Negative Pressure Wound Therapy - Effects on Sternotomy Wounds and the Intrathoracic Organs

Negative pressure wound therapy (NPWT) has been widely adopted for the treatment of deep sternal wound infections due to its excellent clinical outcome. However, the mechanisms of action and effects on hemodynamics have not been thoroughly elucidated. The aims of the work presented in this thesis were, therefore, to examine the effects of NPWT on sternotomy wounds and on the intrathoracic organs. An uninfected porcine sternotomy wound model was used in all studies. The studies showed that negative pressure is transmitted only to tissues that are in direct contact with the foam dressing and not to deeper parts of the wound or thoracic cavity. As NPWT was applied, a transient increase was seen in the plasma levels of norepinephrine and epinephrine, followed by an increase in the adrenergic co-transmitter neuropeptide Y, which may reflect the effect of NPWT on the intrathoracic organs. Increased levels of the sensory nerve transmitter substance P may result from shearing forces arising from the mechanical effects of the negative pressure. Magnetic resonance imaging showed that cardiac output increased while the cardiac pumping efficiency decreased following sternotomy, and then returned to presternotomy values when the negative pressure resealed the thorax. NPWT contracts the wound and causes macrodeformation of the wound edge tissue. This may contribute to the clinical benefits of NPWT over open-chest treatment, including the stabilizing effect and reduced need for mechanical ventilation. The results of the present work underline the importance of correct placement of the wound filler with regard to pressure transmission. The findings also reduce concerns that NPWT could impair cardiac output, and emphasize the beneficial effects of temporary closure provided by NPWT on restoring the intrathoracic anatomy

Organ-sparing reconstructive surgery in penile cancer: initial experiences at two Swedish referral centres.

Abstract Objective. The aim of this study was to present early outcome data for patients treated for penile cancer with organ-sparing reconstructive surgery at two referral centres in Sweden. Material and methods. Oncological, cosmetic and functional outcome and complications were analysed retrospectively during the period 2011-2013. Twelve patients with non-invasive penile cancer were treated with glans resurfacing (GR), while 15 patients with invasive penile cancer underwent total glansectomy with neoglans reconstruction (TGN). Results. The 12 patients treated with GR had a median age of 66 years (range 35-83 years) and a median follow-up time of 16 months (range 4-40 months). All patients showed carcinoma in situ and negative surgical margins in the final pathology report. The 15 patients treated with TGN had a median age of 71 years (range 37-78 years) and the median follow-up time was 10 months (range 1-25 months). All patients had invasive penile cancer and the surgical margins were negative in all cases except one. Complications occurred in five of the 27 patients (18%), and in most cases these were minor and infection related. No recurrences were seen in either group during follow-up, and all patients except one, who had undergone GR, were satisfied with the functional and cosmetic results. Conclusions. GR and TGN seem to be oncologically safe procedures for treating carefully selected patients with penile cancer, and the functional and cosmetic results are promising. Based on these findings, the authors recommend that penile amputation should only be carried out in patients who are not suitable for organ-sparing reconstructive surgery

Intensive Imaging-based Follow-up of Surgically Treated Localised Renal Cell Carcinoma Does Not Improve Post-recurrence Survival: Results from a European Multicentre Database (RECUR).

The optimal follow-up (FU) strategy for patients treated for localised renal cell carcinoma (RCC) remains unclear. Using the RECUR database, we studied imaging intensity utilised in contemporary FU to evaluate its association with outcome after detection of disease recurrence. Consecutive patients with nonmetastatic RCC (n=1612) treated with curative intent at 12 institutes across eight European countries between 2006 and 2011 were included. Recurrence occurred in 336 patients. Cross-sectional (computed tomography, magnetic resonance imaging) and conventional (chest X-ray, ultrasound) methods were used in 47% and 53%, respectively. More intensive FU imaging (more than twofold) than recommended by the European Association of Urology (EAU) was not associated with improved overall survival (OS) after recurrence. Overall, per patient treated for recurrence remaining alive with no evidence of disease, the number of FU images needed was 542, and 697 for high-risk patients. The study results suggest that use of more imaging during FU than that recommended in the 2017 EAU guidelines is unlikely to improve OS after recurrence. Prospective studies are needed to design optimal FU strategies for the future. PATIENT SUMMARY: After curative treatment for localised kidney cancer, follow-up is necessary to detect any recurrence. This study illustrates that increasing the imaging frequency during follow-up, even to double the number of follow-up imaging procedures recommended by the European Association of Urology guidelines, does not translate into improved survival for those with recurrence

Wound contraction and macro-deformation during negative pressure therapy of sternotomy wounds

<p>Abstract</p> <p>Background</p> <p>Negative pressure wound therapy (NPWT) is believed to initiate granulation tissue formation via macro-deformation of the wound edge. However, only few studies have been performed to evaluate this hypothesis. The present study was performed to investigate the effects of NPWT on wound contraction and wound edge tissue deformation.</p> <p>Methods</p> <p>Six pigs underwent median sternotomy followed by magnetic resonance imaging in the transverse plane through the thorax and sternotomy wound during NPWT at 0, -75, -125 and -175 mmHg. The lateral width of the wound and anterior-posterior thickness of the wound edge was measured in the images.</p> <p>Results</p> <p>The sternotomy wound decreased in size following NPWT. The lateral width of the wound, at the level of the sternum bone, decreased from 39 ± 7 mm to 30 ± 6 mm at -125 mmHg (p = 0.0027). The greatest decrease in wound width occurred when switching from 0 to -75 mmHg. The level of negative pressure did not affect wound contraction (sternum bone: 32 ± 6 mm at -75 mmHg and 29 ± 6 mm at -175 mmHg, p = 0.0897). The decrease in lateral wound width during NPWT was greater in subcutaneous tissue (14 ± 2 mm) than in sternum bone (9 ± 2 mm), resulting in a ratio of 1.7 ± 0.3 (p = 0.0423), suggesting macro-deformation of the tissue. The anterior-posterior thicknesses of the soft tissue, at 0.5 and 2.5 cm laterally from the wound edge, were not affected by negative pressure.</p> <p>Conclusions</p> <p>NPWT contracts the wound and causes macro-deformation of the wound edge tissue. This shearing force in the tissue and at the wound-foam interface may be one of the mechanisms by which negative pressure delivery promotes granulation tissue formation and wound healing.</p

Penile intraepithelial neoplasia, penile cancer precursors and human papillomavirus prevalence in symptomatic preputium : a cross-sectional study of 351 circumcised men in Sweden

Objectives: To investigate the prevalence of pathological disease and spectrum of human papillomavirus (HPV) types among symptomatic foreskin tissue. Patients and Methods: Consecutively excised symptomatic foreskins from 351 men were sent for histopathological evaluation. During the surgical procedure, a fresh biopsy was taken for HPV analysis by modified general primer polymerase chain reaction. A medical questionnaire regarding medication, smoking habits, number of lifetime sexual partners, former diseases and surgery performed on penis was completed by all participants. Results: The most common clinical diagnosis and cause for circumcision was phimosis, seen in 85.2%. Histopathologically inflammatory dermatological conditions were present in 87% of the men. The most common histopathological diagnosis was lichen sclerosus (LS) observed among 58.7%. Notably, penile intraepithelial neoplasia (PeIN) was present in 2% without former clinical suspicion. Overall, HPV was detected in 17.1% of the men and 28 different HPV types were found. High-risk (HR) HPV types were identified in 9.1% and HPV16 was present in 2.3%. Current smoking increased the risk of HPV (crude odds ratio [OR] 2.8, confidence interval [CI] 1.4–5.6; P = 0.005). Having >15 lifetime sexual partners increased the risk of HPV (crude OR 2.6, 95% CI 1.4–5.1; P = 0.003) and when adjusted for current smoking the OR was substantially increased (OR 6.0, 95% CI CI 2.2–16.8; P < 0001). Conclusions: Histopathological evaluation of circumcised symptomatic foreskin revealed PeIN in 2% of the men without any clinical suspicion of malignancy and that treatable dermatological conditions were present in 87%, LS being the most common. HR-HPV types were present in 9%. Due to risk of malignant development both in PeIN and in inflammatory skin diseases we recommend sending all excised foreskins from patients with symptoms for histopathological evaluation as guidance for further clinical management

Incidence of penile intraepithelial neoplasia and treatment strategies in Sweden 2000–2019

Objectives: To analyse the incidence, treatment strategies and complications associated with penile intraepithelial neoplasia (PeIN) in Sweden over a period of 20 years. Materials and methods: Data on PeIN from the Swedish National Penile Cancer Register were analysed regarding treatment in relation to age, size of the PeIN lesion, localization of the PeIN lesion and complications using chi-squared tests and logistic regression. The incidence of PeIN was calculated and age-standardized according to the European Standard population. Results: Between 2000 and 2019 a total of 1113 PeIN cases were reported. The age-standardized incidence of PeIN was 1.40 per 100 000 men (95% confidence interval [CI] 1.32–1.49). An increase in incidence over time was seen, with a standardized incidence rate of 2.37 (95% CI 1.56–3.70) in 2019 compared to the baseline year, 2000. Surgical or topical treatments were given in 75.0% and 14.6% of cases, respectively. The complication rate was higher in laser surgery (12.1%, 7/58) compared to local surgery (4.6%, 16/348; P = 0.03) with an age-adjusted odds ratio (OR) of 2.82 (95% CI 1.10–7.19; P = 0.03). Local surgery was more common than laser surgery in the last 5 years compared to the first 5 years of the study period: OR 5.75 (95% CI 2.94–11.27). Treatments with imiquimod and topical 5-fluorouracil (5-FU) were more common than destructive methods such as photodynamic therapy, cryotherapy, curettage and electrocautery in the last 5 years compared to the first 5 years: OR 9.48 (95% CI 2.29–39.24). Conclusions: A twofold increase in the age-standardized incidence of PeIN was seen in Sweden over 20 years. Complications were three times more common in laser surgery compared to local surgery. Changes in treatment showed an increase of treatment strategies such as local surgery and treatment with imiquimod and topical 5-FU over time

Perfusion and Oxygenation of Random Advancement Skin Flaps Depend More on the Length and Thickness of the Flap Than on the Width to Length Ratio.

The aim was to investigate the relationship between the dimensions (length, width, and thickness) of random advancement skin flaps and retained tissue perfusion and oxygenation

Hypoperfusion in response to epinephrine in local anaesthetics : Investigation of dependence on epinephrine concentration, spread of hypoperfusion and time to maximal cutaneous vasoconstriction

Objectives: The present study aimed to examine hypoperfusion in response to epinephrine following the administration of a local anaesthetic. The . concentration of epinephrine that causes maximal hypoperfusion, the . spread of hypoperfusion in the tissue and the . time to the stabilization of hypoperfusion were investigated. Methods: Blood perfusion was monitored using laser Doppler velocimetry and laser speckle contrast imaging of random-pattern advancement flaps (1 × 4 cm) or intact skin on the pig flank. Epinephrine was either injected cumulatively (0.1, 1.0, 10 or 100 μg/ml) after injecting 20 mg/ml lidocaine, to determine the concentration response, or given as a single dose (12.5 μg/ml epinephrine. +. 20 mg/ml lidocaine). Control experiments were performed with saline or lidocaine (without epinephrine). Results: Increasing concentrations of epinephrine resulted in a gradual decrease in skin perfusion, approaching a minimum after injecting 10 μg/ml. The area of hypoperfusion was 12 mm in radius, and the time from the injection to the stabilization of hypoperfusion was approximately 120 s. After the administration of 10 μg/ml epinephrine in flaps with small pedicle, 25% blood perfusion still remained. Conclusions: Local anaesthetic with an epinephrine concentration of approximately 10 μg/ml appears to be adequate for vasoconstriction before surgery. Incisions were required to be delayed only for 2 min following local anaesthetic with epinephrine in pigs. The remaining 25% blood perfusion observed after the administration of epinephrine supports the use of epinephrine in flaps with a small pedicle. Obviously, these experimental findings must be clinically assessed before being considered for infiltration anaesthesia during plastic surgery procedures

Risk Factors for Penile Intraepithelial Neoplasia : A Population-based Register Study in Sweden, 2000-2012

Studies on risk factors for penile intraepithelial neo-plasia have been small in size, have not distinguished penile intraepithelial neoplasia from invasive cancer, and have relied on self-reported information. This study investigated risk factors for penile intraepithelial neoplasia in a cohort of 580 penile intraepithelial neoplasia cases and 3,436 controls using information from 7 Swedish registers. Cases with penile intraepithelial neoplasia had increased odds ratios (ORs) for inflammatory skin diseases (14.7, 95% CI 6.5-33.4) including lichen planus (12.0, 95% CI 3.0-48.0), indicating lichen planus to be an important risk factor. Increased ORs were also observed for diseases of the prepuce (4.0, 95% CI 2.2-7.4), immunosuppressive drugs (5.0, 95% CI 2.5-9.8), penile surgical procedures (4.8, 95% CI 2.2-10.8), balanitis (9.2, 95% CI 5.0-16.8), genital warts (9.9, 95% CI 4.3-22.7) and organ transplantation (7.0, 95% CI 2.4-20.8). This study demonstrates important risk factors for penile intraepithelial neoplasia, providing knowledge that can help prevent the development of penile cancer