Tissue oxygenation, anemia, and perfusion in relation to wound healing in surgical patients

Flexible thread-based electrochemical sensors for oxygen monitoring

Oxygen plays a key role in human physiology and is abnormally modulated in various disease pathologies making its in situ monitoring quite important. Most oxygen sensors are not able to measure oxygen levels deep inside the tissue or have mismatched electrode-tissue interfaces. In this study we developed a flexible thread-based oxygen sensor that combines the unique advantages of minimal invasiveness and superior flexibility offering the possibility for tissue integration. The sensor is featured by a simple and low-cost fabrication approach which allows for measuring the overall oxygen concentration either over a large surface area or locally at any spot in any three-dimensional environment with high spatial accuracy and high sensitivity. The sensor can sensitively detect dissolved oxygen levels within the physiological range of tissue oxygenation. The sensor's performance is insensitive to pH variation from 5.8 to 8.0. The sensor shows good repeatability and stability over a period of one week in phosphate buffered saline. In addition, the signal variation is less than 10% after hundreds of cycles of physical bending. Using a hydrogel-based tissue model the sensor has been shown to probe dissolved oxygen levels at different spatial locations inside a tissue-like environment.

Peri-incisional perfusion does not differ between running versus interrupted Allgöwer-Donati suture technique in ankle fracture surgery: a pilot randomized controlled trial of wound perfusion

Objectives:

To compare peri-incisional perfusion, perfusion impairment and wound closure time between the conventional interrupted Allgöwer-Donati (IAD) technique and a modified running Allgöwer-Donati (RAD) technique in ankle fracture surgery.

Design:

Prospective, randomized controlled clinical trial.

Setting:

Level I and II trauma centers.

Patients:

Twenty-five healthy adults with ankle fractures (AO/OTA 44-A, 44-B, or 44-C) between November 2017 and December 2018. (Of 26 patients enrolled in this study, 1 was lost to follow-up.)

Intervention:

Participants were randomized into the IAD or the RAD group (13 patients each). All participants were followed for at least 3 months after surgery to assess for wound complications.

Main Outcome Measurements:

Skin perfusion was assessed immediately after wound closure with laser-assisted indocyanine green angiography. Wound closure time, mean incision perfusion, and mean perfusion impairment were measured and compared with analysis of variance. Alpha = 0.05.

Results:

The RAD technique was significantly faster in terms of mean (± standard deviation) wound closure time (6.2 ± 1.4 minutes) compared with the IAD technique (7.3 ± 1.4 minutes) (P = 0.047). We found no differences in mean incision perfusion and mean perfusion impairment (all, P > 0.05).

Conclusion:

The IAD and RAD techniques resulted in similar peri-incisional perfusion and perfusion impairment. Closure time was significantly shorter for the RAD technique compared with the IAD technique.

Level of Evidence:

I

Preoperative anemia and surgical outcomes following laparotomy in a resource-limited setting

INTRODUCTION

Anemia is a common and potentially modifiable condition in sub-Saharan Africa. We sought to determine the role of preoperative anemia on post laparotomy abdominal complications.

METHODS

We conducted a six-month prospective, observational study of patients age >12 years following laparotomy at a tertiary hospital in Malawi. The outcome was the occurrence of abdominal complications. Poisson regression analyses estimated the risk of abdominal complications in patients with moderate/severe anemia.

RESULTS

Of 280 patients, most were male (76.4%) with median age of 35 years (IQR 24-50). Abdominal complications developed in 34 patients (15.2%). Of the 224 patients with known preoperative hemoglobin 54 (20.7%) were moderately or severely anemic at the time of surgery. Patients with moderate-to-severe anemia had an increased risk of abdominal complications (RR 4.44, 95% CI 2.0-9.6).

CONCLUSION

Anemia is a common but modifiable comorbidity among laparotomy patients and independently increases the risk of abdominal complications.

Aseptic Reoperations Within 1 Year of Primary Total Knee Arthroplasty Markedly Increase the Risk of Later Periprosthetic Joint Infection

BACKGROUND

Despite the high rate of success of primary total knee arthroplasty (TKA), some patients are candidates for early aseptic reoperation. The goal of this study is to evaluate the risk of subsequent periprosthetic joint infection (PJI) in patients treated with an aseptic reoperation within 1 year of primary TKA.

METHODS

A retrospective review of our total joint registry compared 249 primary TKAs requiring an aseptic reoperation within 1 year following index arthroplasty to a control group of 17,867 TKAs not requiring reoperation within 1 year. Patients were divided into groups based on time from index TKA: (1) 90 days or less (114 TKAs) and (2) 91 to 365 days (135 TKAs). Mean age was 68 years with 57% female. Mean follow-up was 7 years.

RESULTS

At 2 years postoperatively, patients undergoing an aseptic reoperation within 90 days subsequently had a 9% PJI rate, while patients undergoing an aseptic reoperation between 91 and 365 days subsequently had a 3% PJI rate. The control group had a 0.4% PJI rate. Compared to the control group, patients undergoing an aseptic reoperation within 90 days had an elevated risk of PJI (hazard ratio, 9; P < .0001), as did patients who had a reoperation between 91 and 365 days (hazard ratio, 4; P < .0001).

CONCLUSION

Aseptic reoperation within 1 year of primary TKA was associated with a notably increased risk of subsequent PJI.

Abdominal Cutaneous Thermography and Perfusion Mapping after Caesarean Section: A Scoping Review

Introduction: Caesarean section (CS) is the most prevalent surgical procedure in women. The incidence of surgical site infection (SSI) after CS remains high but recent observations of CS wounds using infrared thermography has shown promise for the technique in SSI prognosis. Although thermography is recognised as a 'surrogate' of skin perfusion, little is known of the relationship between skin temperature and skin perfusion in the context of wound healing. Aim: To assess the extent of literature regarding the application of infrared thermography and mapping of abdominal cutaneous perfusion after CS. Methods: Wide eligibility criteria were used to capture all relevant studies of any design, published in English, and addressing thermal imaging or skin perfusion mapping of the abdominal wall. The CINAHL and MEDLINE databases were searched, with two independent reviewers screening the title and abstracts of all identified citations, followed by full-text screening of relevant studies. Data extraction from included studies was undertaken using a pre-specified data extraction chart. Data were tabulated and synthesised in narrative format. Results: From 83 citations identified, 18 studies were considered relevant. With three additional studies identified from the reference lists, 21 studies were screened via full text. None of the studies reported thermal imaging and cutaneous perfusion patterns of the anterior abdominal wall. However, two observational studies partially met the inclusion criteria. The first explored analysis methodologies to 'interrogate' the abdominal thermal map. A specific thermal signature ('cold spots') was identified as an early 'flag' for SSI risk. A second study, by the same authors, focusing on obesity (a known risk factor for SSI after CS) showed that a 1 °C lower abdominal skin temperature led to a 3-fold odds of SSI. Conclusion: There is a significant gap in knowledge on how to forewarn of wound complications after CS. By utilising the known association between skin temperature and blood flow, thermographic assessment of the wound and adjacent thermal territories has potential as a non-invasive, independent, imaging option with which to identify tissue 'at risk'. By identifying skin 'hot' or 'cold' spots, commensurate with high or low blood flow regions, there is potential to shed light on the underlying mechanisms leading to infective and non-infective wound complications.

Impact of Skin Suture Pattern on Incision Perfusion Using Intraoperative Laser Angiography: A Randomized Clinical Trial of Patients With Ankle Fractures

OBJECTIVES

To assess which skin suture pattern-simple, vertical mattress, horizontal mattress, Allgöwer-Donati (AD), or running subcuticular-enables the greatest degree of perfusion as measured by indocyanine green laser angiography after ankle fracture surgery.

DESIGN

Prospective, randomized.

SETTING

Level 1 Academic Trauma Center.

PATIENTS/PARTICIPANTS

Seventy-five patients undergoing ankle fracture surgery were prospectively randomized to 1 of 5 skin suture patterns (n = 15 per cohort). Patient demographics and operative parameters were similar between groups.

MAIN OUTCOME MEASUREMENTS

Skin perfusion was assessed intraoperatively after skin closure using indocyanine green laser angiography and quantified in fluorescence units. Two perfusion values were collected: (1) mean incision perfusion was the mean of 10 points along the incision and (2) mean perfusion impairment was the perfusion difference between the incision and the skin adjacent to it. We also collected a postoperative patient scar assessment score.

RESULTS

Running subcuticular closure had significantly better mean incision perfusion than all other closure patterns. Mean perfusion impairment also favored running subcuticular closure, which was significantly lower than all other suture patterns except AD. We found no patient perceived cosmetic differences between the 5 suture pattern types.

CONCLUSIONS

Running subcuticular suture pattern resulted in the greatest incision perfusion than simple, horizontal mattress, vertical mattress, and AD techniques after ankle fracture fixation.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Effect of azygos arch preservation during thoracoscopic esophagectomy on facilitation of postoperative refilling

PURPOSE

In esophageal cancer surgery, the significance of preserving the azygos arch during thoracoscopic esophagectomy remains unknown. To determine the significance, we examined the difference in postoperative courses between patients who underwent an azygos arch-preserving technique and patients whose azygos arch had been dissected.

METHODS

We retrospectively analyzed 119 patients with esophageal cancer who underwent thoracoscopic esophagectomy from January 2017 to December 2019. Statistical tests, including univariate or multivariate analyses and propensity score-matched analysis, were performed focusing on changes in fluid balance caused by the preservation of the azygos arch.

RESULTS

The azygos arch was preserved in 65 patients and dissected in 54 patients. Urine output on postoperative day 2 was higher, and the IN-OUT balance on postoperative day 2 or accumulated IN-OUT balance up to postoperative day 2 tended to be lower in the azygos arch-preserving group than in the dissected group. The azygos arch-preserving technique did not affect the number of dissected mediastinal lymph nodes.

CONCLUSION

The azygos arch-preserving technique during thoracoscopic esophagectomy facilitated postoperative refilling and avoided postoperative fluid excess. This technique might be a novel minimally invasive option for an otherwise highly invasive esophageal cancer surgery.

A Quality Improvement Initiative to Improve Perioperative Hypothermia Rates in the NICU Utilizing Checklists

Premature infants are at high risk for heat loss. Infants undergoing surgical procedures outside of the neonatal intensive care unit have an increased risk of hypothermia. Hypothermia can lead to delayed recovery, hypoglycemia, metabolic acidosis, sepsis, and emotional stress for the parents. We aimed to reduce the incidence of hypothermia for infants undergoing surgical procedures from a baseline of 44.4% to less than 25% over 3 years (2016–2018) with the utilization of a checklist and education.

Correlation between Intraoperative Fluid Administration and Outcomes of Pancreatoduodenectomy

Background

Intraoperative fluid (IOF) administration plays an important role during major abdominal surgery although increased fluid intake can adversely influence postoperative outcomes. However, the effect of the IOF rate on the outcomes of pancreatoduodenectomy (PD) is unclear.

Methods

151 patients, who underwent PD at Binzhou Medical University Hospital between January 2010 and May 2017, were categorized into three groups according to IOF rates (ml/kg/hr): restricted (<10, n = 47), standard (10–15, n = 76), and liberal (>15, n = 28).

Results

The overall postoperative morbidity was 56.95%. The incidence of postoperative pancreatic fistula (POPF) was 11.26%. The in-hospital mortality rate was 7.28% with the most common cause being grade C POPF and secondary intra-abdominal infections. The patients in the liberal group had significantly higher incidences of POPF (25%) and respiratory complications (21.43%). The other outcome parameters such as recovery of bowel function, hospital stay, and postoperative daily drainage were similar among the groups. Multivariable analysis confirmed the IOF rate to be most strongly associated with POPF (odds ratio: 5.195, confidence interval: 1.142–23.823, P = 0.023) and respiratory complications (odds ratio: 7.302, confidence interval: 0.676–58.231, P = 0.025).

Conclusions

The IOF rate significantly affects the incidence of POPF and respiratory complications after PD. Careful patient-oriented fluid therapy may help to prevent these complications.

Personalised haemodynamic management targeting baseline cardiac index in high-risk patients undergoing major abdominal surgery: a randomised single-centre clinical trial

BACKGROUND

Despite several clinical trials on haemodynamic therapy, the optimal intraoperative haemodynamic management for high-risk patients undergoing major abdominal surgery remains unclear. We tested the hypothesis that personalised haemodynamic management targeting each individual's baseline cardiac index at rest reduces postoperative morbidity.

METHODS

In this single-centre trial, 188 high-risk patients undergoing major abdominal surgery were randomised to either routine management or personalised haemodynamic management requiring clinicians to maintain personal baseline cardiac index (determined at rest preoperatively) using an algorithm that guided intraoperative i.v. fluid and/or dobutamine administration. The primary outcome was a composite of major complications (European Perioperative Clinical Outcome definitions) or death within 30 days of surgery. Secondary outcomes included postoperative morbidity (assessed by a postoperative morbidity survey), hospital length of stay, mortality within 90 days of surgery, and neurocognitive function assessed after postoperative Day 3.

RESULTS

The primary outcome occurred in 29.8% (28/94) of patients in the personalised management group, compared with 55.3% (52/94) of patients in the routine management group (relative risk: 0.54, 95% confidence interval [CI]: 0.38 to 0.77; absolute risk reduction: -25.5%, 95% CI: -39.2% to -11.9%; P<0.001). One patient assigned to the personalised management group, compared with five assigned to the routine management group, died within 30 days after surgery (P=0.097). There were no clinically relevant differences between the two groups for secondary outcomes.

CONCLUSIONS

In high-risk patients undergoing major abdominal surgery, personalised haemodynamic management reduces a composite outcome of major postoperative complications or death within 30 days after surgery compared with routine care.

CLINICAL TRIAL REGISTRATION

NCT02834377.

General treatment principles for fracture-related infection: recommendations from an international expert group

Fracture-related infection (FRI) remains a challenging complication that creates a heavy burden for orthopaedic trauma patients, their families and treating physicians, as well as for healthcare systems. Standardization of the diagnosis of FRI has been poor, which made the undertaking and comparison of studies difficult. Recently, a consensus definition based on diagnostic criteria for FRI was published. As a well-established diagnosis is the first step in the treatment process of FRI, such a definition should not only improve the quality of published reports but also daily clinical practice. The FRI consensus group recently developed guidelines to standardize treatment pathways and outcome measures. At the center of these recommendations was the implementation of a multidisciplinary team (MDT) approach. If such a team is not available, it is recommended to refer complex cases to specialized centers where a MDT is available and physicians are experienced with the treatment of FRI. This should lead to appropriate use of antimicrobials and standardization of surgical strategies. Furthermore, an MDT could play an important role in host optimization. Overall two main surgical concepts are considered, based on the fact that fracture fixation devices primarily target fracture consolidation and can be removed after healing, in contrast to periprosthetic joint infection were the implant is permanent. The first concept consists of implant retention and the second consists of implant removal (healed fracture) or implant exchange (unhealed fracture). In both cases, deep tissue sampling for microbiological examination is mandatory. Key aspects of the surgical management of FRI are a thorough debridement, irrigation with normal saline, fracture stability, dead space management and adequate soft tissue coverage. The use of local antimicrobials needs to be strongly considered. In case of FRI, empiric broad-spectrum antibiotic therapy should be started after tissue sampling. Thereafter, this needs to be adapted according to culture results as soon as possible. Finally, a minimum follow-up of 12 months after cessation of therapy is recommended. Standardized patient outcome measures purely focusing on FRI are currently not available but the patient-reported outcomes measurement information system (PROMIS) seems to be the preferred tool to assess the patients' short and long-term outcome. This review summarizes the current general principles which should be considered during the whole treatment process of patients with FRI based on recommendations from the FRI Consensus Group.Level of evidence: Level V.

The Lawrence D. Dorr Surgical Techniques & Technologies Award: Aseptic Reoperations Within One Year of Primary Total Hip Arthroplasty Markedly Increase the Risk of Later Periprosthetic Joint Infection

BACKGROUND

Despite the success of primary total hip arthroplasties (THAs), some patients will require an aseptic reoperation within 1 year of the index THA. The goal of this study is to evaluate the risk of subsequent periprosthetic joint infection (PJI) in patients undergoing an aseptic reoperation within 1 year of a primary THA.

METHODS

A retrospective review utilizing our institutional joint registry identified 211 primary THAs requiring aseptic reoperation within 1 year following index arthroplasty. A control group of 15,357 primary THAs not requiring reoperation within 1 year was identified. Patients were divided into groups based on time from primary THA to reoperation: (1) within 90 days (n = 112 THAs; 40% for dislocation, 34% for periprosthetic fracture) or (2) 91-365 days (n = 99 THAs; 37% for dislocation, 29% for periprosthetic fracture). Mean follow-up was 7 years.

RESULTS

Patients undergoing an aseptic reoperation within 90 days had a PJI rate of 4.8% at 2 years, while the 91-365 day group had a PJI rate of 3.2% at 2 years. The control group had a PJI rate of 0.2% at 2 years. Employing a multivariate analysis, reoperation within 90 days of index arthroplasty had an elevated risk of PJI (hazard ratio 8, P < .001) as did a reoperation between 91 and 365 days (hazard ratio 13, P < .001).

CONCLUSION

Aseptic reoperations within 1 year following primary THA resulted in an 8- to 13-fold increased risk of subsequent PJI. The risk was similar whether the aseptic reoperation was early (within 90 days) or later (91-365 days).

LEVEL OF EVIDENCE

Level III (Prognostic).

Role of oxygen in wound healing

Not only does oxygen play an essential role in each stage of the wound healing process. It also helps to increases host resistance to infection. Any impairment to the oxygen supply can therefore delay healing. This article explores the affects of oxygen on the wound cells and tissue, and explains how an adequate supply is required for granulation tissue formation and epithelialisation to occur

[Perioperative fluid management]

An appropriate perioperative infusion management is pivotal for the perioperative outcome of the patient. Optimization of the perioperative fluid treatment often results in enhanced postoperative outcome, reduced perioperative complications and shortened hospitalization. Hypovolemia as well as hypervolemia can lead to an increased rate of perioperative complications. The main goal is to maintain perioperative euvolemia by goal-directed therapy (GDT), a combination of fluid management and inotropic medication, to optimize perfusion conditions in the perioperative period; however, perioperative fluid management should also include the preoperative and postoperative periods. This encompasses the preoperative administration of carbohydrate-rich drinks up to 2 h before surgery. In the postoperative period, patients should be encouraged to start per os hydration early and excessive i.v. fluid administration should be avoided. Implementation of a comprehensive multimodal, goal-directed fluid management within an enhanced recovery after surgery (ERAS) protocol is efficient but the exact status of indovodual items remains unclear at present.

Clinical and histologic tissue responses of skin incisions closed with glycomer 631 and lactomer 9-1 using a subcuticular technique in pigs

BACKGROUND

Glycomer 631 and lactomer 9-1 are absorbable suture materials indicated for soft tissue approximation in non-infected wounds. Pigs are often used as surgical models in translational research; however, reports of tissue reactions to both suture materials in pigs are limited. The aim of this study was to assess clinical and histologic responses of skin incisions closed with a subcuticular technique using glycomer 631 and lactomer 9-1 in pigs.

RESULTS

Skin incisions on 17 pigs were closed with glycomer 631 and lactomer 9-1, and a clinical reactive score (CRS) including erythema, swelling, discharge and dehiscence was calculated on postoperative days 7 and 14. Subcuticular tissue reaction was assessed histologically on postoperative day 14 (the presence of extravascular neutrophils, macrophages, multinucleated giant cells, lymphocytes, fibroblasts, bacterial colonies and the overall severity of the inflammatory response to the suture material), and the cumulative score of the variables was calculated as an aggregate tissue irritation score (ATIS). Tissue samples were examined for suture extrusion and evaluated microbiologically. The clinical reactive score did not differ between the suture materials. Only one ATIS variable, namely the overall severity of the inflammatory response, was lower (p = 0.029) when glycomer 631 was used. Suture extrusion was found in 10/17 of the incisions closed by glycomer 631 and in 7/13 of the incisions closed by lactomer 9-1. Trueperella pyogenes was isolated from the skin and from the area of tissue reaction in six pigs.

CONCLUSIONS

No difference in CRS between the suture materials was observed, and thus both materials may be used for the subcuticular technique in pigs. Glycomer 631 induced less tissue reaction only in terms of the overall severity of the inflammatory response. Suture extrusion was observed in more than 50% of incisions regardless of the suture material, possibly due to a large amount of suture material in the wound. Trueperella pyogenes was the only pathogen isolated from the tissue surrounding the suture material.

Evidence according to Cochrane Systematic Reviews on Alterable Risk Factors for Anastomotic Leakage in Colorectal Surgery

Anastomotic leakage reflects a major problem in visceral surgery, leading to increased morbidity, mortality, and costs. This review is aimed at evaluating and summarizing risk factors for colorectal anastomotic leakage. A generalized discussion first introduces risk factors beginning with nonalterable factors. Focus is then brought to alterable impact factors on colorectal anastomoses, utilizing Cochrane systematic reviews assessed via systemic literature search of the Cochrane Central Register of Controlled Trials and Medline until May 2019. Seventeen meta-anaylses covering 20 factors were identified. Thereof, 7 factors were preoperative, 10 intraoperative, and 3 postoperative. Three factors significantly reduced the incidence of anastomotic leaks: high (versus low) surgeon's operative volume (RR = 0.68), stapled (versus handsewn) ileocolic anastomosis (RR = 0.41), and a diverting ostomy in anterior resection for rectal carcinoma (RR = 0.32). Discussion of all alterable factors is made in the setting of the pre-, intra-, and postoperative influencers, with the only significant preoperative risk modifier being a high colorectal volume surgeon and the only significant intraoperative factors being utilizing staples in ileocolic anastomoses and a diverting ostomy in rectal anastomoses. There were no measured postoperative alterable factors affecting anastomotic integrity.

Optical and Optoacoustic Imaging

The present chapter summarizes progress with optical methods that go beyond human vision. The focus is on two particular technologies: fluorescence molecular imaging and optoacoustic (photoacoustic) imaging. The rationale for the selection of these two methods is that in contrast to optical microscopy techniques, both fluorescence and optoacoustic imaging can achieve large fields of view, i.e., spanning several centimeters in two or three dimensions. Such fields of views relate better to human vision and can visualize large parts of tissue, a necessary premise for clinical detection. Conversely, optical microscopy methods only scan millimeter-sized dimensions or smaller. With such operational capacity, optical microscopy methods need to be guided by another visualization technique in order to scan a very specific area in tissue and typically only provide superficial measurements, i.e., information from depths that are of the order of 0.05-1 mm. This practice has generally limited their clinical applicability to some niche applications, such as optical coherence tomography of the retina. On the other hand, fluorescence molecular imaging and optoacoustic imaging emerge as more global optical imaging methods with wide applications in surgery, endoscopy, and non-invasive clinical imaging, as summarized in the following. The current progress in this field is based on a volume of recent review and other literature that highlights key advances achieved in technology and biomedical applications. Context and figures from references from the authors of this chapter have been used here, as it reflects our general view of the current status of the field.

Relationship of transcutaneous oxygen tension with age and skin elasticity in Korean women

BACKGROUND

Oxygen has several positive effects on the skin, including improving collagen synthesis and accelerating wound healing. However, only a few studies have investigated the relationship between skin oxygenation and skin aging parameters. Therefore, this study aimed to assess the correlation between skin oxygenation and skin aging parameters-elasticity, hydration, sebum, color (lightness, redness), and blood perfusion-in Korean women.

MATERIALS AND METHODS

We evaluated the transcutaneous partial pressure of oxygen, also known as transcutaneous oxygen tension (TcPO₂ ), and skin aging parameters, including elasticity, hydration, sebum, color (lightness or redness), and blood perfusion, in the cheek of 34 healthy women (aged 20-69 years) and assessed the correlation between TcPO₂ and other skin aging parameters using IBM SPSS Statistics 25 software (SPSS Inc).

RESULTS

Facial TcPO₂ was negatively correlated with age (P < .05). There were positive correlations between facial TcPO₂ and elasticity parameters (P < .01). We noted no correlation between facial TcPO₂ and skin lightness; however, skin lightness tended to slightly improve with increasing TcPO₂ . Skin aging parameters, including hydration, sebum, skin redness, and blood perfusion, showed no correlations with TcPO₂ .

CONCLUSION

In Korean women, facial TcPO₂ tends to decrease with increasing age and is positively correlated with gross, net, and biological skin elasticity. Therefore, this study demonstrated that oxygen tension of facial skin can be a major causative factor of skin aging.

Morbid Obesity Is Associated With an Increased Risk of Wound Complications and Infection After Lower Extremity Soft-tissue Sarcoma Resection

BACKGROUND

Obesity is associated with wound complications after lower extremity surgery. Excision of soft-tissue sarcomas is urgent, and unlike the elective surgery, obesity cannot be modified preoperatively. The purpose of this study was to evaluate the effect of obesity on treatment outcome.

METHODS

Six hundred fifty-three patients (343 men; mean age, 56 ± 18 years) with a lower extremity soft-tissue sarcoma were reviewed. The mean body mass index (BMI) was 27.1 ± 5.7 kg/m, with 189 obese patients (29%) having a BMI of ≥30 kg/m and 27 morbidly obese patients (4%) having a BMI of ≥40 kg/m. Complications and functional and oncologic outcomes were compared between groups.

RESULTS

Two hundred eighty-five patients (40%) sustained a postoperative complication, most commonly a dehiscence (n = 175; 24%) and infection (n = 147; 21%). On multivariate analysis, morbid obesity was associated with wound complications (P = 0.002) and infection (P = 0.01). Morbid obesity was not associated with local tumor recurrence (P = 0.56). No difference was found in the mean Toronto Extremity Salvage Score (P = 0.11) or Musculoskeletal Tumor Society (P = 0.41) scores between the groups.

DISCUSSION

Morbid obesity was associated with postoperative wound complications and infection. However, after surgery, obese patients can expect no difference in oncologic outcome, with an excellent functional result.

Does localized iron loss in venous disease lead to systemic iron deficiency? A descriptive pilot study

Haemosiderin deposition in the legs of patients with venous leg ulcers is well established, and several theories suggest this stored iron has a role in disease pathophysiology. In this novel pilot study of patients with chronic venous leg ulcers, we aimed to establish the relationship between wound fluid iron levels, serum iron parameters and healing. Fifteen patients with venous ulcers were included in the study. Blood samples were taken for full blood count and iron studies, while simultaneously wound fluid was obtained from the wound surface using filter paper. Wound areas were measured at initial and 4 week (+/- 2 day) follow-up visits. We found a positive correlation between wound fluid and serum iron (correlation co-efficient 0.27) and those with the lowest wound fluid iron level were also anemic. No association was found between initial wound area and wound fluid iron level but the largest wound areas were found in patients with anemia. Only 38% of patients demonstrated a reduction in wound area during the 4 week study, and 80% of those were not anemic or iron deficient. Conversely in those patients whose wounds did not reduce in size 88% were anemic or iron deficient. These findings demonstrate a previously unrecognized phenomenon of systemic iron store depletion secondary to leaching out of the body in wound exudate. In addition, these results suggest a high prevalence of anemia in patients with chronic venous ulcers, though whether this is cause or effect requires further research. Our findings also suggest that patients with venous ulcers have a high prevalence of iron deficiency and anemia, which appears to be often undiagnosed, and that diagnostic criteria for iron deficiency in patients with chronic wounds need to be revised to reflect the effect of chronic inflammation on iron metabolism.

Drug therapies and delivery mechanisms to treat perturbed skin wound healing

Acute wound healing is an orderly process of four overlapping events: haemostasis, inflammation, proliferation and remodelling. A drug delivery system with a temporal control of release could promote each of these events sequentially. However, acute wound healing normally proceeds very well in healthy individuals and there is little need to promote it. In the elderly and diabetics however, healing is often slow and wounds can become chronic and we need to promote their healing. Targeting the events of acute wound healing would not be appropriate for a chronic wound, which have stalled in the proinflammatory phase. They also have many additional problems such as poor circulation, low oxygen, high levels of leukocytes, high reactive oxygen species, high levels of proteolytic enzymes, high levels of proinflammatory cytokines, bacterial infection and high pH. The future challenge will be to tackle each of these negative factors to create a wound environment conducive to healing.

An overview of the relationship between anaemia, iron, and venous leg ulcers

The factors preventing healing in venous leg ulcers are still not fully understood. Iron-mediated tissue damage has been hypothesised, yet anecdotally anaemia is also thought to have a negative effect on wound healing. This article summarises the current evidence for these theories and their likely effects in the context of venous ulceration. A comprehensive search of the literature was conducted. Studies suggest that a number of forms of iron including haemosiderin and ferritin are implicated in progression of venous disease, ulcer formation, and impaired healing, which is thought to be primarily free radical mediated. There is a paucity of evidence for the role of iron deficiency and anaemia on ulcer healing; however, there is likely to be a highly complex interplay between the damaging effects of iron on local tissues and the negative effects of anaemia-mediated tissue hypoxia. Studies looking at options to increase local oxygen delivery such as topical haemoglobin suggest that this may have an impact on some aspects of healing, but findings are generally inconclusive. There is growing evidence that locally elevated iron levels may have a detrimental effect on ulcer healing and formation; however, more robust research is needed.

Effect of Hyperoxygenation During Surgery on Surgical Site Infection in Colorectal Surgery

Purpose

Despite the use of different surgical methods, surgical site infection is still an important cause of mortality and morbidity in patients and imposes a considerable cost on the healthcare system. Administration of supplemental oxygen during surgery has been reported to reduce surgical site infection (SSI); however, that result is still controversial. This study was performed to evaluate the effect of hyperoxygenation during colorectal surgery on the incidence of wound infection.

Methods

This study was a prospective double-blind case-control study. The main aim of the study was to evaluate the effect of hyperoxygenation during colorectal surgery on the incidence of SSI. Also, secondary outcomes, such as atelectasis, pneumonia, respiratory failure, length of hospital stay, and required hospitalization in the intensive care unit were evaluated.

Results

SSI was recorded in 2 patients (2 of 40, 5%) in the hyperoxygenation group (FiO₂ 80%) and 6 patients (6 of 40, 15%) in the control group (FiO₂ 30%) (P < 0.05). Time of hospitalization was 6 ± 6.4 days in the hyperoxygenation group and 9.2 ± 2.4 days in the control group (P < 0.05).

Conclusion

This study showed a positive effect of hyperoxygenation in reducing SSI in colorectal surgery, especially surgery in an emergency setting. When the low risk, low cost, and effectiveness of this method in patients undergoing a laparotomy are considered, it is recommended for all patients undergoing colorectal surgery.

A Cadaveric Study of Cutaneous Vascular Anatomy about the Elbow Using Computed Tomography Angiography

The posterior approach is a commonly employed exposure of the elbow that provides excellent visualization and efficacy for various orthopedic procedures, including total elbow arthroplasty (TEA) and fracture care. The posterior approach to the elbow has been associated with an increased rate of wound complications, including infection, skin necrosis, and wound dehiscence. Despite an association between these complications and decreased elbow perfusion, data regarding the intrinsic anatomic etiology for preferential complications in this area has been scarcely reported in the literature. This study characterizes the subdermal and cutaneous vascular perfusion about the elbow by describing the predominant direction of circulation, subdermal anastomoses, and volume of perfusion through cadaveric modeling using computed tomography angiography (CTA). Fifteen upper extremity cadaver specimens were prepared with injection of radiographic contrast directly into the axillary artery immediately preceding CTA imaging of each specimen. Sectra IDS7 software for Windows was used for analysis of all images to produce superimposed axial and 3-D reconstructions of each CTA series. From these images it was discerned that the predominant direction of flow in the posterior elbow integument is anterior medial to posterior lateral. Both the posterior medial and posterior lateral subdermal vascular networks emanate from proximally derived medial arterial sources with few anastomoses and minimal collateral perfusion from the anterolateral location. Consequently, it is important to preserve medial subdermal vascular structures to prevent ischemic wound complications. This is especially true in previously incised elbow integuments. Clin. Anat. 32:509-514, 2019. © 2019 Wiley Periodicals, Inc.

Avoiding Postoperative Wound Complications in Total Joint Arthroplasty

Avoidance of early wound complications is critical to the success of total joint arthroplasty. The magnitude of postoperative complications can be as simple as quickly resolving wound drainage, to persistent wound drainage and full-thickness soft tissue necrosis. Persistent postoperative drainage and wound complications can lead to a devastating deep periprosthetic infection. Attention to several steps in the clinical and perioperative pathway should be addressed to avoid this complication including addressing modifiable patient risk factors, implementing meticulous surgical technique, and following an algorithmic approach in response to persistent wound drainage.

Topical oxygen therapy stimulates healing in difficult, chronic wounds: a tertiary centre experience

OBJECTIVE

Oxygen plays a central role in wound healing. Recent technological advances have miniaturised oxygen delivery systems, with novel topical oxygen therapy allowing patients to receive oxygen therapy 24 hours a day while remaining completely mobile. Here we aim to examine the efficacy and safety of continuous topical oxygen diffusion in a 'real-world' setting.

METHODS

Topical oxygen therapy (TOT) was evaluated in patients with chronic, non-healing wounds in a tertiary referral specialist clinic.

RESULTS

The mean wound duration before TOT was 15 months. Regardless of treatment duration, in this previously non-healing group complete wound closure was observed in 32% of the total patients treated with the TOT device. However, optimal wound healing occurred when the device was used for >25 days, with an 83% wound area reduction and 47% wound closure rate seen in venous leg ulcers (VLUs) and a 74% reduction and a 57% wound closure rate in arterial foot ulcers.

CONCLUSION

Use of TOT in chronic wounds stimulates a healing state. In our study, almost half of the previously non-healing wounds closed.

Development of a novel in situ gelling skin dressing: Delivering high levels of dissolved oxygen at pH 5.5

BACKGROUND AND AIMS

Wound healing requires appropriate oxygen and pH levels. Oxygen therapy and pH-modulating treatments have shown positive effects on wound healing. Thus, a dressing, which combines high levels of dissolved oxygen (DO) with the pH of intact skin, may improve wound healing. Our aims were to (1) formulate an in situ gelling dressing with high levels of DO and with the pH level of intact skin, (2) evaluate physical and chemical properties of the dressing, and (3) elucidate basic effects of elevated levels of DO on human skin cells in vitro.

METHODS

A dressing was formulated with 15 to 16 wt% poloxamer 407, acetate buffer, and oxygenated water. Stability of pH and DO, rheology, and shelf life were analysed. Furthermore, in vitro studies of the effect of increased levels of DO were performed.

RESULTS

An in situ gelling wound dressing, with a DO concentration ranging between 25 and 35 mg/L and a pH of 5.5, was formulated. The DO concentration was stable above 22 mg/L for at least 30 hours when applied on a surface at 35°C and covered for directed diffusion into the intended wound area. At storage, the dressing had stable pH for 3 months and stable DO concentration over 30 mg/L for 7 weeks. Increasing DO significantly enhanced intracellular ATP in human skin cells, without changing reactive oxygen species production, proliferation rate, or viability.

CONCLUSION

The developed dressing may facilitate wound healing by delivering controlled and stable oxygen levels, providing adjustable pH for optimized healing, and increasing intracellular ATP availability.

The Effect of Intraoperative Hypothermia on Shoulder Arthroplasty

Limited evidence is available regarding the correlation between intraoperative hypothermia and perioperative complications in shoulder arthroplasty. The purpose of this study was to determine the incidence of intraoperative hypothermia in patients treated with shoulder arthroplasty and its effect on perioperative complications. A retrospective chart review was performed on 657 consecutive patients who underwent shoulder arthroplasty at a single institution between August 2013 and June 2016. Demographic data, surgery-specific data, postoperative complications, length of stay, and 30-day read-mission were recorded. Patients were classified as hypothermic if their mean intraoperative temperature was less than 36°C. Statistical analyses with univariate and multivariate logistic regression were performed to evaluate the association of intraoperative hypothermia with perioperative complications. The incidence of intraoperative hypothermia in shoulder arthroplasty was 52.7%. Increasing age (P=.002), lower body mass index (P=.006), interscalene anesthetic (P=.004), and lower white blood cell count (P<.001) demonstrated increased association with hypothermia. Longer operating room times and increased estimated blood loss were not found to be associated with intraoperative hypothermia. Hypothermia demonstrated no significant association with surgical site infections nor any other perioperative complications. Patients undergoing shoulder arthroplasty showed a high incidence of intraoperative hypothermia. Lower body mass index, increasing age, interscalene anesthetic, and lower white blood cell count were associated with an increased incidence of hypothermia. Contrary to previous studies, intraoperative hypothermia was not found to contribute to perioperative complications in shoulder arthroplasty. [Orthopedics. 2018; 41(4):e523-e528.].

Increased visceral tissue perfusion with heated, humidified carbon dioxide insufflation during open abdominal surgery in a rodent model

Tissue perfusion during surgery is important in reducing surgical site infections and promoting healing. This study aimed to determine if insufflation of the open abdomen with heated, humidified (HH) carbon dioxide (CO2) increased visceral tissue perfusion and core body temperature during open abdominal surgery in a rodent model. Using two different rodent models of open abdominal surgery, visceral perfusion and core temperature were measured. Visceral perfusion was investigated using a repeated measures crossover experiment with rodents receiving the same sequence of two alternating treatments: exposure to ambient air (no insufflation) and insufflation with HH CO2. Core body temperature was measured using an independent experimental design with three treatment groups: ambient air, HH CO2 and cold, dry (CD) CO2. Visceral perfusion was measured by laser speckle contrast analysis (LASCA) and core body temperature was measured with a rectal thermometer. Insufflation with HH CO2 into a rodent open abdominal cavity significantly increased visceral tissue perfusion (2.4 perfusion units (PU)/min (95% CI 1.23-3.58); p<0.0001) compared with ambient air, which significantly reduced visceral blood flow (-5.20 PU/min (95% CI -6.83- -3.58); p<0.0001). Insufflation of HH CO2 into the open abdominal cavity significantly increased core body temperature (+1.15 ± 0.14°C) compared with open cavities exposed to ambient air (-0.65 ± 0.52°C; p = 0.037), or cavities insufflated with CD CO2 (-0.73 ± 0.33°C; p = 0.006). Abdominal visceral temperatures also increased with HH CO2 insufflation compared with ambient air or CD CO2, as shown by infrared thermography. This study reports for the first time the use of LASCA to measure visceral perfusion in open abdominal surgery and shows that insufflation of open abdominal cavities with HH CO2 significantly increases visceral tissue perfusion and core body temperature.

Patient-Related Risk Factors for Infection Following Open Carpal Tunnel Release: An Analysis of Over 450,000 Medicare Patients

PURPOSE

To establish the rate of postoperative infection after open carpal tunnel release (CTR) on a national level using an administrative database and define relevant patient-related risk factors associated with its occurrence.

METHODS

The PearlDiver patient records database was used to query the 100% Medicare Standard Analytic Files retrospectively from 2005 to 2012 for patients undergoing open CTR using Current Procedural Terminology code 64721. Postoperative infection within 90 days of surgery was assessed using both International Classification of Diseases, Ninth Revision codes for diagnoses of postoperative infection or pyogenic arthritis of the wrist and Current Procedural Terminology codes for procedures for these indications, including either open or arthroscopic irrigation and debridement. We used a multivariable binomial logistic regression model that allows for assessment of the independent effect of a variable while controlling for remaining variables to evaluate which patient demographics and medical comorbidities were associated with an increased risk for postoperative infection. Adjusted odds ratios and 95% confidence intervals were calculated for each risk factor, with P < .05 considered statistically significant.

RESULTS

A total of 454,987 patients met all inclusion and exclusion criteria. Of these patients, 1,466 developed a postoperative infection, corresponding to an infection rate of 0.32%. Independent positive risk factors for infection included younger age, male sex, obesity (body mass index of 30 to 40), morbid obesity (body mass index greater than 40), tobacco use, alcohol use, and numerous medical comorbidities including diabetes, inflammatory arthritis, peripheral vascular disease, chronic liver disease, chronic kidney disease, chronic lung disease, and depression.

CONCLUSIONS

The current study reinforced conventional wisdom regarding the the overall low infection rate after CTR and revealed numerous patient-related risk factors that are independently associated with an increased risk of infection after open CTR in patients enrolled in Medicare.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Perioperative Outcomes and Complications in Patients With Heart Failure Following Total Knee Arthroplasty

BACKGROUND

Heart failure (HF) is a common comorbidity in the aging population and they will require major elective surgery. The purpose of this study is to determine if HF is a risk factor for adverse perioperative outcomes and short-term complications following total knee arthroplasty.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was utilized to identify all patients who underwent total knee arthroplasty for osteoarthritis from 2008 to 2014. Any diagnosis other than osteoarthritis was excluded. A total of 111,634 patients were identified and 251 of these patients had a preoperative diagnosis of HF. The main outcomes included operative time, lengths-of-stay, discharge disposition, return to operating room, readmission, and short-term complications, including death.

RESULTS

Patients with HF were found to have longer hospital stays (β = 0.59, 95% confidence interval [CI] 0.12-1.06) following total knee arthroplasty, and were more likely to return to the operating room (odds ratio 2.00, 95% CI 1.01-3.94) and be readmitted (OR 1.88, 95% CI 1.21-2.94). In addition, HF was found to be a risk factor for 1 or more complications (OR 1.41, 95% CI 1.05-1.90), wound dehiscence (OR 4.86, 95% CI 1.68-14.03), and myocardial infarction (OR 4.81, 95% CI 1.90-12.16) postoperatively.

CONCLUSION

Patients with HF are more likely to have a longer length-of-stay, return to the operating room, and be readmitted. Additionally, they have a higher risk for at least one postoperative complication, myocardial infarction, and wound dehiscence.

Reactive Oxygen Species and NOX Enzymes Are Emerging as Key Players in Cutaneous Wound Repair

Our understanding of the role of oxygen in cell physiology has evolved from its long-recognized importance as an essential factor in oxidative metabolism to its recognition as an important player in cell signaling. With regard to the latter, oxygen is needed for the generation of reactive oxygen species (ROS), which regulate a number of different cellular functions including differentiation, proliferation, apoptosis, migration, and contraction. Data specifically concerning the role of ROS-dependent signaling in cutaneous wound repair are very limited, especially regarding wound contraction. In this review we provide an overview of the current literature on the role of molecular and reactive oxygen in the physiology of wound repair as well as in the pathophysiology and therapy of chronic wounds, especially under ischemic and hyperglycemic conditions.

Benefits of maggot debridement therapy on leg ulcers: a literature review

Maggot debridement therapy (MDT) is an effective method for debriding wounds such as leg ulcers, supporting the concept of wound bed preparation ( Dumville et al, 2009 ; Soares et al, 2009 ; Mudge et al, 2014 ). New evidence is emerging to suggest that maggots might contribute to wound healing in other ways. For example, the reduction of biofilms and disinfection of wounds ( Van Der Plas et al, 2008 ; Brown et al, 2012 ; Pritchard and Brown, 2015 ) plus regulation of protease levels ( Chambers et al, 2003 ; Van Der Plas et al, 2009a ; Van Der Plas et al, 2009b ). This review will discuss research exploring new benefits of maggots in the management of individuals with chronic leg ulcers.

A Meta-Analysis and Systematic Review Evaluating Skin Closure After Total Knee Arthroplasty-What Is the Best Method?

BACKGROUND

Many cost drivers of total knee arthroplasty (TKA) have been critically evaluated to meet the heightened quality-associated expectations of performance-based care. However, assessing the efficacy of the different modalities of skin closure has been an underappreciated topic. The present study aims to provide further insight by conducting a meta-analysis and systematic review evaluating the rates of common complications and perioperative quality outcomes associated with different suture and staple skin closure techniques after TKA.

METHODS

The present study was conducted in accordance with both the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement and the Cochrane Handbook for meta-analyses and systematic reviews. Primary outcome measures evaluated rates of common complications associated with primary TKA. Secondary outcome measures evaluated wound closure time, direct surgical costs, and cosmetic and knee function outcomes.

RESULTS

Our meta-analysis demonstrated that skin sutures had a higher likelihood of superficial and deep infections, abscess formation, and wound dehiscence. Conversely, staples had a higher tendency for prolonged wound discharge. A systematic review of wound closure times and overall resource utilization demonstrated that wound closure was faster and more cost-effective with skin staples than sutures.

CONCLUSION

Primary skin incision closure with staples demonstrated lower wound complications, decreased wound closure times, and an overall reduction in resource utilization. Given these outcomes, the use of staples after TKA may have several subtle clinical advantages over sutures.

Acute Wound Complications After Total Knee Arthroplasty: Prevention and Management

Normal wound healing with avoidance of early wound complications is critical to the success of total knee arthroplasty. The severity of acute complications includes less morbid problems, such as quickly resolved drainage and small superficial eschars, to persistent drainage and full-thickness tissue necrosis, which may require advanced soft-tissue coverage. To achieve proper healing, surgeons must respond to persistent drainage by addressing modifiable patient risk factors, using meticulous surgical technique, and implementing an algorithmic approach to treatment.

WHO Needs High FIO2?

World Health Organization and the United States Center for Disease Control have recently recommended the use of 0.8 FIO₂ in all adult surgical patients undergoing general anaesthesia, to prevent surgical site infections. This recommendation has arisen several discussions: As a matter of fact, there are numerous studies with different results about the effect of FIO₂ on surgical site infection. Moreover, the clinical effects of FIO₂ are not limited to infection control. We asked some prominent authors about their comments regarding the recent recommendations.

Normothermia in Arthroplasty

BACKGROUND

Since the initial design of surgical theatres, the thermal environment of the operating suite itself has been an area of concern and robust discussion. In the 1950s, correspondence in the British Medical Journal discussed the most suitable design for a surgeon's cap to prevent sweat from dripping onto the surgical field. These deliberations stimulated questions about the effects of sweat-provoking environments on the efficiency of the surgical team, not to mention the effects on the patient. Although these benefits translate to implant-based orthopedic surgery, they remain poorly understood and, at times, ignored.

METHODS

A review and synthesis of the body of literature on the topic of maintenance of normothermia was performed.

RESULTS

Maintenance of normothermia in orthopedic surgery has been proven to have broad implications from bench top to bedside. Normothermia has been shown to impact everything from nitrogen loss and catabolism after hip fracture surgery to infection rates after elective arthroplasty.

CONCLUSION

Given both the physiologic impact this has on patients, as well as a change in the medicolegal environment around this topic, a general understanding of these concepts should be invaluable to all surgeons.

Excess intraoperative fluid volume administration is associated with pancreatic fistula after pancreaticoduodenectomy: A retrospective multicenter study

Recent studies on perioperative fluid administration in patients undergoing pancreaticoduodenectomy (PD) have suggested that increased fluid loads are associated with worse perioperative outcomes. The purpose of this study was to investigate the relationship between intraoperative fluid (IOF) administration and postoperative pancreatic fistula (POPF), and to determine additional risk factors affecting pancreatic fistula in patients undergoing PD.From 2005 to 2014, a total of 182 patients with various periampullary diseases after PD were reviewed retrospectively at Dongguk University Ilsan Hospital, Chung-Ang University Hospital, and Dongnam Institute of Radiological and Medical Sciences. Patients were assigned to high or low IOF groups based on more or less fluid administration for supplementation of estimated blood loss and maintenance volume (12.5 mL/kg/h) than planned, respectively. The associations between IOF administration, pancreatic fistula development, and perioperative outcomes were evaluated.A total of 98 patients were assigned to the high-IOF group, and 84 to the low-IOF group. Risk factors for pancreatic fistula after univariate analysis were assignment to the high-IOF group, higher preoperative serum hemoglobin level, ampullary or bile duct cancer, pylorus preserving PD, small pancreatic duct, duct-to-mucosa pancreatojejunostomy, use of a stent, and mesh application to pancreatojejunal anastomosis. Among these, assignment to the high-IOF group (hazard ratio [HR] = 5.501, 95% CI 1.624-18.632, P = .006) and a small (<4 mm) pancreatic duct (HR = 4.129, 95% CI 1.569-14.658, P = .035) were identified as independent risk factors for the development of pancreatic fistula after multivariate analysis. However, long-term survival rate did not differ according to IOF group or duct size.Excessive IOF volume administration is associated with an increased incidence of pancreatic fistula after pancreaticoduodenectomy.

Risk Factors for 30-Day Hospital Re-Admission with an Infectious Complication after Lower-Extremity Vascular Procedures

BACKGROUND

Lowering the 30-d re-admission rate after vascular surgery offers the potential to improve healthcare quality. This study evaluated re-admission associated with infections after open and endovascular lower extremity (LE) procedures for peripheral artery disease (PAD).

METHODS

Patients admitted for elective LE procedures for PAD were selected from the Cerner Health Facts^® database. Chi-square analysis evaluated the characteristics of the index admission associated with infection at 30-d re-admission. Multivariable logistic models were created to examine the association of patient and procedural characteristics with infections at re-admission. The microbiology data available at the time of re-admission were evaluated also.

RESULTS

A total of 7,089 patients underwent elective LE procedures, of whom 770 (10.9%) were re-admitted within 30 d. A total of 289 (37.5%) had a diagnosis of infection during the re-admission. These infections included surgical site (14.8%), cellulitis (13.6%), sepsis (8.8%), urinary tract (4.9%), and pneumonia (4.9%). Index stay factors associated with infection at re-admission were fluid and electrolyte disorders, kidney disease, diabetes, previous infection, and chronic anemia. Laboratory results associated with an infection during re-admission were post-operative hemoglobin <8 g/dL, blood urea nitrogen >20 mg/dL, platelet counts >400 × 10³/mcL, glucose >180 mg/dL, and white blood cell count >11.0 × 10³/mcL. Adjusted models demonstrated longer stay, chronic anemia, previous infection, treatment at a teaching hospital, and hemoglobin <8 g/dL to be risk factors for re-admission with infection. Infective organisms isolated during the re-admission stay included Staphylococcus, Enterococcus, Escherichia, Pseudomonas, Proteus, and Klebsiella.

CONCLUSIONS

Infectious complications were associated with more than one-third of all re-admissions after LE procedures. Predictors of re-admission within 30 d with an infectious complication were longer stay, greater co-morbidity burden, hospitalization in teaching facilities, hemoglobin <8 g/dL, and an infection during the index stay. Microbiology examination at re-admission demonstrated gram-negative bacteria in more than 40% of infections. Further evaluation of high-risk vascular patients prior to discharge and consideration of antibiotic administration for gram-negative organisms at the time of re-admission may improve outcomes.

Allgöwer-Donati Versus Vertical Mattress Suture Technique Impact on Perfusion in Ankle Fracture Surgery: A Randomized Clinical Trial Using Intraoperative Angiography

OBJECTIVE

The purpose of this study was to evaluate which primary wound closure technique for ankle fractures affords the most robust perfusion as measured by laser-assisted indocyanine green angiography: Allgöwer-Donati or vertical mattress.

DESIGN

Prospective, randomized.

SETTING

Level 1 Academic Trauma Center.

PATIENTS/PARTICIPANTS

Thirty patients undergoing open reduction internal fixation for ankle fractures were prospectively randomized to Allgöwer-Donati (n = 15) or vertical mattress (n = 15) closure. Demographics were similar for both cohorts with respect to age, sex, body mass index, surgical timing, and OTA/AO fracture classification.

MAIN OUTCOME MEASUREMENTS

Skin perfusion (mean incision perfusion and mean perfusion impairment) was quantified in fluorescence units with laser-assisted indocyanine green angiography along the lateral incision as well as anterior and posterior to the incision at 30 separate locations. Minimum follow-up was 3 months with a mean follow-up 4.7 months.

RESULTS

Allgöwer-Donati enabled superior perfusion compared with the vertical mattress suture technique. Mean incision perfusion for Allgöwer-Donati was 51 (SD = 13) and for vertical mattress was 28 (SD = 10, P < 0.0001). Mean perfusion impairment was less in the Allgöwer-Donati cohort (12.8, SD = 9) compared with that in the vertical mattress cohort (23.4, SD = 14; P = 0.03). One patient in each cohort experienced a wound complication.

CONCLUSIONS

The Allgöwer-Donati suture technique offers improved incision perfusion compared with vertical mattress closure after open reduction internal fixation of ankle fractures. Theoretically, this may enhance soft tissue healing and decrease the risk of wound complications. Surgeons may take this into consideration when deciding closure techniques for ankle fractures.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Goal-directed fluid therapy for reducing risk of surgical site infections following abdominal surgery - A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Surgical site infections (SSIs) become a key indicator of quality of care. This meta-analysis aimed to determine the effect of goal-directed fluid therapy (GDFT) on the risk of SSIs after abdominal surgery.

METHODS

MEDLINE, Embase, CINAHL, Scopus, the Cochrane Controlled Trials Register, and Cochrane Database of Systematic Reviews were searched for randomized controlled trials (RCTs), from inception to May 2016 that compared the incidence of SSIs in abdominal surgical patients with or without GDFT treatment. . Data were pooled and risk ratio (RR) as well as weighted mean differences (WMD) with their 95% confidence intervals (CI) was calculated using either fixed or random effects models, depending on heterogeneity (I²).

RESULTS

A total of 29 eligible RCTs with 5317 patients were included in this analysis. GDFT significantly reduced the incidence of SSIs after abdominal surgery. The pooled RR was 0.74 (95% CI: 0.63 to 0.86) with low heterogeneity (I² = 4%). Length of hospital stay was significantly reduced in the GDFT group (WMD: -1.16 days, 95% CI: -1.92 to -0.40, p = 0.003; I² = 81%).

CONCLUSION

This systematic review suggests that perioperative GDFT is associated with a reduction in the incidence of SSIs after abdominal surgery.