Vacuum-assisted closure: state of basic research and physiologic foundation

A tremendous amount of research has been conducted in recent years investigating the mechanisms of action by which the application of subatmospheric pressure to wounds increases the rate of healing. Similarly, numerous studies have also been conducted examining the physiologic response of wounds to the applied subatmospheric pressure. However, many more need to be conducted. A series of basic studies examining the use of subatmospheric pressure to treat wounds is presented, including the original studies upon which the vacuum-assisted closure device was based (on blood flow, granulation tissue formation, bacterial clearance, and survival of random-pattern pedicle flaps). Subsequent studies analyzing removed fluids, envenomation/extravasation, burns, grafts, and in vitro tissue culture studies are also reviewed. Two broad mechanisms of action are proposed: removal of fluid and mechanical deformation. Fluid removal both decreases edema--thus decreasing interstitial pressure and shortening distances of diffusion--and removes soluble factors that may affect the healing process (both positively and negatively). The relationship of mechanical deformation to increased growth is well known to plastic surgeons, as it is the basis of tissue expansion. While much has been done, a great deal more needs to be done to elucidate the mechanisms of action responsible for the dramatic response seen clinically.

Local Application of Probiotic Bacteria Prophylaxes against Sepsis and Death Resulting from Burn Wound Infection

Objective

To determine if local prophylactic application of probiotic bacteria to burn wounds will prevent death in a mouse model of burn wound sepsis.

Background

Infection remains the most common complication after burn injury and can result in sepsis and death, despite the use of topical and systemic antibiotics. Pseudomonas aeruginosa is a frequently implicated pathogen. Local application of probiotics directly to burn wounds is an attractive novel intervention that avoids the pitfalls of standard antibiotic therapies.

Methods

A burn-sepsis model was established using a sub-eschar injection of bioluminescent P. aeruginosa; infection was tracked using a charge-coupled camera. Full-thickness burn injuries were placed on the dorsums of adult mice; the injured sites were then treated with vehicle (burn wound control), probiotics (Lactobacillus plantarum only), pathogenic bacteria (Pseudomonas aeruginosa only), or probiotics plus pathogen (Lactobacillus plus Pseudomonas). Animals were monitored until death/moribundity or for one week, then sacrificed. Harvested tissues were subjected to imaging and molecular assays.

Results

Control and probiotic-only animals showed no mortality (100% survival) at one week. Pseudomonas-only animals showed > 90% mortality within 40 hours of infection. In contrast, animals treated with probiotics plus Pseudomonas showed less than 10% mortality. Use of bioluminescent Pseudomonas bacteria demonstrated that probiotic therapy inhibited septicemic accumulation of the pathogen in remote organs. In addition, probiotic therapy successfully suppressed the infection-dependent induction of TNF-α and interleukins 6 and 10 in the liver.

Conclusions

Local probiotic therapy shows great potential as a valuable adjunct in the management of complicated burn injury.

Stereological quantification of GAD-67-immunoreactive neurons and boutons in the hippocampus of middle-aged and old Fischer 344 x Brown Norway rats

The aging process in rodents is associated with learning and memory impairments that are correlated with changes in multiple neurotransmitter systems in the hippocampus. For example, the gamma-aminobutyric acid (GABA)ergic system is compromised in old compared with young rats (Shetty and Turner [1998] J. Comp. Neurol. 394:252-269; Vela et al. [2003] J. Neurochem. 85:368-377; Potier et al. [1992] Neuroscience 48:793-806; Potier et al. [1994] Brain Res. 661:181-188). The present study investigated the important issue of whether there is a decline of the GABAergic inhibitory system between middle and old age. Five middle-aged (15-17 months) and five old (25-29 months) Fischer 344 x Brown Norway male rats were perfused, and coronal sections through the dorsal hippocampus were immunoreacted with antibodies either to NeuN, a neuronal marker, or to the 67-kDa isoform of glutamic acid decarboxylase (GAD), the rate-limiting enzyme for GABA synthesis. Using the optical dissector technique, NeuN-immunoreactive (IR) cells, GAD-IR cells, and GAD-IR boutons were quantified stereologically in the dentate gyrus, CA3, and CA1. The resulting GAD-IR cell and GAD-IR bouton densities then were normalized to NeuN-IR cell density to exclude the possible confound of tissue shrinkage. The results revealed a significant decline in GAD-IR cells between middle and old age in CA1 but not in dentate gyrus or CA3. Interestingly, GAD-IR boutons did not show a decline in CA1, CA3, or dentate gyrus between middle and old age. It is possible that loss of CA1 inhibitory interneurons in the dorsal hippocampus contributes to the learning and memory impairments reported in old rats.

Maintenance of inhibitory interneurons and boutons in sensorimotor cortex between middle and old age in Fischer 344 X Brown Norway rats

Ultrastructurally identified inhibitory synapses in layer II of rat sensorimotor cortex decline between middle and old age [Poe, B.H., Linville, C., Brunso-Bechtold, J., 2001. Age-related decline of presumptive inhibitory synapses in the sensorimotor cortex as revealed by the physical disector. J. Comp. Neurol. 439, 65-72]. The current study investigated whether a loss or shrinkage of gamma-aminobutyric acid (GABA)ergic interneurons contribute to that decline. Coronal sections from middle-aged (15-17 months) and old (25-29 months) Fischer 344 X Brown Norway male rats were immunoreacted with antibodies to the GABA synthesizing enzyme glutamic acid decarboxylase (GAD); the calcium-binding protein parvalbumin (PV), or the neuronal marker NeuN. The number of GAD-immunoreactive (IR), PV-IR, and NeuN-IR cells were determined stereologically using the optical disector technique and the cross-sectional areas of GAD-IR cells were measured in layers II/III, IV, V and VI of sensorimotor cortex. Neither the number of GAD-IR or NeuN-IR cells, nor the size of GAD-IR cells, declined significantly between middle and old age. A modest decline in the PV-IR subset of inhibitory interneurons was observed, predominantly due to changes in layers V and VI. Stereological analysis of layer II/III GAD-IR boutons revealed a stability of immunocytochemically identified inhibitory terminals. Taken together, these results indicate a general maintenance of overall GABAergic neurons in sensorimotor cortex between middle and old age and the loss of ultrastructurally identified inhibitory synapses may be due to the decline of a subset of GABAergic terminals.

Complications of Cosmetic Surgery Tourism: Case Series and Cost Analysis

BACKGROUND

Cosmetic surgery tourism is increasing exponentially. Patients seek cosmetic procedures within the United States and abroad, lured by lower cost procedures, shorter waiting lists, and affordable airfare and hotel accommodations. Unfortunately, operations are often performed by non-board-certified plastic surgeons, sometimes not even by plastic surgeons. Preoperative counseling, frequently limited to a video-chat with an office secretary, provides inadequate discussion regarding potential complications. Postoperative care is careless and rarely involves the operating surgeon. Complications are frequent, with management falling into the hands of plastic surgeons unfamiliar with the patient's care. Furthermore, the physician, rather than the patient or hospital, faces the largest cost burden.

OBJECTIVES

The authors sought to explore their institution's experience treating complications of cosmetic tourism and investigate associated costs.

METHODS

The retrospective review of 16 patients treated for complications related to cosmetic surgery tourism plus cost analysis revealed a substantial discrepancy between money saved by undergoing surgery abroad and massive costs accrued to treat surgical complications.

RESULTS

The most common complication was infection, often requiring surgery or IV antibiotics on discharge. Mean cost per patient was $26,657.19, ranging from $392 (single outpatient visit) to $154,700.79 (prolonged admission and surgery). Overall, the hospital retained 63% of billed charges, while physicians retained only 9%. The greatest amount paid by any single patient was $2635.00 by a patient with private insurance.

CONCLUSIONS

Cosmetic tourism has severe medical repercussions for patients and complications that burden hospitals, physicians, and the US medical system. Physicians treating the complications suffer the greatest financial loss.

LEVEL OF EVIDENCE: 4

Dynamic Spring Mediated Cranioplasty in an Experimental Model With Resorbable Foot Plates

Craniofacial surgery continues to be progressive in its approach to maximize function and aesthetic appearance while minimizing risks and complications. Dynamic springs are one way to minimize invasiveness while achieving favorable results. The purpose of this study was to show the safety and efficacy of dynamic springs with resorbable foot plates for treatment of metopic suture abnormalities in a swine model. The study population consisted of twelve 20 kg Chester swine. The swine were divided into two treatment groups: four in the sham surgery group and eight in the stainless steel spring group. Postoperative analysis consisted of evaluation of the skull growth over time and integrity of the foot plates and underlying dura. The swine, killed at 8 weeks, were examined for spring location in the foot plates, ease of removal of the spring, and postmortem histologic analysis of the bone growth. No morbidity or mortality occurred in the immediate perioperative period secondary to the surgery. Postmortem histologic analysis revealed no infections or complications related to the surgery. Statistical analysis using a mixed linear model with an unstructured variance-covariance matrix was fit. In conclusion, this study confirms the efficacy and safety of the spring-mediated cranioplasty at the metopic suture with use of resorbable foot plates in a swine model.

Burn Management in the Developing World: International Volunteerism

The burden of burn injury falls predominantly on the world's poor, with low-income and middle-income countries accounting for 96% of burn injuries. These vulnerable populations are the least likely to have access to adequate medical care and are the most reliant on volunteer organizations. Every underserved area has a unique set of needs, circumstances, customs, resources, and challenges. The authors' intent is to provide an additional resource for volunteer surgeons who are interested in treating burns. This article reviews planning, organizing, and participating in a burn surgical mission trip.

Dupuytren Cords Do Not Undergo Significant Histopathological Change After Collagenase Clostridium Histolyticum Injection

Background: Dupuytren disease creates thickened cords of the palmar fascia, leading to progressive flexion contractures that severely hinder hand function. Collagenase clostridium histolyticum (CCH) injection is a common, minimally invasive alternative to surgical excision of these cords. The impact of CCH injection on the histological architecture of Dupuytren cords has not been studied extensively. Methods: A series of 10 CCH-injected cords were evaluated histologically. Cellularity, architecture, and connective tissue organization were compared against uninjected Dupuytren cords and normal palmar fascia. Results: No significant histopathological differences between CCH-injected and CCH-uninjected cords were identified. Conclusions: Dupuytren cords do not demonstrate histological changes with prior exposure to CCH.

Innovating Flexor Tendon Repair Training with a Three-dimensional Printed Model

Background

Flexor tendon repair is a technically demanding procedure, with functional outcome directly proportional to skillful execution. A repair must be strong to manage early mobilization and precise to allow for gliding through the tendon sheath. As a result, junior residents face a steep learning curve that may be mitigated by exposure to surgical simulators.

Methods

To facilitate flexor tendon repair training, a surgical training device and accompanying instructional video were developed. Simulation workshops were held for junior orthopedic and plastic surgery residents (n = 11). To objectively assess validity of the curriculum, study participants performed cadaveric flexor tendon repairs before and after the workshop. Anonymous recordings of these repairs were graded by two certified hand surgeons. Additionally, a tensometer was used to measure strength of repair.

Results

Model realism, educational utility, and overall usefulness rated high: 4.6 ± 0.52 95% confidence interval (CI) for realism, 4.9 ± 0.42 95% CI for device, 4.7 ± 0.96 95% CI for video, and 4.9 ± 0.66 95% CI overall. Subjective confidence increased after the training session (73% ranked "moderately" or "extremely"). Likewise, scores given by the surgeons grading the repairs improved for overall quality and time of repair (pre: 2.77 ± 0.61, post: 4.22 ± 0.56, P= 0.0002). Strength of repair did not change (P = 0.87).

Conclusions

The proposed three-dimensional surgical simulator for flexor tendon repair is realistic and useful, with improved surgical technique and improved confidence demonstrated after use. This design can be three-dimensionally printed en masse and provide value to hand surgery training curriculum.