Grzegorz Kwiecien

Are Frozen Sections and MSIS Criteria Reliable at the Time of Reimplantation of Two-stage Revision Arthroplasty?

BackgroundFrozen section histology is widely used to aid in the diagnosis of periprosthetic joint infection at the second stage of revision arthroplasty, although there are limited data regarding its utility. Moreover, there is no definitive method to assess control of infection at the time of reimplantation. Because failure of a two-stage revision can have serious consequences, it is important to identify the cases that might fail and defer reimplantation if necessary. Thus, a reliable test providing information about the control of infection and risk of subsequent failure is necessary.Questions/purposes(1) At second-stage reimplantation surgery, what is the diagnostic accuracy of frozen sections as compared with the Musculoskeletal Infection Society (MSIS) as the gold standard? (2) What are the diagnostic accuracy parameters for the MSIS criteria and frozen sections in predicting failure of reimplantation? (3) Do positive MSIS criteria or frozen section at the time of reimplantation increase the risk of subsequent failure?MethodsA total of 97 patients undergoing the second stage of revision total hip arthroplasty or total knee arthroplasty in 2013 for a diagnosis of periprosthetic joint infection (PJI) were considered eligible for the study. Of these, 11 had incomplete MSIS criteria and seven lacked 1-year followup, leaving 79 patients (38 knees and 41 hips) available for analysis. At the time of reimplantation, frozen section results were compared with modified MSIS criteria as the gold standard in detecting infection. Subsequently, success or failure of reimplantation was defined by (1) control of infection, as characterized by a healed wound without fistula, drainage, or pain; (2) no subsequent surgical intervention for infection after reimplantation surgery; and (3) no occurrence of PJI-related mortality; and diagnostic parameters in predicting treatment failure were calculated for both the modified MSIS criteria and frozen sections.ResultsAt the time of second-stage reimplantation surgery, frozen section is useful in ruling in infection, where the specificity is 94% (95% confidence interval [CI], 89%–99%); however, there is less utility in ruling out infection, because sensitivity is only 50% (CI, 13%–88%). Both the MSIS criteria and frozen sections have high specificity for ruling in failure of reimplantation (MSIS criteria specificity: 96% [CI, 91%–100%]; frozen section: 95% [CI, 88%–100%]), but screening capabilities are limited (MSIS sensitivity: 26% [CI, 9%–44%]; frozen section: 22% [CI, 9%–29%]). Positive MSIS criteria at the time of reimplantation were a risk factor for subsequent failure (hazard ratio [HR], 5.22 [1.64–16.62], p = 0.005), whereas positive frozen section was not (HR, 1.16 [0.15–8.86], p = 0.883).ConclusionsOn the basis of our results, both frozen section and MSIS are recommended at the time of the second stage of revision arthroplasty. Both frozen section and modified MSIS criteria had limited screening capabilities to identify failure, although both demonstrated high specificity. MSIS criteria should be evaluated at the second stage of revision arthroplasty because performing reimplantation in a joint that is positive for infection significantly increases the risk for subsequent failure.Level of EvidenceLevel III, diagnostic study.

A new vascularized cervical lymph node transplantation model: an anatomic study in rats.

IntroductionVascularized lymph node transfer is of high interest for the treatment of lymphedema. Currently, there are few experimental small animal models of vascularized lymph node transplantation. In this article, our aim was to describe a new vascularized cervical lymph node transplantation model in rats. Materials and MethodsTen male Sprague-Dawley rats weighing 200 to 250 g were used in this study. The anatomic features of the neck lymph nodes in rats were explored. Anatomic neck dissections were performed, and lymph node flaps were harvested. The common carotid artery and the jugular vein were used as the vascular pedicles of the lymph node flap. Methylene blue dye was injected into the arterial pedicle. Lymph nodes were identified, and their structure was confirmed by histological evaluation. Laser-assisted indocyanine green angiography was used to confirm perfusion of the lymph node flap. ResultsAn adequate perfusion was observed in the lymph node flap. The dye disseminated evenly within the lymph nodes, indicating that the flap had a well-established vascular network and an adequate blood supply. Macroscopically, perfusion of 5 to 6 lymph nodes was observed. Histological examination of tissue samples confirmed well-defined lymph nodes. After indocyanine green administration, fluorescence was observed throughout the lymph node flap and within the venous pedicle of the flap. ConclusionsTo the best of our knowledge, this is the first report describing vascularized lymph node flap in the head and neck region of a rat. Our lymph node flap preparation technique confirmed the presence of 5 to 6 lymph nodes within the flap. The presented vascularized lymph node flap can be applied to transplantation studies, lymphedema studies, and to studies on immunological mechanism of tolerance and rejection.

Microsurgical Anatomy of the Terminal Hypoglossal Nerve Relevant for Neurostimulation in Obstructive Sleep Apnea.

Neurostimulation of the hypoglossal nerve has shown promising results in the treatment of obstructive sleep apnea. This anatomic study describes the detailed topography of the hypoglossal nerves motor points as a premise for super‐selective neurostimulation in order to optimize results and minimize the risk of complications related to main nerve trunk manipulation.

Long-term outcomes of total knee arthroplasty following soft-tissue defect reconstruction with muscle and fasciocutaneous flaps

Background: Insufficient soft-tissue coverage following total knee arthroplasty jeopardizes prosthesis retention and may lead to significant complications. The aim of this study was to evaluate the natural history of total knee arthroplasty following flap reconstruction of soft-tissue defects. Methods: A retrospective review of patients treated with flaps after failed total knee arthroplasty between 1998 and 2013 was conducted. Patients with preexisting soft-tissue defects who required reactive flap reconstruction were included in group 1. Patients with no preexisting soft-tissue defects, but with extensive débridement during revision total knee arthroplasty requiring immediate proactive flap coverage, were included in group 2. Results: Fifty-eight patients in group 1 were treated with 86 flaps, and 15 patients in group 2 were treated with 17 flaps. Mean length of follow-up was 67.0 and 54.7 months, respectively (p = 0.21). Flap-related complications and number of subsequent flap revisions were comparable in both groups. Patients in group 1 had a higher rate of implant reinfection (58 percent versus 27 percent; p < 0.05), amputations (25 percent versus 0 percent; p < 0.05), and subsequent prosthesis revisions (2.2 versus 0.9; p < 0.05). Functional joint was preserved in 54 percent and 80 percent of cases, respectively. Mean gain in range of motion and quality of life were significantly better in group 2 (p < 0.05). Conclusions: Early proactive soft-tissue coverage of total-knee arthroplasty is critical to long-term success. In cases where reactive treatment is required, significantly worse outcomes and a high rate of complications should be expected. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Repair of the peripheral nerve gap with epineural sheath conduit to prevent muscle denervation atrophy in the diabetic rat model

UNLABELLED Muscle denervation atrophy is a result of lower motor neuron injury, thus an early restitution of muscle stimulation is essential in prevention of atrophic changes. THE AIM OF THE STUDY To evaluate the new application of naturally occurring epineural sheath conduit in repair of the peripheral nerve gap to prevent development of muscle denervation atrophy. MATERIAL AND METHODS We used the model of 20 mm sciatic nerve gap, resulting in denervation atrophy of the gastrocnemius muscle in the diabetic rats (DM type 2, n=42, Zucker Diabetic Fatty strain). We applied the epineural sheath conduit created from the autologous sciatic nerve for gap repair. Muscle atrophy was assessed with the Gastrocnemius Muscle Index (GMI) and microscopic muscle morphometry (mean fiber area) at 6 and 12 postoperative week. Muscle regeneration in the experimental group was compared to the gold-standard technique of autologous nerve grafting for the repair of created nerve gap. RESULTS The GMI evaluation revealed comparable muscle mass restoration in groups with nerve repair using both epineural sheath and standard autologous nerve grafting (reaching 28 and 35% of contralateral muscle mass at 12 postoperative week, respectively, p=0.1), and significantly better restoration when compared to the negative control group (no repair, 20%, p<0.01). Micromorphometry confirmed significantly larger area of the regenerated muscle fibers in groups with both nerve grafting and epineural sheath conduit repair (reaching for both ca. 42% of the non-operated side), when compared to severe atrophic outcome when no nerve repair was performed (14% of the control fiber area, p<0.0001). The effectiveness of epineural conduit technique in muscle mass restoration was observed between 6 and 12 weeks after nerve repair--when gastrocnemius muscle mass increased by 12%. CONCLUSIONS Peripheral nerve gap repair with naturally occurring epineural sheath conduit is effective in prevention of muscle denervation atrophy. This method is applicable in diabetic model conditions, showing results of regeneration which are comparable to the autologous nerve graft repair.

Applying to Integrated Plastic Surgery Residency Programs: Trends in the Past 5 Years of the Match.

Background: The average integrated plastic surgery applicant spends over

Vascularized axillary lymph node transfer: A novel model in the rat.

6000 for interviews. The average program director reviews over 200 applications per cycle. It is important to make the application process efficient and cost effective for both applicants and programs. The authors analyzed recent trends and the literature in an attempt to increase the likelihood that applicants match, suggest means of reducing applicants’ costs, and improve the process. Methods: A cross-sectional study of the National Residency Matching Program Charting Outcomes and results and data for the years 2009 to 2014 was performed. Applicant profile elements were examined for differences between matched/unmatched U.S. senior medical students. In addition, a literature review was performed. Results: The number of integrated plastic surgery positions rose from 69 in 2010 to 130 in 2014. Both matched and unmatched U.S. senior medical students have higher Step 2 scores, research and volunteer experiences, than 5 years ago. The likelihood of matching into an integrated plastic surgery residency has increased (2009, 52 percent; 2011, 44 percent; and 2014, 71 percent). Successful match rates were associated with Alpha Omega Alpha status and graduating from a top-40 ranked medical school (p < 0.05). Applicants with a lower number of ranked programs had increased match rates in 2014 than in previous years. Literature review revealed that program directors also value strong recommendation letters, publications, persistent work ethic (“grit”), away rotations, and an accurate curriculum vitae. Conclusions: Within the setting of increased applicant competitiveness, the authors recommend maximizing subjective qualities in order to differentiate themselves from a highly eligible applicant pool. In addition, applicants should diversify the types of programs at which they interview to maximize their chances of matching.

A Subglandular Breast Cerebrospinal Fluid Pseudocyst Following Postsurgical Shunt Migration.

Vascularized lymph node transfer (VLNT) is a promising microvascular free flap technique for the surgical treatment of lymphedema. To date, few experimental animal models for VLNT have been described and the viability of lymph nodes after the transfer tested. We aimed to evaluate the feasibility of axillary VLNT in the rat. Lymph node containing flaps were harvested from the axillary region in 10 Lewis rats based on the axillary vessels. Flaps were transferred to the ipsilateral groin and end‐to‐side microanastomosis was performed to the femoral vessels using 10‐0 sutures. Indocyanine green (ICG) angiography was used to confirm flap perfusion. On postoperative day 7, flaps were elevated to assess their structure and vessel patency. Hematoxylin and eosin staining was used to confirm the presence and survival of lymph nodes. All animals tolerated the procedure well. Immediate post‐procedure ICG angiography confirmed flap perfusion. No signs of ischemia or necrosis were observed in donor extremities. At postoperative day 7, all flaps remained viable with patent vascular pedicles. Gross examination and histology confirmed the presence of 3.6 ± 0.5 lymph nodes in each flap without any signs of necrosis. This study showed that the transfer of axillary lymph nodes based on the axillary vessels is feasible. The flap can be used without the need for donor animals and it contains a consistent number of lymph nodes. This reliable VLNT can be further utilized in studies involving lymphedema, transplantation, and induction of immunologic tolerance.

Sheep hemifacial and auricular transplantation models: an anatomic study.

Summary: Cerebrospinal fluid (CSF) drainage catheters have been associated with numerous complications in various anatomic locations, because of migration, infection, and obstruction. However, breast-related CSF shunt complications tend to occur infrequently or have seldom been reported in the empirical literature. Therefore, a case is presented detailing a breast pseudocyst caused by migration and subsequent coiling of a ventriculoperitoneal shunt in the right breast pocket. To the best of the authors’ knowledge, this is the first case that has been reported in the peer-reviewed literature of a pseudocyst resulting from a CSF drainage catheter coiling around the breast implant post pancreaticoduodenectomy. Moreover, this case highlights the importance of cross-disciplinary procedural awareness, particularly in regards to breast, ventriculoperitoneal shunt, and pancreatic procedures.

Quantity of Lymph Nodes in the Vascularized Lymph Node Transfer Influences Its Lymphaticovenous Drainage

IntroductionCurrently, only a few large animal models, including swine, dog, and nonhuman primate, are described for composite face transplantation studies and the literature lacks reports on the large animal model of composite auricular transplantation. Large animal models offer better understanding of the immunological mechanisms and major histocompatibility complex characterization and, for this reason, are preferred to the small animal models for the assessment of new immunosuppressive tolerance induction protocols. Thus, the aim of this study was to demonstrate feasibility of dissection and exploration of vascular territories of the hemifacial and auricle transplantation models in the sheep cadavers. Materials and MethodsTen cadaver sheep heads were studied. The vascular territories of the composite hemifacial flap and composite auricle flap were defined by anatomical dissection. Methylene blue staining and laser-assisted indocyanine green angiography using SPY Elite System were used for vascular territories assessment. ResultsThe dissection of cadaver sheep heads confirmed that the hemifacial flap and auricle flap can be raised on the same pedicle consisting of the common carotid artery and jugular vein. An adequate vascular network was observed in the flaps after injection of methylene blue dye via the arterial pedicle. Laser-assisted indocyanine green angiography identified vascular territories of the hemifacial and auricular vascular network. ConclusionsWe described a new hemifacial and an auricular transplantation models in the sheep cadavers and have confirmed presence of the adequate vascular network as demonstrated by the laser-assisted angiography. This study introduces 2 new large animal models into the armamentarium of vascular composite allotransplantation.