Application of PEEP using the i-gel during volume-controlled ventilation in anesthetized, paralyzed patients

Purpose

This prospective, randomized trial was designed to assess whether the i-gel supraglottic airway device is suitable for volume-controlled ventilation while applying positive end-expiratory pressure (PEEP) of 5 cmH₂O under general anesthesia. It was believed that this device might improve arterial oxygenation.

Methods

Forty adult patients (aged 20–60 years) scheduled for elective orthopedic surgery were enrolled in this study. Twenty patients were ventilated without external PEEP [zero positive end-expiratory pressure (ZEEP) group], and the other 20 were ventilated with PEEP 5 cmH₂O (PEEP group) after placing an i-gel device. Volume-controlled ventilation at a tidal volume (TV) of 8 ml/kg of ideal body weight, leak volume, and arterial blood gas analysis were investigated.

Results

The incidences of a significant leak were similar in the ZEEP and PEEP groups (3/20 and 1/20, respectively; P = 0.605), as were leak volumes. No significant PaO₂ difference was observed between the two groups at 1 h after satisfactory i-gel insertion (215 ± 38 vs. 222 ± 54; P = 0.502).

Conclusions

The use of an i-gel during PEEP application at 5 cmH₂O did not increase the incidence of a significant air leak, and a PEEP of 5 cmH₂O failed to improve arterial oxygenation during controlled ventilation in healthy adult patients.     

Robot-assisted Posterior Retroperitoneoscopic Adrenalectomy Using Single-port Access: Technical Feasibility and Preliminary Results

Background

Posterior retroperitoneoscopic adrenalectomy (PRA) has several benefits compared with transperitoneal adrenalectomy in that it is safe and has a short learning curve. In addition, it provides direct short access to the target organ, prevents irritation to the intraperitoneal space, and does not require retraction of adjacent organs.1 ^– 3 We have performed several cases of robot-assisted PRA using single-port access for small adrenal tumors. This multimedia article introduces the detailed methods and preliminary results of this procedure.

Methods

Five patients underwent single-port robot-assisted PRA between March 2010 and June 2011 at our institution. During the procedure, patients were placed in a prone jackknife position with their hip joints bent at a right angle (Fig. 1). A 3 cm transverse skin incision was made just below the lowest tip of the 12th rib (Fig. 2), and the Glove port (Nelis, Kyung-gi, Korea) was placed through the skin incision while maintaining pneumoretroperitoneum (Fig. 3). CO₂ was then insufflated to a pressure of 18 mm Hg to create an adequate working space. A 10 mm robotic camera with a 30-degree up view was placed at the center of the incision through the most cephalic portion of the Glove port. A Maryland dissector or Prograsp forceps (Intuitive Surgical, Inc., Sunnyvale, CA) was placed on the medial side of the incision, and Harmonic curved shears (Intuitive Surgical) were placed on the lateral side of the incision (Fig. 4). Using the Maryland dissector and the harmonic curved shears, the Gerota fascia is opened, perinephric fat is dissected, and the kidney upper pole is mobilized to expose the adrenal gland (Fig. 5). Gland dissection starts with lower margin detachment from the upper kidney pole in a lateral to medial direction (Fig. 6). After dissecting the adrenal gland from surrounding adipose tissue and medial isolation of the adrenal central vein, the vessel is ligated with a 5 mm hemolock clip (Fig. 7). Patient clinicopathologic data were analyzed retrospectively.

Results

The mean patient age was 56.6 ± 8.7 (range, 47–69) years. Right and left side approaches were used in two and three patients, respectively. All cases were adrenal cortical adenoma. The mean tumor size was 1.48 ± 0.28 (range, 1.0–1.7) cm. The mean surgery duration (skin to skin) was 159.4 ± 57.6 (range, 103–245) minutes, and the mean estimated blood loss was 46.0 ± 56.8 (range, 5–120) ml. The average time to oral intake and postoperative hospital stay were 0.65 ± 0.11 (range, 0.54–0.79) days and 4.0 ± 2.23 (range, 3–8) days, respectively. There were no conversions to open surgery or postoperative compli- cations.

Discussion

Some trials of minimally invasive single-access surgery of the adrenal gland have recently been performed.4 ^, 5 However, these new techniques have several limitations as a result of restrictions on instrumentation movement because of the small access ports used and relatively low-quality images produced. The recent introduction of the da Vinci S surgical robot system (Intuitive Surgical) to endoscopic surgery has improved instrumental dexterity and provided the surgeon with an ergonomically designed operating system. This system is also potentially safer and more meticulous in performing operations than endoscopic procedures as a result of a 3-D, magnified, stable operative view.6 ^, 7 The advantages of the da Vinci S surgical robot system and the numerous benefits of the posterior retroperitoneal approach motivated us to utilize single-port robot-assisted PRA. The primary selection criteria were small tumor size and a minimal amount of periadrenal fatty tissue because robot-assisted PRA using single-port access provides a small operative space, which causes manipulation problems when tumors are large. To ensure the safe application of these new techniques, we recommend that novice surgeons begin using single-port robot-assisted PRA for smaller tumors < 2 cm in patients with a body mass index of < 30 kg/m², gradually extending the size and body mass index as they accumulate experience. Although robot-assisted PRA using single-port access could not be compared with the other robotic adrenalectomy techniques in this study, the potential advantages of this approach compared to conventional robot-assisted transperitoneal adrenalectomy include a reduction in postoperative ileus, bacterial contamination, and intestinal complications because the peritoneal cavity is not opened, in addition to a reduction in postoperative pain because of its minimally invasive nature.

Conclusions

Our initial experiences with robot-assisted PRA using single-port access assured us of its safety and feasibility for the resection of small adrenal tumors. Although single-port robot-assisted PRA appears to be safe and feasible, further experience and research is required to optimize patient selection criteria and verify its advantages over the traditional three-incision PRA technique.     

Latissimus dorsi flap coverage of soft tissue defect following below-knee amputation: emphasis on flap design and recipient vessels

High-energy trauma to the lower extremity often results in amputation of the limb. For maximal preservation of limb length during amputation, free tissue transfer is often necessary. In this study, we report our experience of stump coverage using latissimus dorsi musculocutaneous flaps with an emphasis on flap design and recipient vessels. Between January 2005 and September 2010, twelve patients with severe traumatic injuries to the lower leg underwent below-knee amputations with stump coverage using latissimus dorsi free flaps. The primary and secondary cases were approached differently regarding the flap design and recipient vessels. All flaps survived completely. There were 8 primary cases and 4 secondary cases. In the primary cases, the anterior tibial artery was used as the recipient vessel in 6 cases, and in 2 cases, the descending geniculate artery was used. In the secondary cases, the descending geniculate artery was used in all cases. There were two cases of ulceration on the grafted non-weight-bearing site, but after the usage of collagen–elastin artificial dermis, no ulcerations were seen. The latissimus dorsi musculocutaneous flap is the most feasible option for coverage of amputation stumps. In flap design, the width of the skin paddle must match the anteroposterior diameter of the defect at the stump. The latissimus dorsi muscle must sufficiently wrap the bony stump for padding. We recommend using the anterior tibial artery as a recipient vessel in primary cases, and the descending geniculate artery in secondary cases.     

Revolutionizing technologies of nanomicelles for combinatorial anticancer drug delivery

Archives of Pharmacal Research - Insufficient efficacy of current single drug therapy of cancers have led to the advancement of combination drug-loaded formulations. Specifically, polymeric...     

Bacteriomimetic poly-γ-glutamic acid surface coating for hemocompatibility and safety of nanomaterials

Poly-γ-glutamic acid (PGA), a major component of the bacterial capsule, is known to confer hydrophilicity to bacterial surfaces and protect bacteria from interactions with blood cells. We tested whether applying a bacteriomimetic surface coating of PGA modulates interactions of nanomaterials with blood cells or affects their safety and photothermal antitumor efficacy. Amphiphilic PGA (APGA), prepared by grafting phenylalanine residues to PGA, was used to anchor PGA to reduced graphene oxide (rGO) nanosheets, a model of hydrophobic nanomaterials. Surface coating of rGO with bacterial capsule-like APGA yielded APGA-tethered rGO nanosheets (ArGO). ArGO nanosheets remained stable in serum over 4?weeks, whereas rGO in plain form precipitated in serum within 5?minutes. Moreover, ArGO did not interact with blood cells, whereas rGO in plain form or as a physical mixture with PGA formed aggregates with blood cells. Mice administered ArGO at a dose of 50?mg/kg showed 100% survival and no hepatic or renal toxicity. No mice survived exposure at the same dose of rGO or a PGA/rGO mixture. Following intravenous administration, ArGO showed a greater distribution to tumors and prolonged tumor retention compared with other nanosheet formulations. Irradiation with near-infrared light completely ablated tumors in mice treated with ArGO. Our results indicate that a bacteriomimetic surface modification of nanomaterials with bacterial capsule-like APGA improves the stability in blood, biocompatibility, tumor distribution, and photothermal antitumor efficacy of rGO. Although APGA was used here to coat the surfaces of rGO, it could be applicable to coat surfaces of other hydrophobic nanomaterials.     

Comparison of diameters of ipsilateral and contralateral internal mammary arteries by breast MRI in patients with unilateral breast cancer

Purpose

We compared maximal diameters of ipsilateral (IMA) and contralateral (IMA) internal mammary arteries in patients with unilateral breast cancer and analyze the implications of enlargements of ipsilateral or contralateral IMAs in relation to histopathologic factors.

Materials and methods

Of 568 women who underwent breast magnetic resonance imaging (MRI) examinations from January 2009 to May 2012, 196 had unilateral, histologically proven breast cancer. In 156 women, maximal IMA diameters in the second intercostal space were measured by two blinded radiologists in left and right sides using nonenhanced axial T2-weighted turbo spin-echo sequence images.

Results

In the 156 study patients, mean maximal diameter of ipsilateral IMAs (2.37 ± 0.60 mm) was significantly larger than that of contralateral IMAs (2.03 ± 0.58 mm) (p = 0.00). Ipsilateral IMA enlargement was present in 66.7 % of the patients (104 of 156). Furthermore, ipsilateral IMA enlargement was found to be significantly associated with human epidermal growth factor receptor-2 (HER-2) expression (p = 0.039).

Conclusions

Maximal IMA diameter was significantly greater in ipsilateral sides in breast cancer patients. Findings suggest ipsilateral IMA enlargement detected by MRI might be a useful additional predictor of HER-2 expression in unilateral breast cancer.

     

Reconstruction of the lateral malleolus and calcaneus region using free thoracodorsal artery perforator flaps

Reconstruction of the lateral malleolus or calcaneus region is challenging because of poor vascularity, minimal presence of soft tissue, and difficulties with flap positioning during and after the operation. In many cases, local flaps are limited in terms of size, durability, and vascularity. Free tissue transfer can be useful for complicated wounds. We report here on the results of the reconstruction in this region using free thoracodorsal artery perforator flaps. Between October 2010 and October 2013, 16 cases of lateral malleolus or calcaneus defects were reconstructed using free thoracodorsal artery perforator flaps. The defects varied from 2 × 5 cm² to 12 × 16 cm², and the flaps from 3 × 5 cm² to 10 × 15 cm². Two cases were reconstructed using chimeric‐pattern flaps. Only the superficial adipose layers were harvested for all the flaps, without further thinning or debulking process. Five cases with complications occurred, including three cases of partial necrosis of the flap and two cases of venous congestion caused by thrombosis and compression of the venous pedicle, and one flap was totally lost. The mean follow‐up duration was 11.8 months. All the patients were able to wear shoes. All but one were able to walk. The thoracodorsal artery perforator flap can be made super‐thin, allowing patients to wear shoes, and it can be harvested in a chimeric‐pattern for complex defects. Therefore, it may represent a viable alternative choice for the reconstruction of the lateral malleolus and calcaneus region. © 2015 Wiley Periodicals, Inc. Microsurgery 36:198–205, 2016.     

The Interaction Between Prenatal Exposure to Home Renovation and Reactive Oxygen Species Genes in Cord Blood IgE Response is Modified by Maternal Atopy

Purpose

Although home renovation exposure during childhood has been identified as a risk factor for the development of allergy, there is limited information on the association between prenatal exposure to home renovation and cord blood (CB) IgE response. The aims of this study were to identify the effect of prenatal exposure to home renovation on CB IgE levels, and to investigate whether this exposure interacts with neonatal genes and whether the effect can be modified by maternal atopy.

Methods

This study included 1,002 mother-neonate pairs from the COhort for Childhood Origin of Asthma and allergic diseases (COCOA). Prenatal environmental factors were collected using a questionnaire. The levels of CB IgE were measured by the ImmunoCAP system, and DNA was extracted from CB.

Results

Exposure to home renovation during the prenatal period was associated with significantly higher levels of CB IgE only in neonates from atopic mothers, and the effect of renovation exposure on CB IgE levels persisted from 31 months before birth. Furthermore, prenatal exposure to home renovation increased the risk of CB IgE response interacting with polymorphisms of NRF2 and GSTP1 genes only in neonates from atopic mothers.

Conclusions

Maternal atopy modified the effect of prenatal exposure to home renovation on CB serum IgE response as well as the interaction between the exposure and neonatal genes involved in the oxidative stress pathway. These findings suggest that the genetically susceptible offspring of atopic mothers may be more vulnerable to the effect of prenatal exposure to home renovation on the development of allergy.     

Surgical outcome of synchronous second primary cancer in patients with gastric cancer

PURPOSE: In order to improve the likelihood of curative and safe gastric surgery, this study investigated the clinical features and surgical outcomes of gastric cancer with a synchronous cancer. PATIENTS AND METHODS: The clinicopathological data of 10,090 gastric cancer patients at Samsung Medical Center from September 1994 to December 2006 were retrospectively analyzed. Of them, 90 patients with gastric cancer and a synchronous second primary cancer underwent simultaneous surgery for gastric cancer and second primary cancer. The clinicopathological characteristics of the patients, surgical outcome, and prognosis were examined. RESULTS: The most common synchronous second primary cancer was colorectal cancer (37 patients), followed by hepatocellular carcinoma (13 patients), renal cell carcinoma (11 patients), and pancreatic carcinoma (5 patients). The incidence of a second primary cancer in the gastric cancer patients was higher than the incidence in the general population. Stage I gastric cancer patients had more synchronous cancers than stage II patients (59 vs. 31). Postoperative complications were encountered in 7 patients. Four patients underwent reoperation. Two patients died from hepatic failure and leakage of esophagojejunal anastomosis. The 5-year survival rate of stage I and II gastric cancer was 61% and 39%, respectively. CONCLUSION: Since gastric cancer patients with a synchronous second primary cancer are not rare, the possibility of synchronous cancers in gastric cancer patients should be considered. The prognosis of early stage gastric cancer patients with a synchronous second primary cancer was influenced more by the presence of the second primary cancer than by the gastric cancer itself.