Stable or seral? Fire-driven alternative states in aspen forests of western North America.

As important centres for biological diversity, aspen forests are essential to the function and aesthetics of montane ecosystems in western North America. Aspen stands are maintained by a nuanced relationship with wildfire, although in recent decades aspen mortality has increased. The need to understand the baseline environmental conditions that favour aspen is clear; however, long-term fire history reconstructions are rare due to the scarcity of natural archives in dry montane settings. Here, we analyse a high-resolution lake sediment record from southwestern, Utah, USA to quantify the compositional and burning conditions that promote stable (or seral) aspen forests. Our results show that aspen presence is negatively correlated with subalpine fir and that severe fires tend to promote persistent and diverse aspen ecosystems over centennial timescales. This information improves our understanding of aspen disturbance ecology and identifies the circumstances where critical transitions in montane forests may occur.

Limber Pine (Pinus flexilis James), a Flexible Generalist of Forest Communities in the Intermountain West.

As forest communities continue to experience interactions between climate change and shifting disturbance regimes, there is an increased need to link ecological understanding to applied management. Limber pine (Pinus flexilis James.), an understudied species of western North America, has been documented to dominate harsh environments and thought to be competitively excluded from mesic environments. An observational study was conducted using the Forest Inventory and Analysis Database (FIAD) to test the competitive exclusion hypothesis across a broad elevational and geographic area within the Intermountain West, USA. We anticipated that competitive exclusion would result in limber pine's absence from mid-elevation forest communities, creating a bi-modal distribution. Using the FIAD database, limber pine was observed to occur with 22 different overstory species, which represents a surprising number of the woody, overstory species commonly observed in the Intermountain West. There were no biologically significant relationships between measures of annual precipitation, annual temperature, or climatic indices (i.e. Ombrothermic Index) and limber pine dominance. Limber pine was observed to be a consistent component of forest communities across elevation classes. Of the plots that contained limber pine regeneration, nearly half did not have a live or dead limber pine in the overstory. However, limber pine regeneration was greater in plots with higher limber pine basal area and higher average annual precipitation. Our results suggest limber pine is an important habitat generalist, playing more than one functional role in forest communities. Generalists, like limber pine, may be increasingly important, as managers are challenged to build resistance and resilience to future conditions in western forests. Additional research is needed to understand how different silvicultural systems can be used to maintain multi-species forest communities.

Surgical outcomes of gigantomastia breast reduction superomedial pedicle technique: a 12-year retrospective study.

INTRODUCTION: Reduction mammoplasty in patients with gigantomastia can prove a challenge for the plastic surgeon. Although several techniques have been described to reduce these very large breasts, they can often result in compromise of the nipple-areola complex (NAC), including necrosis, decreased sensation, and inability to breastfeed. The superomedial pedicle (SMP) reduction mammoplasty technique has been demonstrated as a safe and effective method of reduction in cases of mild to moderate hypertrophy. The aim of this study was to determine the risks of SMP in patients with gigantomastia (resection weight >1000 g/breast) at our institution. METHODS/TECHNIQUE: A retrospective study of all patients who underwent reduction mammoplasty with SMP technique by 8 surgeons at a single institution between 1999 and 2011 was performed. Patient demographics, preoperative breast measurements, and perioperative data were analyzed. Exclusion criteria were a reduction mammoplasty specimen weight of less than 1000 g. RESULTS/COMPLICATIONS: Our results show that 200 of 1750 patients who underwent SMP during the study period met the criteria. The average age at the time of the reduction was 39 years. The average body mass index was 36 kg/m. The average sternal notch to nipple distance was 35.5 cm for the right breast and 35.6 cm for the left breast. Average breast resection weight was 1277 g for the right and 1283 g for the left. Average NAC transposition was 11.25 cm for the right breast and 11.40 cm for the left breast. Twenty-one (10.5%) patients experienced partial necrosis of the NAC and 98% of the patients subjectively reported normal NAC sensation postoperatively. All patients exhibited good breast shape and projection postoperatively. CONCLUSIONS: Our study shows that SMP reduction mammoplasty in patients with gigantomastia is a safe and effective reduction mammoplasty technique and is associated with low risk for NAC necrosis with good breast shape.

Safety of antiadhesion barriers in hand surgery.

INTRODUCTION: Adhesions are a major cause of complications and need for repeat surgery in the hand and wrist. They are indication for tenolysis and cause prolonged need for therapy and inability to regain full hand motion. Minimizing adhesions in the hand and wrist would greatly improve surgery, by decreasing cost as well as improved outcome and postoperative function. Antiadhesion barriers, products consisting of hyaluronic acid and methylcellulose were originally advocated for its use in the peritoneal cavity for prevention of adhesions-initially by gynecologist, then general, trauma, and colorectal surgeons. Recently, several authors have looked at its use in animals for prevention of adhesions in regard to tendons, in particular in chickens and rabbits. However, no human studies exist in the literature that shows statistical efficacy or discussing its safety. METHODS: All cases of tendon repairs in the hand and wrist from January 2009 to January 2012 with an antiadhesion barrier placed by a single plastic/hand surgeon at our medical center were evaluated for complications and outcomes. Fourteen patients were identified over this period; demographic data and comorbidities were examined.All patients were placed in blocking splints postoperatively and discharged with 5 days of antibiotics. RESULTS: Of the 14 patients identified over this period, 1 was female and 13 were male. Age of patients ranged from 13 to 74 years. Comorbidities evaluated included diabetes, hypertension, previous wrist or hand injuries or surgery, arthritis, and tobacco use. There was 1 postoperative wound infection with minimal wound separation which resolved with oral antibiotics and Xeroform dressing. One patient experienced spastic muscle disease leading to rerupture of tendon repair. Remainder of patients did not experience any wound complications. No patients required tenolysis after use of the antiadhesion barriers. CONCLUSIONS: Antiadhesion barriers are safe to use in humans for hand/wrist surgery. Studies to evaluate efficacy will require larger numbers of patients, but have already begun at our medical center. According to data from animal studies, antiadhesion barriers should serve as a useful tool for the decrease or even prevention of adhesion formation in the wrist and hand.

Use of radial artery perforator flap from burn-injured tissues.

The hands and forearms are frequent sites of burn injury, and due to the high concentration of superficial tendons, bones, and joints, flaps are frequently needed to cover defects in these areas. We present a patient who suffered remote electrical injury to the right forearm which later developed into an open wound with exposed tendon. Successful coverage of this defect was accomplished with an islanded fasciocutaneous flap based on perforating arterial branches of the radial artery, which was harvested from an area of burn injury. Surgical treatment of hand and forearm wounds with axial pedicled flaps from areas of burn injury have been reported, but to our knowledge no reports describe the use of perforator flaps.

Mastectomy with breast reconstruction in previously augmented patients: indications for implant removal.

Surgeons performing breast reconstruction in previously augmented patients can either leave the preexisting implant in place and incorporate the implant into the reconstruction, or remove the implant, usually performing an implant exchange. The focus of this study is to identify indications for implant removal in previously augmented patients undergoing mastectomy with breast reconstruction. We performed a retrospective chart review of patients who underwent breast reconstruction from 1997-2007 at University of Alabama, Birmingham Medical Center. Of these patients, 54 had previous augmentation with silicone or saline implants. Twenty-two of these underwent bilateral breast reconstruction, making a total of 76 reconstructed breasts. Patients were followed for a mean of 2.1 years (range 0.1-5.1 years). The mean body mass index was 23.0 (range 18-30). Implants were explanted in all but one patient. Reasons for implant removal or exchange included subglandular position (n = 39), aged silicone implant (n = 50), rupture or leak (n = 24), implant exposure (n = 1), and infection (n = 1). Some patients had more than one reason for explantation. We recommend removal of preexisting implants for patients who have implants in a subglandular position, ruptures or leaks, site infections, implant exposures, capsular contractures, pain, indolent seromas, aged silicone implants, poor cosmesis, plans for or history of radiotherapy, and close proximity of tumor to implant. We also remove implants to respect patient preferences and to achieve symmetry in our reconstruction. Consequently, we find in our practice that most of previously augmented patients who undergo breast reconstruction will also undergo implant removal.

Radiation injury and the hand surgeon.

The human hand has been affected by ionizing radiation accidents than any other organ. Hand surgeons should understand the pathophysiology and appropriate management of various types of radiation injury. This article outlines the history and epidemiology of ionizing radiation injury to the hand, basic aspects of radiobiology, and principles of management for injury resulting from fluoroscopy, nuclear accidents or weapons, and other sources.

Athletic pubalgia: definition and surgical treatment.

INTRODUCTION: Athletic pubalgia, or "sports hernia," affects people actively engaged in sports. Previously described in high-performance athletes, it can occur in recreational athletes. It presents with inguinal pain exacerbated with physical activity. Examination reveals absence of a hernia with pubic point tenderness accentuated by resisted adduction of the hip. Diagnosis is by history and physical findings. Treatment with an internal oblique flap reinforced with mesh alleviates symptoms. METHODS: A retrospective review from December 1998 to November 2004 for patients with athletic pubalgia who underwent operative repair was performed. Descriptive variables included age, gender, laterality, sport, time to presentation, outcome, anatomy, and length of follow-up. RESULTS: Twelve patients, 1 female, with median age 25 years were evaluated. Activities included running (33%), basketball (25%), soccer (17%), football (17%), and baseball (8%). The majority were recreational athletes (50%). Median time to presentation was 9 months, with a median 4 months of follow-up. The most common intraoperative findings were nonspecific attenuation of the inguinal floor and cord lipomas. All underwent open inguinal repair, with 9 being reinforced with mesh. Four had adductor tenotomy. Results were 83.3% excellent and 16.7% satisfactory. All returned to sports. CONCLUSION: Diagnosis of athletic pubalgia can be elusive, but is established by history and physical examination. It can be found in recreational athletes. An open approach using mesh relieves the pain and restores activity.

Comorbidity trends in patients requiring sternectomy and reconstruction.

INTRODUCTION: The predisposing risk factors for sternal wound infection have been well delineated. However, the indications and comorbidity of patients who require cardiac surgery via the median sternotomy approach have changed over time and subsequently have changed the patient population presenting with sternal wound complications. These trends in cardiac surgery may require an adjustment of the plastic surgical approach and methods to optimize outcomes in the patient population. METHODS: A retrospective review was performed to identify patients who had undergone sternectomy or sternal debridement followed by flap coverage. A total of 93 cases performed between 1999 and 2004 examined to collect data about the initial presentation, operative procedure, and postoperative care of each patient. The data were then analyzed to identify population characteristics using logistic regression variables to determine univariate and adjusted (multivariable) measures of association with mortality. RESULTS: Results of the review indicated that 53% of the patients were male and 47% were female, with a median age of 62 years. Preoperative comorbidities included 64% of the patients were over age 60, 43% had diabetes, 51% had hypertension, 13% had renal insufficiency, and 6% were transplant recipients. The method of reconstruction varied, but the majority were pectoralis advancement flaps. Of the patients who underwent debridement and reconstruction, there was a 16% 30-day mortality. Among these mortalities, the distribution was 33% (5/15) male and 66% (10/15) female. CONCLUSIONS: Though the incidence of sternal wound problems is rare (about 1%-5%), there is a significant population of older, renal-insufficient, malnourished patients who present days or weeks after one would normally diagnose and treat a deep sternal wound infection who have a significant mortality rate. Appropriate identification of risk factors, preoperative management and timing for aggressive surgical treatment is required to maximize successful outcomes in this problematic patient population.

Diversity, complexity and interactions: an overview of Rocky Mountain forest ecosystems.

This overview of Rocky Mountain forest ecosystems characterizes some of the major types, processes and management issues in the region. There are large ranges in edaphic conditions and striking environmental gradients, all interacting to influence the distribution of species, the nature of communities and disturbance regimes. The discussion focuses on the central role of disturbance and how understanding disturbance regimes influences the search for effective approaches to stewardship.

Sapwood area ofPinus contorta stands as a function of mean size and density.

An indirect test of the relationship between leaf area and the combination of mean size and density is made in stands of lodgepole pine (Pinus contorta Dougl.). Total sapwood cross-sectional area of these stands is a function of the product of density and mean diameter raised to an exponent of about 1.6. Results from other studies, representing four species, suggest that this relationship between sapwood area and the combination of mean size and density may be general. The implications of the relationship are discussed in the context of evapotranspiration, competition and self-thinning.