated with poloxamers L64 and P188 demonstrated improvement in cell viability, and those treated with poloxamers L64, P188, and F38 demonstrated improved histology. P188-treated grafts demonstrated a 50 percent reduction in apoptosis compared with saline-treated controls (p < 0.05) and an overall 72 percent survival by weight at 6 weeks. P188 demonstrated statistically significant improvement by weight, DNA content, histology, and cell viability (89 percent versus 33 percent). CONCLUSIONS: The authors demonstrate that poloxamers, with membrane-sealing capability, can increase graft survival. Among these poloxamers, P188 demonstrated statistically significant improvement in apoptosis, graft survival by weight, cell viability, DNA content, and histology.