Acute Cardiovascular and Sympathetic Effects of Nicotine Replacement Therapy

Sympathetic overactivity is implicated in the increased cardiovascular risk of cigarette smokers. Excitatory nicotinic receptors are present on peripheral chemoreceptor cells. Chemoreceptors located in the carotid and aortic bodies increase ventilation (Ve), blood pressure (BP), heart rate (HR), and sympathetic nerve activity to muscle circulation (MSNA) in response to hypoxia. We tested the hypothesis that nicotine replacement therapy (NRT) increases MSNA and chemoreceptor sensitivity to hypoxia. Sixteen young healthy smokers were included in the study (8 women). After a randomized and blinded sublingual administration of a 4-mg tablet of nicotine or placebo, we measured minute Ve, HR, mean BP, and MSNA during normoxia and 5 minutes of isocapnic hypoxia. Maximal voluntary end-expiratory apneas were performed at baseline and at the end of the fifth minute of hypoxia. Nicotine increased HR by 7±3 bpm, mean BP by 5±2 mm Hg, and MSNA by 4±1 bursts/min, whereas subjects breathed room air (all P <0.05). During hypoxia, nicotine also raised HR by 8±2 bpm, mean BP by 2±1 mm Hg, and MSNA by 7±2 bursts/min (all P <0.05). Nicotine increased MSNA during the apneas performed in normoxia and hypoxia ( P <0.05). Nicotine also raised the product of systolic BP and HR, a marker of cardiac oxygen consumption, during normoxia, hypoxia, and the apneas ( P <0.05). Ve, apnea duration, and O 2 saturation during hypoxia and the apneas remained unaffected. In conclusion, sympathoexcitatory effects of NRT are not because of an increased chemoreflex sensitivity to hypoxia. NRT increases myocardial oxygen consumption in periods of reduced oxygen availability.

Increased Peripheral Chemoreceptors Sensitivity and Exercise Ventilation in Heart Transplant Recipients

BACKGROUND

Heart failure is characterized by increased ventilation during exercise, which is positively related to increased peripheral and central chemoreceptor sensitivity. Heart transplantation does not normalize the ventilatory response to exercise, and its effects on the chemoreflex control of ventilation remain unknown. We tested the hypothesis that chemoreceptor sensitivity is increased in heart transplant recipients (HTRs) and linked to exercise hyperpnea.

METHODS AND RESULTS

We determined the ventilatory, muscle sympathetic nerve activity (MSNA), and circulatory responses to isocapnic hypoxia and hyperoxic hypercapnia 7+/-1 years after transplantation in 19 HTRs with a normal left ventricular ejection fraction of 60+/-2%. Results were compared with those of 11 closely matched referent subjects. Sixteen patients and 10 referent subjects also underwent cycle ergometer exercise tests. HTRs compared with referent subjects presented higher MSNA (52+/-4 versus 34+/-3 bursts/min; P<0.01) and heart rates (83+/-3 versus 68+/-3 bpm; P<0.01) during room air breathing. The ventilatory response to hypoxia was higher in HTRs than in referent subjects (P<0.01, ANOVA). The increase in MSNA also was more marked during hypoxia in the HTRs than in the referent group (P<0.05, ANOVA). Responses to hyperoxic hypercapnia did not differ between the HTRs and the referent group. The ventilatory response to exercise, characterized by the regression slope relating minute ventilation to CO2 output, was steeper in HTRs than in referent subjects (38+/-2 versus 29+/-1 L/mm Hg; P<0.01). Exercise ventilation in HTRs was related to the ventilatory response to isocapnic hypoxia (r=0.57; n=16; P<0.05) and to the ventilatory response to hyperoxic hypercapnia (r=0.50; n=16; P<0.05).

CONCLUSIONS

Peripheral chemoreceptor sensitivity is increased in HTRs and is related to exercise hyperpnea after heart transplantation.

Hyperoxia enhances metaboreflex sensitivity during static exercise in humans

Peripheral chemoreflex inhibition with hyperoxia decreases sympathetic nerve traffic to muscle circulation [muscle sympathetic nerve activity (MSNA)]. Hyperoxia also decreases lactate production during exercise. However, hyperoxia markedly increases the activation of sensory endings in skeletal muscle in animal studies. We tested the hypothesis that hyperoxia increases the MSNA and mean blood pressure (MBP) responses to isometric exercise. The effects of breathing 21% and 100% oxygen at rest and during isometric handgrip at 30% of maximal voluntary contraction on MSNA, heart rate (HR), MBP, blood lactate (BL), and arterial O2 saturation (SaO2) were determined in 12 healthy men. The isometric handgrips were followed by 3 min of postexercise circulatory arrest (PE-CA) to allow metaboreflex activation in the absence of other reflex mechanisms. Hyperoxia lowered resting MSNA, HR, MBP, and BL but increased Sa(O2) compared with normoxia (all P < 0.05). MSNA and MBP increased more when exercise was performed in hyperoxia than in normoxia (MSNA: hyperoxic exercise, 255 +/- 100% vs. normoxic exercise, 211 +/- 80%, P = 0.04; and MBP: hyperoxic exercise, 33 +/- 9 mmHg vs. normoxic exercise, 26 +/- 10 mmHg, P = 0.03). During PE-CA, MSNA and MBP remained elevated (both P < 0.05) and to a larger extent during hyperoxia than normoxia (P < 0.05). Hyperoxia enhances the sympathetic and blood pressure (BP) reactivity to metaboreflex activation. This is due to an increase in metaboreflex sensitivity by hyperoxia that overrules the sympathoinhibitory and BP lowering effects of chemoreflex inhibition. This occurs despite a reduced lactic acid production.

Effects of Peripheral Chemoreceptors Deactivation on Sympathetic Activity in Heart Transplant Recipients

Heart transplantation initially normalizes sympathetic hyperactivity directed at the muscle circulation. However, sympathetic activity increases with time after transplantation and the exact mechanisms responsible for sympathetic control in heart transplant recipients remain unclear. We examined the effects of peripheral chemoreflex deactivation caused by breathing 100% oxygen on muscle sympathetic nerve activity (expressed as number of burst per minute and mean burst amplitude), heart rate, and mean blood pressure in 13 heart transplant recipients, 13 patients with essential hypertension, and 10 controls. Heart transplant recipients disclosed the highest sympathetic activity, whereas it did not differ between controls and patients with essential hypertension (51+/-16 versus 37+/-14 versus 39+/-12 burst/min, respectively; P<0.05). Breathing 100% oxygen, in comparison with 21% oxygen, reduced sympathetic activity (-4+/-4 versus -1+/-2 burst/min, P<0.01; 85+/-9 versus 101+/-8% of amplitude at baseline, P<0.001) and mean blood pressure (-4+/-5 versus +3+/-6 mm Hg; P<0.05) in heart transplant recipients, decreased sympathetic activity (-4+/-4 versus 0+/-3 burst/min, P<0.05; 90+/-16 versus 101+/-9% of amplitude at baseline, P<0.05) in patients with essential hypertension, but did not reduce sympathetic activity (2+/-4 versus 3+/-3 burst/min, P=NS; 95+/-11 versus 95+/-13% of amplitude at baseline, P=NS) in control subjects. The sympathetic response to hyperoxia was more marked in heart transplant recipients than in controls (85+/-9 versus 95+/-11% of baseline amplitude; P<0.05). The decrease in sympathetic activity was most evident in patients with the longest time after heart transplantation (r=-0.75, P<0.01). In conclusion, tonic chemoreflex activation increases resting muscle sympathetic nerve activity and favors blood pressure elevation after heart transplantation.

From Open to Robotic-assisted Latissimus Dorsi Muscle Flap Harvest

Background:

The latissimus dorsi muscle is the largest muscle in the body. The classic open flap harvest technique of this muscle results in a long posterolateral thoracic vertical oblique incision that can leave an unappealing scar. The minimally invasive robotic approach has the potential to reduce scar length and to overcome technical limitations of endoscopic techniques.

Methods:

Six robotically assisted latissimus dorsi muscle flaps were harvested by a single surgeon. One was used as reversed turnover pedicled flap based on lumbar perforators for lumbosacral bone coverage, another flap was transposed for a Poland syndrome anterior axillary line reconstruction, and the remaining 4 were dissected as free flaps for upper and lower limb reconstruction. All 6 procedures used a short 5-cm axillary crease incision along the posterior axillary fold and two 8-mm port incisions for robotic access.

Results:

The first robotic flap harvest was converted to the classic open technique due to malposition of the 2 lower port incisions too close to the latissimus dorsi anterior border. The 5 other flaps were successfully transferred without flap or donor site complications. The average flap dissection time was 110 minutes; latter surgeries took less time than the early surgeries as the surgeon became more familiar with the robotic system and due to the use of a newer system.

Conclusion:

Robotic-assisted latissimus dorsi muscle flap harvest is a safe, reproducible, and effective tool that offers precise dissection control and that leaves a minimal thoracic scar.

Advanced cutaneous squamous cell carcinoma of the head in two renal transplanted patients treated with cemiplimab

It is well known that organ transplant recipients are prone to develop non-melanoma skin cancers, particularly cutaneous squamous cell carcinoma (cSCC). This is explained by the long-term use of immunosuppressants and thus the decrease of the immunosurveillance that protects from developing malignant tumours. Solid organ transplant recipients (SOTRs) are 65-250 times more likely to develop cSCC compared to the general population (Am J Transplant 2017; 17: 2509). Moreover, in these patients cSCCs follow a more aggressive course. Close follow-up and regular skin check-ups by a dermatologist are, therefore, crucial in the management of these patients. When detected early, cSCC can be easily and effectively treated by a simple excision. However, when advanced, outcomes are poor. Immune checkpoints inhibitors (ICIs) have been recently added to our arsenal and represent a breakthrough, having proved to be effective in achieving long-term responses. We, hereby, present two cases of difficult-to-treat cSCCs in renal transplanted patients.

Case 247: Jersey Finger of the Fifth Finger

History A 34-year-old man without underlying medical conditions came to the emergency department for evaluation of persistent pain over the volar portion of his right fifth finger after a fall during a football match 3 days before. At physical examination, the injured finger was swollen and purple. Passive and active flexion of the proximal and distal interphalangeal joints were compromised, without interphalangeal instability. Radiography was performed in the emergency department, and the patient was released with a diagnosis of a fifth digit sprain. After the senior radiologist (V.M.C.) reviewed the radiographs, the patient was called back for assessment with ultrasonography (US) on the same day. US was performed with an Aplio 500 unit (Toshiba Medical Systems, Tokyo, Japan) using a multifrequency linear array 7.2-18.0-MHz PLT-1204BX transducer focused at the level of the flexor tendon. The patient was sitting in front of the examiner, with the hand lying palm up on the examination bed. No abnormality was observed during color Doppler US.

Lymphatic Alterations Under Tattoos: Preliminary Reports of One Observational Study

Background

The number of people within the European population having at least one tattoo has increased notably and with it the number of tattoo-associated clinical complications. The injected inks are known to be removed by the lymphatic vessels and can be found in the draining lymph nodes.

Aim of the Study

To report our observations on the lymphatic drainages seen under tattoos using near infrared fluorescence imaging of these lymphatic vessels after the injection of indocyanine green.

Material and Methods

Indocyanine green was injected intradermally at the basis of the 20 tattooed area(s) in 19 subjects (nine women and ten men; mean age = 28.6). Ten subjects had only black tattoos (six upper limbs and four lower limbs), five (two upper limbs and three lower limbs) black and white tattoos and five multi-colored tattooed limbs (four lower limbs and one upper limb).

Results

The imaging exams revealed alterations in eight individuals, seven of whom had tattoos on their lower limbs. Furthermore, the imaging results showed that the abnormalities might be related to the tattooed limb, the tattoo extent and colour.

Conclusion

Alterations of the cutaneous lymphatic channels are frequently observed under tattooed territories. Their causal factors should be more precisely studied in future works and these lymphatic alterations should be considered in tattooed patients when using similar imaging techniques for therapeutic and surgical assessments.

[Acute and latent right side diaphragmatic rupture after blunt trauma: cases studies and review of the literature]

A right diaphragmatic rupture (RDR) after blunt trauma is rare. Diagnosis of this entity remains difficult due to the absence of a precise anamnesis and pathognomonic signs. We report two cases of acute and latent RDR respectively. Immediate laparotomy was performed in the first case and thoracotomy was done nine weeks after blunt trauma for the second one. After the hepatothorax reduction, diaphragmatic lesions were sutured and reinforced by prosthesis. Acute RDR evolve inevitably to a latent and obstructive phases. Then, the mainstay treatment is surgical repair of the diaphragmatic defect. At present, thoracotomy is recommended for latent RDR. In the acute phases, thoracic and/or abdominal approaches depend on associated lesions, hemodynamical patient stability and surgical competence of the practitioner.

[News in the treatment of Dupuytren's disease: from surgery to collagenase's injection]

Dupuytren's disease is a benign fibromatosis affecting the palmar and digital fascia and causing flexion contracture of the affected fingers. Up to date, this affection has no curative treatment available. The author is presenting an updated review of the therapeutic arsenal available for Dupuytren's disease cords correction. Open fasciectomy remains the "gold standard" surgical treatment of the disease but enzymatic treatment of the cords by injected collagenase clostridium histolyticum represents a promising new therapeutic. Recent published data are showing that this procedure gives comparable results to the published ones for segmental fasciectomy in terms of cords correction and recurrence prevention but with the advantage of a quicker recovery with a minimal morbidity.

Primary trapeziectomy with Regjoint(TM), a poly-L/D-lactide spacer, a two-year follow-up study with new radiological assessment tool

The aim of this retrospective study was to evaluate the potential bony erosion and the clinical and radiological results of primary trapeziectomy with RegjointTM interposition, in patients with peritrapezial arthritis. Data were recorded on twenty patients over a period of two years (January 2015-December 2016). On average 24 months, patients were reconvened for a post-operative evaluation (subjective evaluation of pain, function and patient satisfaction; clinical evaluation with strength and mobility measures; post-operative X-rays). On X-rays, 2 criteria were evaluated: the bony erosion and the shortening of the thumb column (trapezium+metacarpal height measure, ratio between first and second metacarpal bones, a new radiological assessment tool based on a trapezoid relationship gradation). In most patients, surgery relieved pain and offered good functional results, according to the Quick Disabilities of the Arm, Shoulder and Hand scale. Following surgery, our patients showed a subjective improvement, both in terms of pain and functional results. For plain X-ray, only 3 patients showed an osteolytic lesion (maximum of 2.8 millimeters) on the first metacarpal base. A statistically significant reduction in the thumb column height was generally observed on follow-up X-rays. However, all of these radiologic changes were present without any clinical impact. We show that the RegjointTM spacer is an available alternative in the surgical treatment of peritrapezial arthritis. We did not highlight any significant associated complications, no important adverse tissue reaction or bone erosion, no pain or functional disorder. Type of study/level of evidence Therapeutic IV.