The Value of Physicians as Part of a Helicopter Emergency Medical Services Crew: A Review.

OBJECTIVE: The benefit and utility of a physician on a US-based air ambulance is an often-debated topic in the prehospital setting. There remains the question of what, if any, effect a physician crewmember has on patient outcome. Our goal was to assess the literature to date and determine if there exists a benefit to staffing air ambulances with physicians. METHODS: PubMed and Cochrane databases were searched for English language studies from 1980 to 2020 using the terms "flight physician" and "physician-staffed helicopter." Studies were chosen for inclusion based on the presence of a comparison of physician-staffed crews with non-physician-staffed crews. The included studies had their references reviewed for additional studies meeting the inclusion criteria. RESULTS: A total of 19 articles were included, and their overall opinion of the benefit of a physician was assessed. Ten studies demonstrated a benefit, 8 showed no benefit or favored a nonphysician crew, and 1 was equivocal. CONCLUSIONS: Although some studies showed a benefit to having physicians staff an air ambulance, some showed no benefit, leaving our findings inconclusive. More data are needed to determine if the inclusion of these crewmembers has a positive effect on patient outcomes.

A systematic review and meta-analysis of variations in branching patterns of the adult aortic arch.

OBJECTIVE: The aortic arch (AA) is the main conduit of the left side of the heart, providing a blood supply to the head, neck, and upper limbs. As it travels through the thorax, the pattern in which it gives off the branches to supply these structures can vary. Variations of these branching patterns have been studied; however, a study providing a comprehensive incidence of these variations has not yet been conducted. The objective of this study was to perform a meta-analysis of all the studies that report prevalence data on AA variants and to provide incidence data on the most common variants. METHODS: A systematic search of online databases including PubMed, Embase, Scopus, ScienceDirect, Web of Science, SciELO, BIOSIS, and CNKI was performed for literature describing incidence of AA variations in adults. Studies including prevalence data on adult patients or cadavers were collected and their data analyzed. RESULTS: A total of 51 articles were included (N = 23,882 arches). Seven of the most common variants were analyzed. The most common variants found included the classic branching pattern, defined as a brachiocephalic trunk, a left common carotid, and a left subclavian artery (80.9%); the bovine arch variant (13.6%); and the left vertebral artery variant (2.8%). Compared by geographic data, bovine arch variants were noted to have a prevalence as high as 26.8% in African populations. CONCLUSIONS: Although patients who have an AA variant are often asymptomatic, they compose a significant portion of the population of patients and pose a greater risk of hemorrhage and ischemia during surgery in the thorax. Because of the possibility of encountering such variants, it is prudent for surgeons to consider potential variations in planning procedures, especially of an endovascular nature, in the thorax.

The surgical anatomy of the sural nerve: An ultrasound study.

The aim of this study was (a) to examine the anatomy of the sural nerve (SN) in a sample of 30 patients and (b) to analyze the incidence of different origins of the SN, and the distance of the SN from planned arthroscopic portals. An ultrasound (USG) examination of the SN was performed bilaterally on thirty healthy patients with no history of surgery or trauma of the lower limb. The SNs were classified into six main types of pattern, with an additional category for new and unclassified types. Each of Types 1 and 3 had two subdivisions. The distances from the superior border of the calcaneal tuberosity to the three simulated arthroscopy portal sites (Z1, Z1.5, Z2) to the SN were measured. A total of 30 patients (n = 60 limbs) with an average age of 27 ± 7.5 years were examined and the SN was visualized in all cases. The most common origin was Type 3A, accounting for 30% of limbs. Type 2 was the second most common seen in 18.3%. The distances of the SN from arthroscopic portal placement sites above the lateral malleolus were 2.07 ± 0.39 cm at the Z1 portal, 2.15 ± 0.38 cm at Z1.5, and 2.28 ± 0.33 cm at Z2. The variability in the anatomy of the SN warrants the use of USG to locate it accurately, thus preventing iatrogenic injury when portals are placed for arthroscopy, improving proper administration of anesthesia, and helping to localize the nerve for graft harvesting. Clin. Anat. 31:450-455, 2018. © 2017 Wiley Periodicals, Inc.

The evidence-based surgical anatomy of the popliteal artery and the variations in its branching patterns.

OBJECTIVE: The goal of our study was to analyze the prevalence of branching pattern variations in the popliteal artery (PA) along with morphometrics of the PA to better address its importance in disease and vascular surgical procedures. METHODS: An extensive search for the PA and its anatomic variations was done in the major online medical databases. The anatomic data found were extracted and pooled for a meta-analysis. RESULTS: A total of 33 studies (N = 12,757 lower limbs) were included in the analysis. The most common variant was a division of the PA below the knee into the anterior tibial artery and a common trunk for the posterior tibial and peroneal arteries, with a prevalence of 92.6% (95% confidence interval [CI], 90.2-93.8). The second most common variation was a trifurcation pattern of all three branches dividing within 0.5 cm of each other, with a prevalence of 2.4% (95% CI, 1.4-3.5). Of the three studies that reported the diameter of the PA at the level of the subcondylar plane, a mean diameter of 8 mm (95% CI, 7.29-8.70) was found. CONCLUSIONS: The PA most commonly divides below the knee into the anterior tibial artery and the common trunk of the posterior tibial artery and the peroneal artery. Knowledge of the prevalence of possible variations in this anatomy as well as morphometric data is crucial in the planning and execution of any surgical intervention in the area of the knee.

Injury to the infrapatellar branch of the saphenous nerve during tendon graft harvesting for knee ligament reconstruction: An ultrasound simulation study.

The clinical anatomy of the infrapatellar branch of the saphenous nerve (IPBSN) is of particular importance during operations in the area of the knee, especially when material for anterior cruciate ligament reconstruction is harvested. The nerve can easily be injured during the harvesting procedure, leading to postoperative complications that reduce quality of life. Three different skin incisions are commonly used during hamstring tendon harvesting: horizontal, vertical, and oblique. The aim of this ultrasound simulation study was to assess the risk of IPBSN injury associated with the type of skin incision and the point-of-emergence of the IPBSN relative to the sartorius muscle. Thirty healthy volunteers (60 lower limbs) were recruited for identification of the IPBSN. When it was found, using a high-frequency ultrasound probe, three different 3 cm skin incisions over the pes anserinus were simulated. Vertical, horizontal, or oblique lines simulating incisions were marked over the pes anserinus and ultrasound was used to visualize the structures that could be injured during the marked incisions. The IPBSN was visualized in 58 lower limbs (96.7%). The results of the simulation study indicated that the vertical incision should be avoided during hamstring tendon harvesting, as it is associated with a significantly higher risk of injury (25.9%) to the IPBSN than the horizontal (3.5%) or oblique (8.6%) incisions. We recommend that a preoperative ultrasound assessment of IPBSN anatomy be performed to minimize the risk of iatrogenic injury to the nerve and associated complications. Clin. Anat. 30:868-872, 2017. © 2017 Wiley Periodicals, Inc.

Anatomical variability and histological structure of the ulnar nerve in the Guyon's canal.

OBJECTIVES: The goal of our study was to analyze the prevalence of variations, branching patterns, and histology of the ulnar nerve (UN) in Guyon's canal to address its importance in hand surgery, particularly decompression of the UN. METHODS: Fifty fresh cadavers were dissected bilaterally, and the nerve in the area of Guyon's canal was visualized. Samples for histology were also taken and prepared. The collected data were then analyzed. RESULTS: Morphometric measurements of the hands and histological studies were not found to have significant differences when compared by left or right side or by sex. Three major branching patterns were found, with division into deep and superficial UN being the most common (85%). Additional findings included a majority (70%) presenting with a cutaneous branch within the canal and/or with an anastomosis of its distant branches with those of the median nerve (57%). CONCLUSION: The UN is most commonly found to divide into a superficial and deep ulnar branch within Guyon's canal. However, additional branches and anastomoses are common and should be taken into careful consideration when approached during surgery in the area, particularly during decompression procedures of Guyon's canal.

Cadaveric Prehospital Amputation: Which Reciprocating Saw Blade Offers the Most Efficient Amputation.

OBJECTIVE: Field amputations are a low-frequency, high-risk procedure. Many prehospital personnel utilize the reciprocating saw. This study compares the efficiency, speed, and degree of tissue damage of different reciprocating saw blades found commercially. METHODS: Amputations were performed on two human cadavers at different levels of the upper and lower extremities. Four different blades were used, each with a different teeth-per-inch (TPI) design. The amputations were timed, blade temperature was recorded, subjective operator effort was obtained, amount of splatter was evaluated, and an orthopedic physician evaluated the extent of tissue damage and operating room repair difficulty. RESULTS: The blade with fourteen TPI was superior in overall speed to complete the amputations at 1.07 seconds per one centimeter of tissue (SD = 0.49 seconds) and had the lowest fail rate (0/8 amputations). The three TPI, six TPI, and ten TPI blades all required a "rescue" technique and were slower. The blade with fourteen TPI caused the least amount of tissue damage and was deemed the easiest to repair. Secondary outcomes demonstrated the fourteen TPI blade had generated the least amount of heat and produced the least amount of splatter. All blades had a perceived effort of "easy" to complete the amputation. CONCLUSION: While all blades were able to achieve an amputation, the overall recommendation is use of a fourteen TPI blade. It did not require any rescue techniques, provided the most straightforward amputation to repair, had the least amount of biohazard splatter and temperature increase, and was the fastest blade overall.

The surgical anatomy of the superficial and deep palmar arches: A Meta-analysis.

INTRODUCTION: The following study aimed to find the pooled prevalence estimate of anatomical variations in the palmar vasculature, namely the superficial palmar arch (SPA) and the deep palmar arch (DPA). The importance of understanding the vasculature of the hand has become critical with the increasing use of hand microsurgery. METHODS: Major online medical databases (PubMed, EMBASE, ScienceDirect, and Web of Science) were extensively searched for terms pertaining to the SPA, the DPA, and their anatomy and variations. Articles reporting data on the SPA and/or the DPA were collected and their data extracted. Furthermore, a reference search was performed, allowing to pinpoint any articles that were not previously found. The collected data were analyzed using MetaXL 5.3. RESULTS: The analysis included 36 studies (n = 4841 palmar arches). The SPA was found to be complete in 81.3% of cases, with the radioulnar anastomosis being the most common variant (72.0%). The incomplete SPA was present in 18.7% of cases, with the ulnar artery supplying the third finger from both radial and ulnar side as the most prevalent in 34.8%. The DPA was found to be complete in 95.2% of cases. CONCLUSION: In this study, the SPA was predominantly complete, with the anastomosis between the radial and the ulnar artery being most prevalent. Furthermore, the DPA was also complete in the vast majority of cases. The palmar arches and their variations should be kept in mind when considering the use of palmar vasculature for cardiac catheterization and other medical procedures, due to the risk of iatrogenic ischemic hand complications.

Surgical anatomy of the sciatic nerve: A meta-analysis.

The sciatic nerve has varying anatomy with respect to the piriformis muscle. Understanding this variant anatomy is vital to avoiding iatrogenic nerve injuries. A comprehensive electronic database search was performed to identify articles reporting the prevalence of anatomical variations or morphometric data of the sciatic nerve. The data found was extracted and pooled into a meta-analysis. A total of 45 studies (n = 7068 lower limbs) were included in the meta-analysis on the sciatic nerve variations with respect to the piriformis muscle. The normal Type A variation, where the sciatic nerve exits the pelvis as a single entity below the piriformis muscle, was most common with a pooled prevalence of 85.2% (95%CI: 78.4-87.0). This was followed by Type B with a pooled prevalence of 9.8% (95%CI: 6.5-13.2), where the sciatic nerve bifurcated in the pelvis with the exiting common peroneal nerve piercing, and the tibial nerve coursing below the piriformis muscle. In morphometric analysis, we found that the pooled mean width of the sciatic nerve at the lower margin of the piriformis muscle was 15.55 mm. The pooled mean distance of sciatic nerve bifurcation from the popliteal fossa was 65.43 mm. The sciatic nerve deviates from its normal course of pelvic exit in almost 15% of cases. As such we recommend that a thorough assessment of sciatic nerve variants needs to be considered when performing procedures in the pelvic and gluteal regions in order to reduce the risk of iatrogenic injury. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1820-1827, 2016.