Major modifications to minimize thoracic esophago-gastric leak and eradicate esophageal stricture after Ivor Lewis esophagectomy

BACKGROUND

The Ivor Lewis esophagectomy (ILE) remains the procedure of choice for localized middle or lower esophageal carcinoma. Nevertheless, anastomotic leak remains a common complication with rates from 3% to 25% and a stricture rate as high as 40%. The frequency of these complications suggests that the procedure itself may have inherent limitations including the use of potentially ischemic tissue for the esophagogastric anastomosis. We introduce a modified technique that reduces operative steps, preserves blood supply, and uses a modified esophagogastric anastomosis.

METHODS

All consecutive patients undergoing ILE with the described modified technique were identified. An esophagram was performed on postoperative day six or seven. To ensure that all cases were identified, anastomotic leaks were defined as any radiographic evidence of contrast extravasation.

RESULTS

A total of 110 patients underwent the modified esophagectomy with 2 anastomotic leaks (1.82%) and zero strictures. There was 1 late death but no early deaths (<30 or 90 days) or early re-admissions (<30 days). The average number of risk factors was 2.12, and 98 patients (90%) had at least 1 risk factor in their medical history.

CONCLUSIONS

The modifications proposed simplify procedural steps, limit unnecessary dissection and introduce a technique that ends the practice of connecting ischemic tissue. We believe this technique contributes to surgical durability and reduces the rate of postoperative leak and eliminates stricture.

In the peripheral blood mononuclear cells (PBMCs) of HCV infected patients the expression of STAT1 and IRF-1 is downregulated while that of caspase-3 upregulated

Several peripheral blood mononuclear cell (PBMC) defects have been linked with hepatitis C virus (HCV) infection, including alterations in cytokine secretion and increased cell death. This study was performed to investigate the expression levels of signal transducer and activator of transcription 1 (STAT1), interferon regulatory factor 1 (IRF-1), and caspase 3 in PBMCs of patients infected with HCV. STAT1, IRF-1, and caspase 3 expression levels were compared in PBMCs from 19 untreated (naïve) HCV+ patients, 8 treated (sustained responder [SR]) HCV patients, and 20 HCV- healthy controls. Moreover, PBMCs from naïve HCV+ patients and SR-HCV patients were also evaluated for HCV RNA expression. The expression levels of STAT-1 and IRF-1 were significantly downregulated in PBMCs from naïve HCV+ patients (P  Keywords: PBMC; hepatitis C virus; STAT1; IRF-1; caspase-3.

COVID-19 ventilator barotrauma management: less is more

Background

COVID-19 patients requiring mechanical ventilation may develop significant pneumomediastinum and sub-cutaneous emphysema without associated pneumothorax (SWAP). Prophylactic chest tube placement or sub-fascial "blowholes" are usually recommended to prevent tension pneumothorax and clinical decline. Risk of iatrogenic lung injury and release of virus into the environment is high. Incidence and conservative management data of such barotraumatic complications during the COVID-19 pandemic are lacking.

Methods

All patients with mediastinal air and SWAP evaluated by the department of Thoracic Surgery at the Mount Sinai Hospital between March 30 and April 10, 2020 were identified. All patients without pneumothorax were treated conservatively with daily chest x-ray and observation. Three patients had prophylactic chest tube placement prior to the study period without thoracic surgery consultation.

Results

There were 29 cases of mediastinal air with SWAP out of 171 COVID positive intubated patients (17.0%) who were treated conservatively. Patients were intubated for an average of 2.4 days before SWAP was identified. 12 patients (41%) had improvement or resolution without intervention. Two patients progressed to pneumothorax 3 and 8 days following initial presentation. Both had chest tubes placed without incident before there were any changes in oxygenation, hemodynamics, supportive medications, or ventilator settings. There were 3 patients who had percutaneous tubes placed before the study period all of whom had significant worsening of their sub-cutaneous air and air leak.

Conclusions

Conservative management of massive sub-cutaneous emphysema without pneumothorax in COVID-19 patients is safe and limits viral exposure to healthcare workers. Placement of chest tubes is discouraged unless a definite sizable pneumothorax develops.

Measuring the Kerr nonlinearity via seeded Kerr instability amplification: conceptual analysis

Whereas the Kerr nonlinearity is well understood in the perturbative limit of nonlinear optics, there is considerable discussion about its functional form and magnitude at extreme intensities, at which point matter starts to ionize. Here, we introduce a concept to answer this question and theoretically analyze its feasibility. We demonstrate that seeded Kerr instability amplification provides clear signatures from which functional form and magnitude of the Kerr nonlinearity can be extracted in the non-perturbative limit of nonlinear optics.

Greenhouse gas and ammonia emissions from production of compost bedding on a dairy farm

Recent developments in composting technology enable dairy farms to produce their own bedding from composted manure. This management practice alters the fate of carbon and nitrogen; however, there is little data available documenting how gaseous emissions are impacted. This study measured in-situ emissions of methane (CH₄), carbon dioxide (CO₂), nitrous oxide (N₂O), and ammonia (NH₃) from an on-farm solid-liquid separation system followed by continuously-turned plug-flow composting over three seasons. Emissions were measured separately from the continuously-turned compost phase, and the compost-storage phase prior to the compost being used for cattle bedding. Active composting had low emissions of N₂O and CH₄ with most carbon being emitted as CO₂-C and most N emitted as NH₃-N. Compost storage had higher CH₄ and N₂O emissions than the active phase, while NH₃ was emitted at a lower rate, and CO₂ was similar. Overall, combining both the active composting and storage phases, the mean total emissions were 3.9×10^-2gCH₄kg^-1 raw manure (RM), 11.3gCO₂kg^-1 RM, 2.5×10^-4g N₂O kg^-1 RM, and 0.13g NH₃ kg^-1 RM. Emissions with solid-separation and composting were compared to calculated emissions for a traditional (unseparated) liquid manure storage tank. The total greenhouse gas emissions (CH₄+N₂O) from solid separation, composting, compost storage, and separated liquid storage were reduced substantially on a CO₂-equivalent basis compared to traditional liquid storage. Solid-liquid separation and well-managed composting could mitigate overall greenhouse gas emissions; however, an environmental trade off was that NH₃ was emitted at higher rates from the continuously turned composter than reported values for traditional storage.

Unruptured congenital aneurysm of the left sinus of Valsalva in an adult with complex left heart malformations

A 26 year old man who presented with the first signs of right heart failure was found to have a large congenital aneurysm of the aortic sinus of Valsalva and of the left coronary sinus. These were combined with left heart anomalies in the form of a bicuspid aortic valve, a rare variant of a persistent left superior vena cava with blood flow from the left atrium through the brachiocephalic vein into the superior vena cava and a kink in the aortic arch. An aortic coarctation had been corrected with a patch 12 years earlier. Although the aneurysm was not perforated and there were no clinical signs of infarction, the aneurysm was resected prophylactically and the left coronary artery was reinserted through a bypass with a Gore-Tex conduit. The case is noteworthy because this diagnosis is very rare and its early treatment may prevent several complications. The clinical features, treatment, and outcome are discussed.

Dietary fish oil reduces microvascular thrombosis in a porcine experimental model

Microvascular thrombosis plays a significant role in the pathophysiology of ischaemic reperfusion injury. A fish oil-supplemented diet containing n-3 polyunsaturated fatty acids (PUFA) reduces thromboxane A(2) (TxA(2)) synthesis and, thus, vasoconstriction and platelet aggregation. The aim of this study was to elucidate whether n-3 PUFA in a porcine model of ischaemia and reperfusion injury 1) inhibit accumulation of platelets and fibrinogen in ischaemia-reperfusion injured tissue, 2) prolong the bleeding time, and 3) inhibit TxA(2) synthesis. Nine pigs were fed a standard diet supplemented with 7 g n-3 PUFA/day for 3 weeks. Nine pigs on the standard diet served as controls. Unilateral myocutaneous flaps were exposed to ischaemia for a period of 6 hours. Contralateral flaps were nonischaemic. Tissue contents of radioactive-labelled platelets and fibrinogen were measured after 4 hours of reperfusion. Platelet count, serum TxB(2), and the cutaneous bleeding time were measured before and after 3 weeks of diet. In the fish oil group, the accumulation of platelets was significantly reduced in all the myocutaneous flaps, except in the ischaemic skin part, when compared to control animals. Fibrinogen was significantly reduced in nonischaemic flaps, but not in ischaemic flaps. After the feeding period, the level of TxB(2) was significantly lowered in the fish oil group (p<0.01). No difference in the bleeding time was observed. Thus, dietary supplementation with n-3 PUFA inhibits the formation of microvasculatory thrombosis in this model.

Evaluation of stimulation parameters on aortomyoplasty, using Latissimus Dorsi muscle in a goat model: an acute study

OBJECTIVE

Dynamic aortomyoplasty using Latissimus Dorsi muscle (LDM) has been shown to improve myocardial function. However, systematic examination of the effects of stimulation parameters on aortic wrap function has not been done. Thus, the present study measures the direct effect of stimulation voltage, pulse train duration, frequency of the pulses, and the duration of the stimulation delay from R wave on the aortic wrap function.

METHODS

In eight female goats, the left LDM was wrapped around the descending aorta. The muscle was then subjected to electrical stimulation, altering frequency of stimulation pulses (16.6, 20, 25, 33 and 50 Hz), amplitude (2, 4, 6, 8 and 10 V), and number of pulses (2, 4, 6, 8 and 10 pulses) in a train stimulation. Left ventricular, aortic pressure, and pressure generated by LDM on aorta (wrap pressure) was measured. The changes in hemodynamic parameters mentioned above were calculated and compared for different stimulation parameters during unassisted and assisted cardiac cycles.

RESULTS

Aortomyoplasty counterpulsation using LDM provided significant improvement in wrap pressure (78 mmHg +/- 2), aortic diastolic pressure, and changes in aortic diastolic pressure from 2 to 4 V (P < 0.05). Further increase in amplitude did not make any significant improvements of the above mentioned parameters. Significant augmentation of wrap pressure (82 mmHg +/- 2), aortic diastolic pressure (79 mmHg +/- 3) and changes in aortic diastolic pressure (12 mmHg +/- 1) occurred at 6 pulses (P < 0.05). Other changes in number of pulses did not show any significant improvements. Significant improvement of wrap pressure (80 mmHg +/- 2), aortic diastolic pressure (73 mmHg +/- 3) and changes in aortic diastolic pressure (12 mmHg +/- 1) was observed with a frequency of 33 Hz. To examine a wide range of delays from the onset of the QRS complex to LDM stimulation, stimulation was delivered randomly. The exact delay was determined from the ECG signal and superimposed LDM stimulation pulses.

CONCLUSIONS

In this study we present a new measurement, wrap pressure. We also present that in aortomyoplasty using LDM, the most significant improvement in wrap pressure, aortic diastolic pressure and changes in aortic diastolic pressure occurs when the stimulation consists of an amplitude of 4 V, a frequency of 33 Hz and a train stimulation of 6 pulses.