1512 A Service Evaluation of Transoral Laser Resection Procedures for Oral Cancer and Dysplasia

Aim

The use of the diode laser is a frequently employed treatment modality in primary surgical excision, especially for early oral cancer. This is due to advantages offered in precision of excision, and potential reduced post-operative pain compared to other excision methods. Additionally, haemostasis can often be obtained simultaneous to excision. Despite frequent use of laser excision for oral cancer/dysplasia, there is limited information on the incidence of postoperative complications.

Method

Data was collected retrospectively by review of electronic healthcare records for a 5-year period (Jan 2015-Jan 2020) for patients who underwent transoral laser excision of oral dysplasia in a major UK teaching hospital. The number of short (<30 days) and longer-term complications was evaluated and categorised using the Clavien-Dindo classification.

Results

A total 260 patients received diode laser resection for oral cancer/dysplasia in this period. Approximately one third of patients had the diagnosis of SCC and 52% of patients were treated on a day case basis. Approximately one third of patients experienced postoperative complications.; including positive or close resection margins (16%), bleeding (8%), superficial infection (6%) and significant postoperative pain (2%). A total of 16% of patients required further treatment in theatre (Clavien-Dindo IIIb).

Conclusions

The use of lasers for excision of oral tumours and dysplastic lesions is a frequently employed modality, offering advantages to the operating surgeon (improved haemostasis, excellent manoeuvrability) and patients (reduced pain and scarring). Complications are largely predictable in nature, but the surgical team should be aware of potential issues to ensure safe, effective patient care.

Case Report of Sarcoidosis as a Great Mimicker in Various Populations

INTRODUCTION

The prevalence of sarcoidosis varies as much as 1-40 cases per 100,000 depending on region and population. Sarcoid typically occurs in people younger than 50 years old, with a peak incidence with ages between 20 and 40 years old. African Americans are 3 times more likely to develop sarcoidosis than Caucasian Americans, and woman are more likely than men to develop sarcoidosis in any ethnic group; nonetheless, it remains a valid differential across any population.

CASE

A 32 year old Hispanic man presented to the Emergency Department with night sweats, fatigue, and 35 pound unintentional weight loss over the last several weeks. He also reported a sore throat, occasional cough w/ yellowish sputum, and new onset dyspnea with exertion. He moved from Mexico to the U.S. 20 years prior and last visited the country 7 yrs ago. He never smoked and denied any TB exposure. His vitals at admit demonstrated tachycardia (pulse 108); and temperature of 99.4 ᴼF. He had coarse bilateral breath sounds on exam. Serum chemistries were unremarkable. Chest radiograph demonstrated perihilar fullness. Chest CT revealed enlarged mediastinal and perihilar LAD and airspace consolidation in right middle and lower lobes bilaterally. The patient was admitted to a negative pressure room w/ airborne precautions and RIPE therapy was initiated. PPD and AFB's were negative. He underwent bronchoscopy and was discharged on RIPE. Lung biopsy showed non-caseating granulomas. RIPE therapy was stopped, and he was referred to ophthalmology to rule out uveitis. Cultures from the procedure were negative for fungal growth, and he was started on prednisone 40 mg daily with taper 6 weeks later as his weight returned, night sweats subsided, and dyspnea on exertion improved.

DISCUSSION

Sarcoidosis should be considered as a diagnosis in any gender of any racial or ethnic group. Sarcoid is a great mimicker of many serious illnesses including malignancies such as lymphomas, TB and atypical mycoplasma, fungal infections, and other granulomatous diseases, and other autoimmune disorders such a hypersensitivity pneumonitis. Diagnosis requires patient investigation and careful analysis of these differentials.

Systems-based practice in graduate medical education: systems thinking as the missing foundational construct

BACKGROUND

Since 2001, residencies have struggled with teaching and assessing systems-based practice (SBP). One major obstacle may be that the competency alone is not sufficient to support assessment. We believe the foundational construct underlying SBP is systems thinking, absent from the current Accreditation Council for Graduate Medical Education competency language.

SUMMARY

Systems thinking is defined as the ability to analyze systems as a whole. The purpose of this article is to describe psychometric issues that constrain assessment of SBP and elucidate the role of systems thinking in teaching and assessing SBP.

CONCLUSION

Residency programs should incorporate systems thinking models into their curricula. Trainees should be taught to understand systems at an abstract level, in order to analyze their own healthcare systems, and participate in quality and patient safety activities. We suggest that a developmental trajectory for systems thinking be developed, similar to the model described by Dreyfus and Dreyfus.

Rapsyn mutations in myasthenic syndrome due to impaired receptor clustering

Rapsyn, a 43-kDa postsynaptic protein, is essential for anchoring and clustering acetylcholine receptors (AChRs) at the endplate (EP). Mutations in the rapsyn gene have been found to cause a postsynaptic congenital myasthenic syndrome (CMS). We detected six patients with CMS due to mutations in the rapsyn gene (RAPSN). In vitro studies performed in the anconeus muscle biopsies of four patients showed severe reduction of miniature EP potential amplitudes. Electron microscopy revealed various degrees of impaired development of postsynaptic membrane folds. All patients carried the N88K mutation. Three patients were homozygous for N88K and had less severe phenotypes and milder histopathologic abnormalities than the three patients who were heterozygous and carried a second mutation (either L14P, 46insC, or Y269X). Surprisingly, two N88K homozygous patients had one asymptomatic relative each who carried the same genotype, suggesting that additional genetic factors to RAPSN mutations are required for disease expression.

Choline acetyltransferase mutations in myasthenic syndrome due to deficient acetylcholine resynthesis

The myasthenic syndrome due to abnormal acetylcholine resynthesis is characterized by early onset, recessive inheritance, and recurrent episodes of potentially fatal apnea. Mutations in the gene encoding choline acetyltransferase (CHAT) have been found to account for this condition. We have identified five patients from three independent families with features of this disease including, in four patients, a paradoxical worsening of symptoms with cold temperatures. Electrodiagnostic studies demonstrated impaired neuromuscular transmission in all patients. In vitro microelectrode studies performed in the anconeus muscle biopsies of two patients showed moderate reduction of quantal release. Electron microscopy of the neuromuscular junction was normal in both patients. Each patient had two heterozygous CHAT mutations including L210P and P211A (family 1), V194L and V506L (family 2), and R548stop and S694C (family 3). Three of these mutations have previously been reported and suggest that, in this syndrome, some molecular defects may be more prevalent than others.

D-2-hydroxyglutaric aciduria

Hydroxyglutaric aciduria is detected by gas chromatographic-mass spectrometric analysis, and the D and L forms are quantified by chemical ionization with deuterated internal standards. Patients have recently been described who accumulate the D form, and they appear to be quite different from those with the more common L form. Experience is reported with three patients and an animal model with D-2-hydroxyglutaric aciduria. The phenotype appears to include mental retardation, macrocephaly, hypotonia, seizures, and involuntary movements, although neurologic and systemic manifestations of the disorder varied considerably between individual patients, even within the same family.

Nodal spacing along regenerated axons following a crush lesion of the developing rat sciatic nerve

The relation between internodal length (L) and fibre diameter (D) was examined light microscopically in teased specimens from normal developing rat sciatic nerves, and from rat sciatic nerves which had regenerated following crush lesions at various postnatal ages. In newborn rat pups virtually all sciatic nerve axons are unmyelinated and myelination is an essentially postnatal event. Between 2 weeks and 6 months maximal L increases from 500 microns to 1400 microns and maximal D increases from 6-8 microns to 16 microns. The increase in L matches the length growth of the hindlimb. Signs of myelin sheath remodelling are absent during normal development. Examination of regenerated nerves showed that the lengths of the internodes along large-medium-sized axons, are strongly dependent on crush age. In neonatally crushed nerves, the slope is close to normal. With increasing crush age the inclination of the regression line gradually decreases. Signs of myelin sheath remodelling are not seen in regenerated nerves crushed at birth or 1-2 weeks after birth. However, such signs are present in regenerated nerves crushed 3 weeks or more after birth. These observations support the view that myelin sheath remodelling in regenerated rat sciatic nerves is directly related to a deficient length growth following myelination.

Calcium blocking properties of piprofurol

Piprofurol is a benzofuran chalcon derivative. It was studied under various experimental conditions which allow the recognition of calcium antagonistic activity. Piprofurol inhibited in a concentration-dependent manner the calcium-induced contractions in isolated potassium depolarized preparations of rat aorta (pA2: 9.29) and relaxed the K+-induced contraction of the dog coronary artery and the rabbit basilar artery (IC's 50: 2 10(-8) M; 3 10(-9) M). Piprofurol also inhibited noradrenaline-induced vascular smooth muscle contractions but the antagonism was clearly noncompetitive and the contractions induced were altered by concentrations two orders of magnitude higher than the concentration inhibiting calcium-induced contractions. Calcium antagonism was demonstrated in cardiac muscle: calcium mediated slowly rising action potentials were evoked in partially depolarized guinea-pig papillary muscle by electrical stimulation in the presence of isoprenaline. Piprofurol decreased the rate of rise of these slow action potentials. The inhibitory effect was reversed by an elevation of the calcium concentration in the bath fluid. Piprofurol exerts a negative inotropic effect (IC50: 5 10(-6) M) on guinea-pig papillary muscle. The ratio IC50 inotropic action/IC50 relaxant activity was 230, i.e. higher than that obtained with verapamil or diltiazem, and near that observed for cinnarizine. The pharmacological profile from in vivo dog experiments is in agreement with its in vitro properties: coronary sinus blood flow was increased and heart rate decreased. These effects suggested a potentially anti-ischaemic activity. This is confirmed in anaesthetized dogs, where piprofurol reduced the epicardial ST-segment elevation following coronary artery occlusion, and in isolated heart preparations, where it decreased the leakage of LDH during periods of anoxia and reoxygenation.

Lipid intermediates in chronically volume-overloaded rat hearts. Effect of diffuse ischemia

Tissue contents of intermediates of fatty acid metabolism were determined in isolated volume-overloaded rat hearts, 3 months after creation of an aorto-caval fistula. In the absence of any modification of blood carnitine, tissue levels of total carnitine were reduced by 33% in overloaded hearts compared to normal hearts. Total tissue CoA was unchanged. Fifteen minutes of whole-heart ischemia (i.e. a 50% reduction in coronary flow) did not increase levels of long-chain acyl esters of CoA and carnitine of the overloaded myocardium, in the presence of glucose as the only exogenous substrate. This was associated with lower than normal levels of long-chain acyl carnitine under normoxic conditions. The addition of exogenous palmitate (1.5 mM) resulted in an ischemia-induced accumulation of long-chain acyl-CoA and acyl carnitine in the overloaded heart although to a smaller extent than in the normal heart under similar perfusion conditions.