Rectus Abdominis Muscle Atrophy and Asymmetry After Pulmonary Lobectomy.

INTRODUCTION: Pulmonary lobectomy can result in intercostal nerve injury, leading to denervation of the rectus abdominis (RA) resulting in asymmetric muscle atrophy or an abdominal bulge. While there is a high rate of intercostal nerve injury during thoracic surgery, there are no studies that evaluate the magnitude and predisposing factors for RA atrophy in a large cohort. METHODS: A retrospective chart review was conducted of 357 patients who underwent open, thoracoscopic or robotic pulmonary lobectomy at a single academic center. RA volumes were measured on computed tomography scans preoperatively and postoperatively on both the operated and nonoperated sides from the level of the xiphoid process to the thoracolumbar junction. RA volume change and association of surgical/demographic characteristics was assessed. RESULTS: Median RA volume decreased bilaterally after operation, decreasing significantly more on the operated side (-19.5%) versus the nonoperated side (-6.6%) (P < 0.0001). 80.4% of the analyzed cohort experienced a 10% or greater decrease from preoperative RA volume on the operated side. Overweight individuals (body mass index 25.5-29.9) experienced a 1.7-fold greater volume loss on the operated side compared to normal weight individuals (body mass index 18.5-24.9) (P = 0.00016). In all right-sided lobectomies, lower lobe resection had the highest postoperative volume loss (Median (interquartile range): -28 (-35, -15)) (P = 0.082). CONCLUSIONS: This study of postlobectomy RA asymmetry includes the largest cohort to date; previous literature only includes case reports. Lobectomy operations result in asymmetric RA atrophy and predisposing factors include demographics and surgical approach. Clinical and quality of life outcomes of RA atrophy, along with mitigation strategies, must be assessed.

KeyLoop retractor for global gasless laparoscopy: evaluation of safety and feasibility in a porcine model.

BACKGROUND: Many surgeons in low- and middle-income countries have described performing surgery using gasless (lift) laparoscopy due to inaccessibility of carbon dioxide and reliable electricity, but the safety and feasibility of the technique has not been well documented. We describe preclinical testing of the in vivo safety and utility of KeyLoop, a laparoscopic retractor system to enable gasless laparoscopy. METHODS: Experienced laparoscopic surgeons completed a series of four laparoscopic tasks in a porcine model: laparoscopic exposure, small bowel resection, intracorporeal suturing with knot tying, and cholecystectomy. For each participating surgeon, the four tasks were completed in a practice animal using KeyLoop. Surgeons then completed these tasks using standard-of-care (SOC) gas laparoscopy and KeyLoop in block randomized order to minimize learning curve effect. Vital signs, task completion time, blood loss and surgical complications were compared between SOC and KeyLoop using paired nonparametric tests. Surgeons completed a survey on use of KeyLoop compared to gas laparoscopy. Abdominal wall tissue was evaluated for injury by a blinded pathologist. RESULTS: Five surgeons performed 60 tasks in 15 pigs. There were no significant differences in times to complete the tasks between KeyLoop and SOC. For all tasks, there was a learning curve with task completion times related to learning the porcine model. There were no significant differences in blood loss, vital signs or surgical complications between KeyLoop and SOC. Eleven surgeons from the United States and Singapore felt that KeyLoop could be used to safely perform several common surgical procedures. No abdominal wall tissue injury was observed for either KeyLoop or SOC. CONCLUSIONS: Procedure times, blood loss, abdominal wall tissue injury and surgical complications were similar between KeyLoop and SOC gas laparoscopy for basic surgical procedures. This data supports KeyLoop as a useful tool to increase access to laparoscopy in low- and middle-income countries.

Low Cost Gastroschisis Silo for Sub-Saharan Africa: Testing in a Porcine Model.

BACKGROUND: Gastroschisis mortality in sub-Saharan Africa (SSA) remains high at 59-100%. Silo inaccessibility contributes to this disparity. Standard of care (SOC) silos cost $240, while median monthly incomes in SSA are < $200. Our multidisciplinary American and Ugandan team designed and bench-tested a low-cost (LC) silo that costs < $2 and is constructed from locally available materials. Here we describe in vivo LC silo testing. METHODS: A piglet gastroschisis model was achieved by eviscerating intestines through a midline incision. Eight piglets were randomized to LC or SOC silos. Bowel was placed into the LC or SOC silo, maintained for 1-h, and reduced. Procedure times for placement, intestinal reduction, and silo removal were recorded. Tissue injury of the abdominal wall and intestine was assessed. Bacterial and fungal growth on silos was also compared. RESULTS: There were no gross injuries to abdominal wall or intestine in either group or difference in minor bleeding. Times for silo application, bowel reduction, and silo removal between groups were not statistically or clinically different, indicating similar ease of use. Microbiologic analysis revealed growth on all samples, but density was below the standard peritoneal inoculum of 105 CFU/g for both silos. There was no significant difference in bacterial or fungal growth between LC and SOC silos. CONCLUSION: LC silos designed for manufacturing and clinical use in SSA demonstrated similar ease of use, absence of tissue injury, and acceptable microbiology profile, similar to SOC silos. The findings will allow our team to proceed with a pilot study in Uganda.

Multidisciplinary Development of a Low-Cost Gastroschisis Silo for Use in Sub-Saharan Africa.

BACKGROUND: Gastroschisis silos are often unavailable in sub-Saharan Africa (SSA), contributing to high mortality. We describe a collaboration between engineers and surgeons in the United States and Uganda to develop a silo from locally available materials. METHODS: Design criteria included the following: < $5 cost, 5 ± 0.25 cm opening diameter, deformability of the opening construct, ≥ 500 mL volume, ≥ 30 N tensile strength, no statistical difference in the leakage rate between the low-cost silo and preformed silo, ease of manufacturing, and reusability. Pugh scoring matrices were used to assess designs. Materials considered included the following: urine collection bags, intravenous bags, or zipper storage bags for the silo and female condom rings or O-rings for the silo opening construct. Silos were assembled with clothing irons and sewn with thread. Colleagues in Uganda, Malawi, Tanzania, and Kenya investigated material cost and availability. RESULTS: Urine collection bags and female condom rings were chosen as the most accessible materials. Silos were estimated to cost < $1 in SSA. Silos yielded a diameter of 5.01 ± 0.11 cm and a volume of 675 ± 7 mL. The iron + sewn seal, sewn seal, and ironed seal on the silos yielded tensile strengths of 31.1 ± 5.3 N, 30.1 ± 2.9 N, and 14.7 ± 2.4 N, respectively, compared with the seal of the current standard-of-care silo of 41.8 ± 6.1 N. The low-cost silos had comparable leakage rates along the opening and along the seal with the spring-loaded preformed silo. The silos were easily constructed by biomedical engineering students within 15 min. All silos were able to be sterilized by submersion. CONCLUSIONS: A low-cost gastroschisis silo was constructed from materials locally available in SSA. Further in vivo and clinical studies are needed to determine if mortality can be improved with this design.

An Accessible Laparoscope for Surgery in Low- and Middle- Income Countries.

Laparoscopic surgery is the standard of care in high-income countries for many procedures in the chest and abdomen. It avoids large incisions by using a tiny camera and fine instruments manipulated through keyhole incisions, but it is generally unavailable in low- and middle-income countries (LMICs) due to the high cost of installment, lack of qualified maintenance personnel, unreliable electricity, and shortage of consumable items. Patients in LMICs would benefit from laparoscopic surgery, as advantages include decreased pain, improved recovery time, fewer wound infections, and shorter hospital stays. To address this need, we developed an accessible laparoscopic system, called the ReadyView laparoscope for use in LMICs. The device includes an integrated camera and LED light source that can be displayed on any monitor. The ReadyView laparoscope was evaluated with standard optical imaging targets to determine its performance against a state-of-the-art commercial laparoscope. The ReadyView laparoscope has a comparable resolving power, lens distortion, field of view, depth of field, and color reproduction accuracy to a commercially available endoscope, particularly at shorter, commonly-used working distances (3-5 cm). Additionally, the ReadyView has a cooler temperature profile, decreasing the risk for tissue injury and operating room fires. The ReadyView features a waterproof design, enabling sterilization by submersion, as commonly performed in LMICs. A custom desktop software was developed to view the video on a laptop computer with a frame rate greater than 30 frames per second and to white balance the image, which is critical for clinical use. The ReadyView laparoscope is capable of providing the image quality and overall performance needed for laparoscopic surgery. This portable low-cost system is well suited to increase access to laparoscopic surgery in LMICs.