Stitch retractor—simple and easy technique to retract brain

1. Introduction 

Walter Dandy once wrote while discussing operative technique that “it is evident edema is directly proportional to the amount of insult to the brain during the operation. Gentleness in touching the brain, in traction, in sponging, the use of sharp instruments instead of blunt force in cleavage, are all important in lowering the amount of cerebral edema” [5]. A retractor is an instrument used during surgery for, among other things, holding back structures adjacent to the immediate operative field. During surgery for aneurysms, for lesions located in skull base and sellar- suprasellar tumor where the sylvian fissure is opened, retraction of temporal lobe is required to gain adequate surgical exposure.

At present, many good retractor systems are available. Each system has its own advantages. It is seen that these retractors may cause contusions in the underlying brain. Andrews and Bringas [2] and Andrews and Muto [3] in their study pointed out that approximately 10% of major cranial base tumors and 5% of intracranial aneurysm surgeries have brain retraction injuries. There may even be chances that retraction-related postoperative hematoma can be fatal [11]. Present retractor systems are fixed and rigid, and they also tend to obstruct surgeons' way at times. These retractors may also create glare in the microscope and distract the surgeon. There are various attempts to avoid complications of these with use of sponge pieces as retractors [4], soft microballoon paddy [12], spoon retractor 10, malleable retractor [6], and so on. We have been using this simple and easy method of retraction of brain especially the temporal lobe and cut halves of vermis using the transvermian approach while doing surgery.

1.1. Technique 

In our technique, after making the craniotomy, brain protection is extremely important during arachnoidal dissection and brain separation to create a surgical corridor. Once the sylvian fissure is opened, then 4'0 silk on atraumatic needle is taken to pass through the arachnoid of sylvian fissure side of the temporal lobe, which is usually thickened there. After taking the suture, it is tied to skin or temporalis muscle, and the temporal lobe is retracted very gently as shown in Fig. 1. In this way, even without producing retraction, the temporal lobe can be kept away from the operating field to facilitate surgical dissection.

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Fig. 1. A: Preoperative scan suggestive of suprasellar lesion. B: Four-vessel angiogram suggestive of ICA aneurysm. C: Stitch being taken from the arachnoid after sylvian fissure dissection. D: Dissection in progress after temporal lobe is being retracted away with stitch retractor. E: Clipping and excision of aneurysm with stitch retractor in situ without any evidence of temporal lobe contusion. F: Postoperative scan.

We have also found it quite useful in the intra fourth ventricular tumor surgeries requiring transvermian approach. Using this technique, both halves of the vermis can be kept retracted. It is particularly useful in children where retraction can be quite dangerous to the patient. In Fig. 2, a similar retraction method is shown while doing tumor dissection. Sometimes, to facilitate the suture to stay at the arachnoid where it is thin, it can be coagulated in a little area by using bipolar current at low settings so that the arachnoid becomes thick (Fig. 3).

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Fig. 2. A: Preoperative scan suggestive of vermian SOL. B: Stitch retractor in situ after vermian split for transvermian approach. C: Tumor dissection in progress after cut halves of vermis are retracted with stitch retractor. D: Excision of tumor with stitch retractor in situ without any evidence of contusion. E: Postoperative scan.

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Fig. 3. A: Four-vessel angiogram suggestive of ICA aneurysm. B: Stitch being taken from the arachnoid after sylvian fissure dissection. C: Dissection in progress after temporal lobe is being retracted away with stitch retractor. D: Another stitch retractor used while clipping of aneurysm in situ without any evidence of temporal lobe contusion. E: Nicely exposed aneurysm with both stitch retractors in situ.

2. Discussion 

After the skull is opened, the cerebral perfusion pressure in the area where the brain is retracted can be calculated by the formula rCPP = MAP − BRP. Where rCPP is the measured regional cerebral perfusion pressure (in mm HG), and BRP is the measured brain retraction pressure (in mm HG) [1]. Retraction pressure recorded is equal over the full area of contact, providing the more meaningful measurement rather than simply at one point on the retractor. Horimoto and Tsujimura [9] by means of technetium-99m–labeled hexamethyl-propyleneamine oxime SPECT, the regional CBF in the frontotemporal region of the operated side was studied in 6 patients using retraction and 6 patients without nonretractors. There was reduction in regional CBF in the frontotemporal region of the operated side in 3 patients.

Hongo et al [8] pointed out that it is very difficult for the surgeon to accurately gauge the amount of pressure actually applied to the brain during retraction. The injury caused by such retraction can be focal or generalized depending on the excessive pressure applied or the inappropriate distribution of the pressure. Even strain gauge or gauges attached to the blade has been used [8], but this also has limited use except to distribute force on brain evenly.

The current popular system that is in use—Leyla retractor (Aesculap, Germany), introduced by Yasergil [14]—remains the popular self-retaining retractor. An important problem faced by the surgeon with this retractor system is related to adjustment. It is very difficult to tighten the arm sufficiently to prevent drifting and even secure mounting device at the craniotomy site [7], [13]. Sugita et al [13] reported that both the adjustment knob and extreme length of flexible arm tend to protrude and interfere with the surgeon's hand.

Andrews and Bringas [2] in their study pointed out that approximately 10% of major cranial base tumors and 5% of intracranial aneurysm surgeries have brain retraction injuries. There may even be chances that postoperative hematoma can be fatal to the patient. All the present retractor systems are fixed and rigid, and they also tend to obstruct surgeons way at time as observed by Sugita et al [13]. Sometimes these retractors create glare in the microscope that distracts the surgeon. There are various variables that influence the vulnerability of the brain to different degrees of retraction during surgery, including the presence of subarachnoid hemorrhage, depth of anesthesia, blood oxygen and carbon dioxide levels, and the region of the brain retracted [3].

Various electrophysiological studies like EEG and SSEP are being done for detection of imminent brain damage, which is affected by the depth of anesthesia. To document the monitoring of BRP and cortical activity, a device has been developed—brain retraction sensor, which was patented (United States patent 6916294).This system has the advantage to improve the accuracy and fidelity of measuring intracranial pressure due to retraction. The use of sponge pieces as retractors [4], soft microballoon paddy [12], spoon retractor [10], and malleable retractor [6] has been tried. However, in the case of soft microballoon paddy and malleable retractor, the fixed retractors are still applied.

All of these studies and devices were invented because of the problems that were created by the retractor systems. On the other hand, it is extremely difficult for the operating surgeon to operate without using retraction. In spinal tumor surgeries, dura and arachoid are often retracted with the help of stitches, a very similar principle applied while using this retraction method during our surgery.

Our system allows surgeon to retract the temporal lobe with very little chance of postoperative contusion or hematoma. Continuous retraction to the brain as compared to intermittent retraction is more traumatic to brain [15], but with stitch retractor, continuous retraction is possible. This stitch retractor has the advantage of being kept in use for prolonged time without any damage to the brain secondary to ischemia. The other advantage is that it does not obstruct in any way while doing dissections and surgery as was the problem observed with present retractor systems by Sugita et al [13]. Another advantage is that there is no glare while operating under microscope. The biggest advantage is that it is very cheap, and it costs almost nothing. In our experience with 47 patients, only 1 patient had postoperative hematoma. We have used this stitch retractor in 8 posterior fossa tumors without any complications.

As already mentioned, our retractor is not so useful when the brain if full, angry, and traumatized. Its usefulness is tested in our center for transsylvian approaches and transvermian approach for fourth ventricular operative procedures. We feel that this stitch retractor, which is cheap, simple to use, minimally traumatic, and innovative, will be extremely useful to the surgeons.

3. Conclusion 

The present retractor system is a simple and easy way for retraction because it is minimally traumatic, reducing the insult to the brain. It allows the surgeon to do dissection without any obstruction and glare in the way for prolonged periods. The biggest advantage of the present stitch retractor is that it is very cheap, simple to use, and does not cost to the patient.