Karem C. Harth

Analysis of the rising incidence of thyroid cancer using the Surveillance, Epidemiology and End Results national cancer data registry

BACKGROUND The incidence of thyroid cancer has more than doubled in recent decades. Debate continues on whether the increasing incidence is a result of an increased detection of small neoplasms or other factors. METHODS Using the Surveillance, Epidemiology and End Results database, we examined the overall incidence of thyroid cancer with variations based on tumor pathology, size, and stage, as well as the current surgical and adjuvant therapy of thyroid carcinoma. RESULTS Thyroid cancer incidence increased 2.6-fold from 1973 to 2006. This change can be attributed primarily to an increase in papillary thyroid carcinoma, which increased 3.2-fold (P < .0001). The increase in papillary thyroid carcinoma also was examined based on tumor size. Tumors ≤ 1 cm increased the most at a total of 441% between 1983 and 2006 or by 19.2% per year, the incidence of papillary thyroid carcinoma also increased at 12.3%/year in 1.1-2-cm tumors, 10.3%/year in 2.1-5-cm tumors, and 12.0%/year for > 5-cm tumors (all P < .0001 by Cochran-Armitage trend test). We also demonstrated a positive correlation between papillary thyroid carcinoma tumor size and stage of disease (Spearman, r = 0.285, P < .0001). Operative treatment for thyroid cancer also has shifted with total thyroidectomy replacing partial thyroidectomy as the most common surgical procedure. CONCLUSION Contrary to other studies, our data indicate that the increasing incidence of thyroid cancer cannot be accounted for fully by an increased detection of small neoplasms. Other possible explanations for the increase in clinically significant (> 1 cm) well-differentiated thyroid carcinomas should be explored.

Endoscopic versus open component separation in complex abdominal wall reconstruction

BACKGROUND Open component separation has a high wound complication rate. Newer endoscopic approaches are described with no comparative trials. METHODS A retrospective review (2005-2009) of patients undergoing open or endoscopic component separation was performed. RESULTS Forty-four cases were identified (22 endoscopic; 22 open). All perioperative variables were the same except age (65 open vs 55 endoscopic; P<.05). Hospital length of stay was 11 days in the open group versus 8 days in the endoscopic group (P=.09). Wound complications were 52% in the open group versus 27% in the endoscopic group (P=.09). Wound-related interventions occurred in 45% of the open group and 33% of the endoscopic group. Hernia recurrences rates were similar (open, 32%; endoscopic, 27%; P=.99). CONCLUSIONS Open and endoscopic components separation have similar rates of recurrence. The endoscopic group had shorter lengths of stay and less major wound complications. The endoscopic approach may be the ideal technique for complex abdominal wall reconstruction.

Major Complications Associated With Xenograft Biologic Mesh Implantation in Abdominal Wall Reconstruction

Background. There is limited research for xenograft biologic mesh performance in the setting of infection despite widespread use and significant associated costs. Design. The authors retrospectively reviewed an FDA database for reported xenograft adverse events (AEs). All meshes were used in the setting of abdominal wall reconstruction from 1997 to 2008. Results. The authors identified 150 AEs. Permacol and Collamend comprised 75% (n = 112) of reported cases. Main AEs included acute mechanical failure (42%; n = 63), mesh disintegration (32%; n = 48), and poor mesh integration (13%; n = 20); 80% of cases were described as infected, and nearly 90% of AEs required reoperation. Conclusions . Major complications are reported to the FDA for xenograft biologic meshes. Cross-linked meshes had the most AE reports to the FDA. The intrinsic properties of meshes and how they relate to infection-related outcomes are poorly understood. The findings from this FDA database review point toward a need to carefully evaluate these products.

Optimum repair for massive ventral hernias in the morbidly obese patient—is panniculectomy helpful?

BACKGROUND The appropriate surgical management of morbidly obese patients with symptomatic hernias is not well defined. The authors evaluated the role of simultaneous panniculectomy in complex abdominal wall reconstruction. METHODS A retrospective study (2007-2010) was conducted of morbidly obese (body mass index > 40 kg/m(2)) patients undergoing open complex abdominal wall reconstruction. RESULTS Thirty patients were identified. Twenty underwent simultaneous panniculectomy. The median pannus weight was 5.2 kg. Greater all-cause postoperative complications and wound-related morbidity occurred in the panniculectomy group (P < .05). Performing a panniculectomy increased the risk for a wound complication by 5-fold (P = .04). Following 7-month to 9-month follow-up, both groups had a recurrence rate of 10%. CONCLUSION Simultaneous panniculectomy in the setting of complex abdominal wall reconstruction is feasible but associated with significant postoperative morbidity. Its potential for benefit in reducing long-term hernia recurrence remains unclear.

Novel in Vitro Model for Assessing Susceptibility of Synthetic Hernia Repair Meshes to Staphylococcus aureus Infection Using Green Fluorescent Protein-Labeled Bacteria and Modern Imaging Techniques

BACKGROUND Mesh infection complicating hernia repair is a major cause of patient morbidity and results in substantial healthcare expenditures. The various constructs of prosthetic mesh may alter the ability of bacteria to attach and form a biofilm. Few data exist evaluating biofilm formation. Using the Maestro in-Vivo Imaging System (CRi, Inc., Woburn, MA) to detect green fluorescent protein (GFP)-expressing Staphylococcus aureus, we studied the ability of synthetic mesh to withstand bacterial biofilm formation in an in vitro model. METHODS We included four meshes: Polypropylene (PP), polypropylene/expanded PTFE (PX), compressed PTFE (cPTFE), and polyester/polyethylene glycol and collagen hydrogel (PE). Five samples of each mesh were exposed to GFP-expressing S. aureus for 18 h at 37°C. Next, green fluorescence was measured using the Maestro Imaging System, with the results expressed in relative fluorescence units (RFU), subtracting the fluorescence of uninfected mesh (control). Each mesh subsequently underwent sonication and quantitative culture of the released bacteria, with the results expressed in colony-forming units (CFU). Analysis of variance was performed to compare the mean values for the different meshes. RESULTS There was a statistically significant difference in bacterial fluorescence for the four meshes: PE (49.9 ± 25.5 [standard deviation] RFU), PX (30.8 ± 9.4 RFU), cPTFE (10.1 ± 4.0 RFU), and PP (5.8 ± 7.5 RFU)(p = 0.001). Bacterial counts also were significantly different: PE (2.2 × 10(8) CFU), PX (8.6 × 10(7) CFU), cPTFE (3.7 × 10(7) CFU), and PP (9.1 × 10(7) CFU)(p < 0.001). CONCLUSION Using novel imaging technology, this study documented significantly different amounts of S. aureus biofilm formation and proliferation on different mesh constructs, with good agreement between imaging and culture results. A multifilament woven mesh (PE) had the highest degree of biofilm formation. These findings are being evaluated in a clinical infection model.

Effect of surgical wound classification on biologic graft performance in complex hernia repair: an experimental study.

BACKGROUND Despite relatively sparse data regarding their outcomes in the setting of infection, biologic grafts have gained rapid acceptance by the surgical community for complex hernia repair. These materials are heterogeneous in their procurement and processing techniques, which may ultimately have an impact in their ability to withstand infection. The objective of this study is to evaluate the impact of varying levels of contamination on biologic graft performance in a chronic ventral hernia animal model. METHODS Four commonly applied biologic grafts were used in the repair of a chronic ventral hernia rat model (n = 218). Each material was repaired in the setting of 1 of 4 surgical wound classifications (clean, clean contaminated, contaminated, dirty infected) with Staphylococcus aureus as our inoculum agent. After a 30-day survival, repairs underwent quantitative cultures, histological, and biomechanical testing. RESULTS Marked differences were observed in biologic graft bacterial burden, biomechanical and histological responses at 30 days. Persistent bacterial burden varied among the biologic grafts and increased with increasing wound contamination (P < .05). Delays in wound healing were observed in the contaminated and dirty infected setting (P < .05). Increasing infection weakened the biomechanical strength of repairs (P < .05). CONCLUSION The degree of bacterial contamination at the time of repair affected the rates of bacterial clearance, wound-healing ability, and subsequent repair strength. Material source and processing techniques might alter graft durability, biocompatibility, and ability to clear bacteria in a contaminated field. Clinical trials are warranted in contaminated settings.

Stitch versus scar--evaluation of laparoscopic pediatric inguinal hernia repair: a pilot study in a rabbit model.

BACKGROUND Many have questioned whether the laparoscopic, percutaneous hernia repair technique is as durable as an open repair in which the sac is divided and ligated. We set out to assess if the suture alone causes enough injury and scar over time to obliterate the internal ring. MATERIALS AND METHODS In total, 28 male rabbits with congenital patent processus vaginalis underwent laparoscopic repair with the subcutaneous endoscopically assisted ligation technique. For Group 1 the repairs were evaluated laparoscopically at predetermined time points before and after removal of the ligating suture. Group 2 assessed the effect of sharp peritoneal trauma at the time of repair and was evaluated at 2 and 4 weeks. RESULTS When durability of repair with suture alone was evaluated, all repairs failed after insufflation to 35 mm Hg after suture removal out to a time point of 12 weeks. In the peritoneal trauma group, at the 2- and 4-week survival time point, 87.5% and 100%, respectively, of repairs remained intact after removal of suture. In contrast, only 25% and 12.5%, respectively, of defects remained closed in the animals repaired with suture ligation alone. CONCLUSIONS The laparoscopic, percutaneous hernia repair may rely heavily on the suture itself to prevent recurrence. In the event of suture failure, this could lead to an increasingly high recurrence rate. The addition of minor peritoneum trauma may induce sufficient scarring to provide a more durable repair.

Predicting severe postoperative respiratory complications following abdominal wall reconstruction.

Background: Patients undergoing abdominal wall reconstruction are at risk of developing major postoperative respiratory complications. The authors attempted to identify factors predictive of respiratory complications following abdominal wall reconstruction. Methods: All patients who underwent complex abdominal wall reconstruction over a 2-year period were reviewed. The primary endpoint studied was severe respiratory complication, defined as respiratory insufficiency requiring intubation or transfer to a higher level of care. Results: Sixty patients underwent complex abdominal wall reconstruction during the study period. The incidence of respiratory complications was 20 percent. Factors predictive of postoperative respiratory complication included age (p = 0.05), American Society of Anesthesiologists score (p = 0.04), and hernia defect size (p = 0.01). In addition, patients who developed respiratory complications were more likely to have had a greater change in plateau pressure (5.8 versus 2.3 cmH2O; p = 0.01). The greater the change in plateau pressure, the greater the risk of developing a respiratory complication: for a change in plateau pressure greater than or equal to 6 cmH2O, the odds ratio was 8.67; for a change in plateau pressure greater than or equal to 9 cmH2O, the odds ratio was 11.5. Conclusions: Respiratory complications following abdominal wall reconstruction can be serious and are associated with prolonged hospitalizations. Patients with an increase in their plateau pressure of greater than 6 cmH2O are at an increased risk of severe postoperative respiratory complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

Human Peritoneal Membrane Controls Adhesion Formation and Host Tissue Response Following Intra-Abdominal Placement in a Porcine Model

BACKGROUND Even with the advent of bioresorbable barriers, complications due to visceral adhesions following surgery continue to occur. The use of a homologous adhesive barrier such as human peritoneal membrane (HPM) could prevent adhesions formation and enhance wound healing. This study evaluates HPM as an effective adhesive barrier in a porcine model simulating a ventral hernia procedure. MATERIALS AND METHODS Through a midline laparotomy, meshes (10 cmx10 cm) were sewn onto the intact peritoneum of a pig, on each side of a midline incision in superior and inferior positions (4 randomized meshes/pig, n=9 pigs). The pigs were survived for 90 d. The meshes used were: HPM, compressed polytetrafluoro-ethylene (cPTFE), cPTFE+HPM, and polyester-collagen composite (PX). Exploratory laparoscopy was performed at 30 and 90 d to evaluate the extent of visceral adhesions. At necropsy, the extent and tenacity of visceral adhesions as well as material-abdominal wall integration were evaluated. Finally, host tissue response was assessed through scoring of inflammation, foreign body reaction, and mesothelialization. RESULTS HPM and PX led to the least extent and tenacity of visceral adhesions compared to cPTFE and cPTFE+HPM, but integrated less strongly within the adjacent abdominal wall. PX displayed the most robust foreign body reaction among all prosthetic materials, while HPM scored similarly to the native peritoneum. The extent of mesothelialization was similar throughout the materials tested. CONCLUSIONS The HPM barrier which promotes long-term peritoneal remodeling could diminish postsurgical intraperitoneal adhesions following hernia repair.