Comparison between computerized tomography-guided bronchial width measurement versus conventional method for selection of adequate double lumen tube size

Background: Selection of adequate size double lumen tube (DLT) is complicated by marked inter-individual variability in morphology and dimensions of tracheobronchial tree. Computerized tomography (CT)-guided left bronchus width measurement has been used to predict adequate size DLT in European and Singapore population; however, no such data exist for Indian population who are racially different. We compared the effect of DLT size selection based on CT-guided bronchial width measurement to the conventional method of DLT selection on the adequacy of both lungs isolation and on the safety margin of right-sided DLT. Methods: Fifty-five adults scheduled to undergo thoracotomy were enrolled in this prospective observational study. An appropriate size left- or right-sided DLT with outer diameter 0.5–1 mm smaller than the CT-measured bronchial width was selected for the isolation of lungs. Adequacy of separation was checked using fiberoptic bronchoscope. The safety margin of selected right-sided DLT size was calculated from CT-measured right upper lobe bronchus width and diameter of right upper lobe ventilation slot of the DLT. Results: Adequate separation of lungs was achieved in 92.7% of studied population, 90.9% in males, and 95.4% in females. Among these, 54.9% patients required different sized DLT as compared to conventional method. Overall safety of margin of right-sided DLTs was comparable between two methods of DLT selection (median [IQR] 4.8 (3.5–6.8) vs. 6.59 (3.5–7.8), P = 0.317). DLT size with adequate isolation of lung correlated with height, tracheal width (TW) on chest X-ray, and age of the patients. A formula to calculate DLT size based on these variable was derived. Conclusion: CT-measured bronchial width predicts the appropriate DLT size better than conventional method. In the absence of CT scan facility, patient height, age, and chest X-ray TW may be used to predict DLT size with reasonable accuracy.

Does Establishing a Safety Margin Reduce Local Recurrence in Subsegmental Transarterial Chemoembolization for Small Nodular Hepatocellular Carcinomas?

OBJECTIVE: To test the hypothesis that a safety margin may affect local tumor recurrence (LTR) in subsegmental chemoembolization. MATERIALS AND METHODS: In 101 patients with 128 hepatocellular carcinoma (HCC) nodules (1-3 cm in size and < or = 3 in number), cone-beam CT-assisted subsegmental lipiodol chemoembolization was performed. Immediately thereafter, a non-contrast thin-section CT image was obtained to evaluate the presence or absence of intra-tumoral lipiodol uptake defect and safety margin. The effect of lipiodol uptake defect and safety margin on LTR was evaluated. Univariate and multivariate analyses were performed to indentify determinant factors of LTR. RESULTS: Of the 128 HCC nodules in 101 patients, 49 (38.3%) nodules in 40 patients showed LTR during follow-up period (median, 34.1 months). Cumulative 1- and 2-year LTR rates of nodules with lipiodol uptake defect (n = 27) and those without defect (n = 101) were 58.1% vs. 10.1% and 72.1% vs. 19.5%, respectively (p < 0.001). Among the 101 nodules without a defect, the 1- and 2-year cumulative LTR rates for nodules with complete safety margin (n = 52) and those with incomplete safety margin (n = 49) were 9.8% vs. 12.8% and 18.9% vs. 19.0% (p = 0.912). In multivariate analyses, ascites (p = 0.035), indistinct tumor margin on cone-beam CT (p = 0.039), heterogeneous lipiodol uptake (p = 0.023), and intra-tumoral lipiodol uptake defect (p < 0.001) were determinant factors of higher LTR. CONCLUSION: In lipiodol chemoembolization, the safety margin in completely lipiodolized nodule without defect will not affect LTR in small nodular HCCs.

Radiofrequency Ablation of Liver Metastases from Colorectal Cancer: A Literature Review

Liver metastases occur in up to 60% of patients with colorectal cancer, and the control of liver metastases is considered to be of primary importance because it is a critical factor in determining prognosis. Radiofrequency ablation (RFA) therapy is one of the least invasive techniques for unresectable hepatic malignancies and can be performed safely using percutaneous, laparoscopic, or open surgical techniques. The local tumor progression rates after RFA for colorectal liver metastases range from 8.8% to 40.0%, and 5-year survival rates range from 20.0% to 48.5%. No prospective, randomized trials comparing the efficacy of RFA with that of surgical resection for colorectal liver metastases are currently available. However, some retrospective studies have reported that patients who received RFA had a survival rate similar to that observed in surgically treated groups, while other studies have reported better survival among patients who underwent surgical resection. The use of a laparoscopic or open surgical approach allows the repeated placement of RFA electrodes at multiple sites to ablate larger tumors. An accurate evaluation of treatment response is very important for the success of RFA therapy because a sufficient safety margin (at least 0.5 cm) can prevent local tumor progression. This review critically summarizes the current status of RFA for liver metastases from colorectal cancer.

Development of a canine model for recurrent laryngeal injury by harmonic scalpel / 한국실험동물학회지

Various energy devices had been used in thyroid surgery. Aim of study is to develop canine model for recurrent laryngeal nerve injury by harmonic scalpel and to evaluate feasibility of using this model for evaluating the safety use of harmonic scalpel during thyroid surgery. Nine dogs were divided into 3 groups according to distance between harmonic scalpel application and recurrent laryngeal nerve; group 1 (1 mm), 2 (2 mm), and 3 (3 mm). Vocal cord function was assessed pre- and postoperatively using video laryngoscopy. Harmonic scalpel was applied adjacent to left recurrent laryngeal nerve and, two weeks later, right recurrent laryngeal nerve at assigned distances. Recurrent laryngeal nerves were evaluated for subacute and acute morphologic changes. Laryngoscopy demonstrated 3 abnormal vocal cords in group 1, 1 in group 2, and no in group 3 (P=0.020). Subacute histologic changes were observed in nerves with abnormal function. Acute histologic changes were observed 5/8 (62.5%) in group 1, 1/7 (14.3%) in group 2, and not in group 3. We developed canine model for recurrent laryngeal injury. The functional outcomes matched with the histologic changes. These warrant further study to determine the safety margin for energy device in vicinity of recurrent laryngeal nerve.

Consolidative repeat radiofrequency ablation for alpha-fetoprotein negative hepatocellular carcinoma: does it have a role in local tumor control / 中华肝胆外科杂志

Objective To retrospectively evaluate the role of consolidative repeat radiofrequency ablation (CRRFA) based on safety margin (SM) analyses in local tumor control for alpha-fetoprotein (AFP) negative hepatocellular carcinoma (HCC) patients who had been shown to have radiological complete ablation (CA) with radiofrequency ablation (RFA). Methods From July 2002 to July 2009,152 AFP negative HCC patients who were shown to have radiological CA with RFA therapy were retrospectively analyzed. Among them, 110 patients had a SM of less than 1 cm and the other 42 patients had a SM of 1cm or more. Among 110 patients with SM less than 1 cm, fifty nine patients accepted CRRFA within 6 months after the first RFA and 51 did not. From these patients, a narrow SM-CRRFA group (n=41) and a narrow SM-single RFA group (n=37) were enrolled respectively. The wide SM-single RFA group (n= 30) was enrolled from the 42 patients with a SM of 1 cm or more.The LTP (local tumor progression)-free survival rate of the 3 groups were compared with a log-rank test. Results One-, two-, three-, four-, and five-year LTP-free survival rates respectively were 97. 1%, 90.9%, 69.6%, 47.2%, and 33. 0% in the narrow SM-CRRFA patients. 85.9%, 66. 5%,43.5%, 15.8%, and 0. 0%, in the narrow SM-single RFA patients, and were 92.7%, 83.7%,59.3%, 36. 9%, and 9.2% in the wide SM-single RFA patients. There were statistically significant differences (χ2 = 14. 789, P= 0. 001) between the groups. Conclusions An ablation zone with an SM of 1 cm or greater was the most important factor for local control of AFP negative HCC ranging from 3 to 5 cm in diameter. For these patients with a SM of less than 1 cm, CRRFA improved the overall local control outcomes.

Utilización terapéutica de la criocirugía en el melanoma extensivo superficial (spreading) / Therapeutic use of cryosurgery in the spreading superficial melanoma

Se presenta la siguiente revisión bibliográfica, orientada a los colegas médicos, en la práctica general, con la finalidad de obtener un acertado diagnóstico en la evaluación de una lesión tumoral pigmentada, así como describir modalidades terapéuticas existentes para el tratamiento del melanoma superficial de Spreading. Y entre éstos, una prácticamente inusual, como lo es la técnica crioquirúrgica que escapa de los lineamientos convencionales, como son, los que a continuación se menciona: quimioterapia, radioterapia, exsición local, exsición con margen de seguridad, exsición con linfadenectomía, exsición radical, etc. Hay ensayos terapéuticos como: el uso del DNCB (dinitroclorobenzeno), para prueba de sensibilidad de la piel que nos permita valorar el pronóstico del melanoma maligno; si disminuye la sensibilidad, indica malignidad avanzada. Se ha usado el DTIC, Imadozole dicarboxamida más la BCG como prueba terapéutica, así como el uso del corynebacterium-parvum en pacientes post-quirúrgicos, por el riesgo de recurrencia. Debemos mencionar también los ensayos terapéuticos con el antiestrógeno tamoxifeno.

The following bibliographic revision is presented, oriented to the colleagues in general practice with the aim to obtain a correct diagnosis in the assessment of a pigmented tumorous lesion as well as to describe existing therapeutic methods for treatment of spreading superficial melanoma, and among them, one that is practically unusual as it is the cryosurgical technique which is out of the conventional directions as those we mention next: chemotherapy, radio therapy, local excision, excision with margin of safety, excision with lymphadenectomy, radical excision, etc. There are therapeutic trails such as: use of DNCB (dinitrichlorobenzene), as a sensitivity test that allows us to value the prognosis of the malignant melanoma; if sensitivity lessens, I means advanced malignancy. DTIC, Imidazole dicarboxamida has been used, plus BCG as a therapeutic test, as well as corynebacterium-parvum in post-surgical patients, because of the recurrence risk. We must also mention the therapeutic trials with the anti-estrogen tamoxiphene.

Effects of aging on force adaptation during manipulation of a small object using a precision grip / 体力科学

The effects of aging on adaptive force control of precision grip while manipulating a small object were compared between older (84.2±8.9 yrs, n=33) and young adults (19.1±0.24 yrs, n=18) from the following perspectives: (1) adaptation to an unfamiliar object with uncertain physical properties during 16 consecutive lifts ; (2) adaptation to an object with a non-slippery (sandpaper) surface during 12 consecutive lifts, followed by 12 consecutive lifts with a slippery (silk) surface ; and (3) adaptation to objects with different weights (0.49, 0.98, 1.96 and 2.94 N) during 24 lifts (6 consecutive lifts for each weight) .During each trial, grip and load forces were monitored. Safety margin force and slip force were evaluated from the data obtained.<BR>The majority of older adults employed a considerably greater safety margin for an unfamiliar object in the initial trials than did young adults, while the minority of the older adults were able to adapt their safety margin force with a few trials, like the young adults. The older adults who overestimated the safety margin force, however, successfully adjusted their grip force to more optimal levels with repeated lifts, suggesting that the adaptive capability of grip force remained even at 90 years of age. The adaptation of older adults, however, was found to be slower (i. e., required more trials) than that of young adults. Upon encountering surface friction change, the safety margin forces in older adults were more strongly affected by the previous surface condition than those in the young adults. In addition, adaptation to a non-slippery surface seemed more difficult than that to a slippery surface with aging. Upon encountering weight change, older adults showed more difficulties in scaling their safety margin forces according to object weights.<BR>Slower adaptation and difficulty in adaptation to the friction or weight change in older adults may reflect the agerelated decline of tactile sensitivity which impaired the signaling of frictional conditions and various discrete events in the hand. In addition, the lift repetition for force adaptation may possibly reflect the age-related deficit or slowing of central processing capacities related to grip force production.