John C. Kirkham

The effect of pressure and shear on autologous fat grafting.

1. Aygit AC, Basaran K, Mercan ES. Transaxillary totally subfascial breast augmentation with anatomical breast implants: Review of 27 cases. Plast Reconstr Surg. 2013;131:1149–1156. 2. Hwang K, Kim DJ. Anatomy of pectoral fascia in relation to subfascial mammary augmentation. Ann Plast Surg. 2005;55:576–579. 3. Jinde L, Xiaoping C, Wanquan Z, Xia G, Ligang X. Can the pectoral fascia integrity be preserved during subfascial breast augmentation through the axillary approach? Aesthetic Plast Surg. 2010;34:29–32. 4. Salgarello M, Visconti G, Barone-Adesi L, et al. Inverted-T skin-reducing mastectomy with immediate implant reconstruction using the submuscular-subfascial pocket. Plast Reconstr Surg. 2012;130:31–41. 5. Salgarello M, Visconti G, Barone-Adesi L. One-stage immediate breast reconstruction with implants in conservative mastectomies. In: Salgarello M, ed. Breast Reconstruction: Current Techniques. Rijeka, Croatia: In-Tech; 2012:49–82. Available at: www.intechopen.com.

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.

PurposeAutologous 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 TechniquesControlled 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. ResultsAt 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. ConclusionsIn 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.

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.

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.

Leiomyoma and leiomyosarcoma arising from the round ligament of the uterus.

2 43-year-old woman presented with an asymptomatic, nlarging right groin mass she had first noticed 6 months arlier. On examination, she had a soft, mobile, nontender ass in the right inguinal region. MRI demonstrated a eterogeneous 9-cm SC tumor (A), and CT-guided biopsy howed leiomyoma. At operation, a well-encapsulated tuor was found originating from the right round ligament f the uterus and this mass was completely resected. Miroscopic analysis revealed elongated cells, cigar-shaped uclei, and low mitotic activity, consistent with benign ellular leiomyoma (B). A 47-year-old woman presented with a left groin mass hich had enlarged over 4 months with no symptoms. RI revealed a 5-cm mass in the left inguinal region (C), nd CT-guided biopsy showed a grade II/III leiomyosaroma comprised of intersecting fascicles with pleomorphic uclei (D). She received 50 Gy of preoperative radiation. t operation, the mass, arising from the round ligament of he uterus, was resected along with the round ligament and urrounding abdominal wall, and the abdominal wall was econstructed with mesh. Pathology confirmed leiomyoarcoma with negative margins. One year after operation, he remains well, with no clinical or radiographic evidence A

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 &mgr;m, 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.

Fat Graft Survival: Physics Matters.

To the Editor: We appreciate the comments made by Dr Shipvok and colleagues with regard to our recent article ‘‘Acute nasal reconstruction with forehead f lap after dog bite.’’ We also thank them for bringing to our attention other citations of mammalian bite injuries to the head and neck, and we congratulate them on their recent, large review of their experience in pediatric bite injuries. As our colleagues note, most of bite injuries to the head and neck can be immediately and safely closed primarily. Because of the robust vascularity of the face, infection is not frequently encountered. The indications for flap closure in these particular injuriesVand specifically of forehead flap closure of nasal defectsVreflect more general algorithms for nasal reconstruction. These are defined by the size and type of tissue loss, as they have explained in their letter. We agreewith them that immediate flap reconstruction, when indicated, offers the advantages of decreased fibrosis and decreased psychological impact of the injury. Because bite injuries to the nose requiring forehead flap reconstruction are relatively and fortunately rare, our understanding and treatment methods are slow to change and mature. As we noted in our conclusion, immediate cartilage grafting for structural support would likely have decreased the resultant nasal stenosis noted in our cases. Such cartilage grafting would have required a more intensive operation, as the nasal lining would require its own blood supply, possibly with mucoperichondrial f laps or extended forehead f laps that wrap a cartilage graft between a thinned flap folded on itself. However, we are hesitant to explicitly dissuade other colleagues from attempting immediate cartilage grafting, as it would theoretically provide a more anatomical, trilaminar reconstruction, and it may lead to better, long-term results. We hope to encounter reports of these reconstructions in the future. Again, we thank our colleagues for their interest in our article and for their contributions to understanding the management of these challenging cases.

The Effect of Pressure and Shear on Fat Grafting

Methods: Negative Pressure: Liposuction was performed in the laboratory on panniculectomy specimens. Suction pressure was either -15 inches Hg (-0.5 atmosphere) or -25 inches Hg (-0.83 atmosphere). Lipoaspirate was centrifuged at 1200G and injected into the flanks of nude mice. Positive Pressure: Lipoaspirate was obtained and positive pressure was applied up to 6 atmospheres for up to 3 minutes and then injected into nude mice. Shear Stress: Lipoaspirate was centrifuged at 1200G for 3 minutes and then injected at two different speeds: fast flow rate (3-5 cc/sec) versus slow flow rate (0.5-1 cc/sec). After 4 weeks, the fat grafts were analyzed for weight and histology.