Closing the gap: evidence-based surgical treatment of rectus diastasis associated with abdominal wall hernias.

PURPOSE: Rectus diastasis (RD) associated with abdominal hernias present a surgical challenge associated with a paucity in treatment guidelines. The objective of this systematic review is to review surgical techniques and assess complication and recurrence rates of RD in patients with concurrent abdominal hernias. METHODS: PubMed and EMBASE databases were systematically searched, and data extraction was performed on articles which met the inclusion criteria. Pooled analyses of complication and recurrence rates were performed to compare open vs. minimally invasive surgery. Student t tests were performed to compare differences in continuous outcomes. RESULTS: Twenty-eight studies were included in this review. RD can be surgically repaired by both open and laparoscopic approaches using both non-absorbable and absorbable sutures. The majority of the techniques reported included mesh insertion either above the aponeurosis, retromuscular, preperitoneal, or intraperitoneal. Open techniques, compared to laparoscopic approaches, were associated with a significantly higher rate of skin dehiscence (6.79% vs. 2.86%; p = 0.003) and hematoma formation (4.73% vs. 1.09%; p < 0.001) and a significantly lower rate of post-operative seroma formation (2.47% vs. 8.29%; p < 0.001). No significant difference in RD recurrence rates were observed between open and laparoscopic repair (0.22 vs. 0.63%, p = 0.17). CONCLUSION: Both open and laparoscopic surgery are safe and effective methods that can be used to repair RD in patients with RD and concurrent abdominal hernias as evident by the low recurrence and complication rates and almost negligible major complications post repair.

The effect of negative pressure wound therapy on surgical site occurrences in closed incision abdominal wall reconstructions: a retrospective single surgeon and institution study.

PURPOSE: The use of closed incision negative pressure wound therapy (ciNPWT) in abdominal wall reconstruction is heavily debated. The current literature shows mixed results for its efficacy in preventing surgical site occurrences (SSOs), and many of the studies are limited by small sample size or a lack of generalizability. We sought to assess whether the use of prophylactic ciNPWT has an effect on reducing the rate of SSOs. METHODS: Following institutional review board approval, a retrospective analysis of a prospectively collected abdominal wall reconstruction database of a single surgeon at a single institution was completed. Two hundred and seventy patients were reviewed. Univariate and multivariate logistic regressions were performed to assess the effect of each variable on the rate of SSOs. RESULTS: Two hundred and fifty-eight patients (95.56%) met inclusion criteria. One hundred and fifty-nine (61.63%) of these patients received ciNPWT. The median duration of ciNPWT was 6 days. Multivariate logistic regression analysis showed no significant difference in the prevalence of SSOs between groups (OR = 0.843, 95% CI [0.445-1.594], p = 0.598). It did, however, show a significant decrease in the rates of seroma (7.07% vs. 0.63%, p = 0.004). Moreover, skin resection was associated with a decreased rate of SSO (OR = 0.295, 95% CI [0.096-0.911], p = 0.034). CONCLUSIONS: ciNPWT was not associated with a decrease in SSOs following abdominal wall reconstruction but did show a statistically significant decrease in postoperative seromas. Future, large prospective analyses may help further discover the utility of ciNPWT in reducing SSOs.

Optical techniques for 3D surface reconstruction in computer-assisted laparoscopic surgery.

One of the main challenges for computer-assisted surgery (CAS) is to determine the intra-operative morphology and motion of soft-tissues. This information is prerequisite to the registration of multi-modal patient-specific data for enhancing the surgeon's navigation capabilities by observing beyond exposed tissue surfaces and for providing intelligent control of robotic-assisted instruments. In minimally invasive surgery (MIS), optical techniques are an increasingly attractive approach for in vivo 3D reconstruction of the soft-tissue surface geometry. This paper reviews the state-of-the-art methods for optical intra-operative 3D reconstruction in laparoscopic surgery and discusses the technical challenges and future perspectives towards clinical translation. With the recent paradigm shift of surgical practice towards MIS and new developments in 3D optical imaging, this is a timely discussion about technologies that could facilitate complex CAS procedures in dynamic and deformable anatomical regions.

A haptic unit designed for magnetic-resonance-guided biopsy.

The magnetic fields present in the magnetic resonance (MR) environment impose severe constraints on any mechatronic device present in its midst, requiring alternative actuators, sensors, and materials to those conventionally used in traditional system engineering. In addition the spatial constraints of closed-bore scanners require a physical separation between the radiologist and the imaged region of the patient. This configuration produces a loss of the sense of touch from the target anatomy for the clinician, which often provides useful information. To recover the force feedback from the tissue, an MR-compatible haptic unit, designed to be integrated with a five-degrees-of-freedom mechatronic system for MR-guided prostate biopsy, has been developed which incorporates position control and force feedback to the operator. The haptic unit is designed to be located inside the scanner isocentre with the master console in the control room. MR compatibility of the device has been demonstrated, showing a negligible degradation of the signal-to-noise ratio and virtually no geometric distortion. By combining information from the position encoder and force sensor, tissue stiffness measurement along the needle trajectory is demonstrated in a lamb liver to aid diagnosis of suspected cancerous tissue.

A magnetic-resonance-compatible limb-positioning device to facilitate magic angle experiments in vivo.

Owing to their highly ordered structure, tendons and cartilage appear with low signal intensity when imaged using magnetic resonance imaging (MRI) scanners. A significant increase in signal can be observed when these structures are oriented at 55 degrees (termed the magic angle) with respect to the static field B0. There is a clear clinical importance in exploiting this effect as part of the diagnosis of injury. Experimental studies of this phenomenon have been made harder by the practical difficulties associated with tissue positioning and orientation in the confined environment of closed-bore scanners. An MRI-compatible mechatronic system has been developed, which is capable of positioning a number of limbs to a desired orientation inside the scanner, to be used as a diagnostic and research tool. It is actuated with a novel pneumatic motor consisting of a heavily geared-down air turbine, presenting high torques and good accuracy. The system is shown to be magnetic resonance compatible and the results of preliminary trials using the device to image the Achilles tendon of human volunteers at different orientations are presented. An increase of four fold to thirteen fold in signal intensity can be observed at the magic angle.

A review of magnetic resonance imaging compatible manipulators in surgery.

Developments in magnetic resonance imaging (MRI), coupled with parallel progress in the field of computer-assisted surgery, mean that an ideal environment has been created for the development of MRI-compatible robotic systems and manipulators, capable of enhancing many types of surgical procedure. However, MRI does impose severe restrictions on mechatronic devices to be used in or around the scanners. In this article a review of the developments in the field of MRI-compatible surgical manipulators over the last decade is presented. The manipulators developed make use of different methods of actuation, but they can be reduced to four main groups: actuation transmitted through hydraulics, pneumatic actuators, ultrasonic motors based on the piezoceramic principle and remote manual actuation. Progress has been made concerning material selection, position sensing, and different actuation techniques, and design strategies have been implemented to overcome the multiple restrictions imposed by the MRI environment. Most systems lack the clinical validation needed to continue on to commercial products.