82 Ali Abdel Raheem1 & Koon Ho Rha2 1 Minimally Invasive Urological Surgery Unit, Tanta University Hospital, Tanta, Arab Republic of Egypt 2 Department of Urology, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea The evolution of laparoscopic and robotic surgery has expanded to accomplish more in reconstructive and complex urological procedures. For patients to get benefit from minimally invasive surgery (MIS) surgeons must first develop and gain proficiency with minimally invasive surgical skills required for these advanced surgeries. The skillset required for these reconstructive surgeries is very different from traditional open surgery; accordingly, both standard laparoscopic and robot‐assisted procedures are associated with definite learning curves [1, 2]. Initially, laparoscopic reconstructive urologic procedures such as radical prostatectomy, partial nephrectomy, pyeloplasty, radical cystectomy, and urinary diversion were technically demanding, even in the most experienced hand; however, with the rapid improvement of laparoscopic instruments, and innovation of different clips, staplers, and suturing materials, intracorporeal suturing became much more efficient, minimizing patient morbidity while maintaining success rates and surgical efficiency. With the introduction of the da Vinci® surgical system (Intuitive Surgical, Inc., Sunnyvale, CA, USA) in the last decade, robotic surgery eliminated the early steep learning curve for novices, and at the same time improved the ergonomics of motion for experts, which may have implications for highly complex reconstructive procedures in limited workspaces (e.g. radical prostatectomy) [3]. Proper hemostasis is considered a critical key issue for successful reconstructive MIS. Precise tissue visualization during robotic and laparoscopic surgeries can be attained only in a bloodless field. Bleeding must be adequately controlled from the first attempt because it becomes more difficult to control in subsequent attempts. Prevention of bleeding requires from surgeons the timely and appropriate use of this innovative technology. A variety of major hemostatic modalities have evolved in the field of MIS (Box 82.1). In this chapter we review in detail the mechanical methods commonly used in hemostasis and frequently applied during reconstructive MIS, namely “sutures, clips, and staplers.” During MIS, advanced surgical skills such as suturing and knot tying are required for many complex reconstructive procedures. Laparoscopic suturing requires skill and dexterity; the surgeon has an extremely restricted space to maneuver the needle and the 2D vision affords limited depth of perception. In addition, the loss of tactile feedback in laparoscopic surgery often represents a barrier to developing a proficiency in using needle drivers in a standardized way. In robotic surgery, tactile feedback is replaced by haptic feedback. Recent improvements in minimally invasive instrumentation have given surgeons and urologists easier methods of suturing and tying. Tissue reapproximation is an important step during suturing, and many factors are important to make it reproducible, such as adequate port placement site, proper suture type and needle selection, understanding the relationship between the tissue, camera, and ports by the operating surgeon. Moreover, the use of mechanical suturing devices may improve efficiency and accuracy during suturing. The choice of suture is determined by a balance between the type of surgery, the characteristics of different anatomical layers that requires reconstruction, and the characteristics of available suture materials. Certain types of suturing materials can be particularly difficult to work with due to their stiffness and tendency to resist deformation, and forming the slipknots to close wounds and surgical incisions requires great skill. The characteristics of various suture materials are summarized in Box 82.2. Recently, an absorbable unidirectional barbed suture (V‐Loc™180, Covidien, Mansfield, MA, USA) (Figure 82.1) has been introduced and has gained popularity in reconstruction of the urethrovesical anastomosis during radical prostatectomy. The unidirectional barbed suture has many advantages: it makes the anastomosis easier in a shorter time period compared to the nonbarbed monofilament suture, it improves tissue handling and decreases the tension placed by the assistant on the running suture during the anastomosis while re‐approximating the urethra and bladder neck, it prevents slippage once the bladder neck and urethral tissue are re‐approximated, and the tissue stays in place and does not migrate. In addition, it eliminates the risk of erosion of the Lapra‐Ty® clips used to secure the posterior urethral reconstruction [4, 5]. Figure 82.1 V‐Loc™ 180 suture. The length of the suture used during MIS varies and depends on its type and application. For extracorporeal knot tying, maintaining a long suture length (80–120 cm) is required to allow passage of the suture ends outside the trocar. On the other hand, intracorporeal knot tying requires a shorter length. For example, 8–10 cm length is adequate for simple interrupted sutures. For running sutures an extra 10–12 mm suture length is needed for each additional stitch. Running locking sutures require additional 20–25 mm length per stitch. Adequate length should be maintained for knot tying at the end of suturing to avoid stress on the reconstructed tissue [6]. The surgical needle has three major parts: the tip (or needle point), the needle itself (body), and the swage (needle back where the suture is attached). The diameter (the distance between the needle point and the swage) is known as the chord length. The needle may be curved, with a radius of between 1/4 and 5/8 of a circle, or straight. The tip may be triangular with either conventional cutting (sharp edge on the inner arc) or reverse cutting (sharp edge on the outer arc). The latter has less chance of tissue tearing during suturing. The needle body may be flattened to facilitate grasping it and to reduce twisting during suturing. When using a curved needle, it is best to grasp it halfway along the needle arc for better suture control. Likewise, when using a straight needle, placement of the needle holder in the middle allows for more precise needle placement and suturing. Successful needle holding requires alignment of both the tissue and needle. Successful needle entry into the abdominal space is the first step of suturing. The commonest entry route is through the trocar lumen, which requires adequate knowledge of needle sizes, shapes, and different trocar diameters. Grasping the needle 2 cm proximal to its swage facilitates its passage together with the needle driver into the abdominal cavity through the trocar, and minimizes risk of trocar valve mechanism damage. Needle entry through the abdominal wall is an uncommonly used route. This technique is used particularly when a stay suture is required for temporary traction during certain reconstructive urologic surgery, such as pyeloplasty. Straight needles pass through the abdominal wall, then the target tissue, and finally through the abdominal wall again and are clamped outside the abdominal cavity to facilitate traction and countertraction. The application of this technique obviates the need for extra trocar insertion for retraction purposes during surgery. A variety of laparoscopic needle drivers are available in several different configurations and can be used based on surgeon preference or type of surgery. Needle driver jaws are divided into four main categories: straight, curved right, curved left, and self‐righting. Recently, needle drivers with an articulating tip have become available; these can be controlled by angling the instrument’s handle. Theoretically, such devices might offer greater maneuverability and efficiency when compared to nonarticulating types, but they have a steeper learning curve [7]. Needle control and the performance of precise freehand laparoscopic suturing is determined by the needle stability within the driver. An ideal needle driver is characterized by the following properties: it is light with an easy unlocking mechanism, and provides firm grip when driven through the tissues in a direct path [8]. The various features of robotic surgical systems, such as stereoscopic 3D vision, magnified view, wristed instruments, and tremor filtration, are presumed to improve performance in laparoscopic tasks. The increase in degrees of freedom for the instrument’s tip (seven degrees of freedom) and 90° of articulation which are used inside the human body has led to better instrument tip control in a more natural and fluid flight path (Figure 82.2). The net result is increased dexterity with easier and more accurate suturing in a minimally invasive fashion. Various types of robotic needle drivers are available, including “fine micro‐forceps used for suturing the fine structures during cardiovascular surgery and during nerve anastomosis, and a mega‐needle driver used for suturing of larger and thicker tissues” (Figure 82.2). The SutureCut™ needle driver is a new needle driver provided with an integral cutting blade for efficient cutting of suture after knot tying. Figure 82.2 Two types of robotic needle drivers from Intuitive Surgical, Inc.: (a) fine micro‐forceps and (b) mega‐needle driver. A variety of knot types are used in laparoscopy. The most common ones are listed in Box 82.3. For this knot both ends of the suture must be pulled in opposite directions in the same plane with uniform tension. It is incomplete, unreliable, and has a tendency to untie. For this knot each thread has a different role; one remains passive and inactive during the tying process, while the other is the active thread which forms the knot by wrapping around the passive one. Similar to the half knot, the slipknot is incomplete and unreliable; it is also an asymmetric knot that cannot maintain approximation of wound edges. This is a series of half knots and/or slipknots which provide maximum grip to the knot. Both the half knot and the slipknot are considered the cornerstones of the knot (e.g. square, surgical, or slip), which is formed from blocking sequences of two or more slipknots and/or half knots. Suturing techniques during laparoscopic suturing are divided into two types: intracorporeal and extracorporeal suturing. The intracorporeal knot is a challenging technique, especially for junior laparoscopists, and generally has a steep learning curve. During intracorporeal suturing, the knot is made inside the abdominal cavity using two instruments – either two needle drivers or one needle driver and one assistance forceps, depending on surgeon preference. For easy interrupted suturing, it is vital to keep the tail at the terminal end relatively short before tying a knot. This is because a long tail suture may be difficult to locate if adhered to the abdominal viscera. When this occurs, it requires further cinching movements to bring the knot down to the target tissue, which makes knot tying more difficult at the other end of the suture line. Meanwhile, the running is difficult during the tying of the second knot because of the short remaining suture length available while maintaining constant tension on the first knot. An example of a commonly used intracorporeal knot is the square knot. In a certain circumstances it becomes very useful for the surgeon to know how to convert a square knot into a sliding knot when undue tension is applied to the target tissue. After placing two half hitches in the suture, no further cinching down to the tissue is needed. Instead, the free suture end is grasped and tensioned, converting the square to a slipknot, while pushing the knots towards the target tissue with the free instrument. In order to secure the knot properly, additional half hitches may be applied. During extracorporeal suturing, the knot is made outside the abdominal cavity, then it is pushed intracorporeally using a knot pusher, such as slipknot or Roeder’s knot pusher. Various types of extracorporeal knots are available: nonsliding “static” knots (e.g. square knot, half hitches, and revo knot) and sliding knots (e.g. hangman’s knot, Roeder knot, Lieurance Modified Roeder knot, Meltzer’s knot, Tennessee slider, Tayside’s knot, Weston slipknot). The general drawbacks of the extracorporeal technique are as follows: To our knowledge, the square knot and the Roeder’s knot are the most common types of extracorporeal knots. They are described below. This is formed of alternating half knots and then cinched using the knot pusher by advancing it through the trocar down to the tissue. A surgical knot is placed to maintain adequate tension locally at the tissue level while the second half knot is being performed. Tension is maintained on the free ends of the suture, while advancing the knot pusher. To ensure a true square knot the alternating half knots need to be in opposite directions. This was the first knot described in laparoscopic surgery. Roeder’s knot is easy to assemble and place, secure, and is a cost‐effective alternative to intracorporeal suturing and staples during laparoscopic surgery. Its advantage over the square knot is that the entire knot is entirely formed before advancing it into the intracorporeal space. It may be useful in the ligation of somewhat bulky tissue (e.g. the dorsal venous complex) owing to its slip feature. To form the knot, one short limb (the post) and one long limb (the loop) are made, and then a half hitch is placed. The loop is thrown around the post several times depending on the suture material used (braided and gut‐based sutures require 3–5 loops while monofilament sutures require 5–7 loops). The loop is then thrown around both limbs and past the tail of the loop limb between the last two loops. Finally, the loop is thrown only around the post limb. The knot is tensioned and pushed into the joint with a knot pusher on the post limb. Once the initial knot is in position, additional half hitches may be placed for security. Knot‐tying devices may be used to secure the ends of both running and interrupted sutures. The Lapra‐Ty® (Ethicon, Cincinnati, OH, USA) is an absorbable one‐piece clip molded from the polymer poly(p‐dioxanone) (Figure 82.3a). It is delivered by a reusable 10 mm clip applier (33 cm or 45 cm length). Clips are designed as anchors and secure each end of a single strand of 2‐0, 3‐0, or 4‐0 coated Vicryl® (polyglactin 910) suture for soft tissue approximation for a period of up to 14 days. It eliminates the need for intracorporeal knot‐tying and frees the bedside assistant from keeping traction on one side while making the opposite half of the anastomosis. The Lapra‐Ty clip provides a stable tension on the suture and allows for creation of a safe, watertight anastomosis (e.g. during vesicourethral anastomosis of radical prostatectomy) (Figure 82.3b). Suture lines tied with a Lapra‐Ty clip can be further cinched by pulling the suture and applying an additional clip under the previously placed one. This provides a greater flexibility to the surgeon in securing suture lines to the desired level of tension [9]. Another advantage of the Lapra‐Ty clip is its usefulness in shortening the time needed to complete time‐sensitive tasks such as renorrhaphy during partial nephrectomy (Figure 82.3c). In addition, in the case of a short remaining suture length making it difficult to tie the knot, Lapra‐Ty could be applied easily. It should be borne in mind that because of a concern regarding the risk of developing an inflammatory reaction, it is better to apply it on the final knot of running sutures. Figure 82.3 (a) The Lapra‐Ty® (Ethicon) and its metal applicator. (b) Application of Lapra‐Ty clip at the terminal end of a running 3‐0 barbed suture (V‐Loc 180) after complete vesicourethral anastomosis during Retzius‐sparing robot‐assisted radical prostatectomy. (c) Application of Lapra‐Ty clip at the terminal end of a running 3‐0 Vicryl suture for renorrhaphy during right‐side robot‐assisted partial nephrectomy. The Ti‐Knot TK5® (LSI Solutions, Rochester, NY, USA) is another “knot‐tying” device. It delivers titanium knot “non‐reactive material” to mechanically fasten a suture and automatically cuts away excess suture in one step. It requires an extracorporeal loading of the suture into the device, and both ends of the suture must be maintained at length to allow the instrument to be loaded extracorporeally. Once loaded, the device is introduced intracorporeally, the desired tension is achieved, and a titanium knot is deployed, which locks the suture in place. The Ti‐Knot titanium knot can be applied safely during laparoscopic ligation and control of the dorsal vein complex [10] and renal arteries [11]. However, the additional costs related to the use of this disposable device preclude its widespread use. Since laparoscopic suturing is a technically demanding task, additional instruments have been developed to facilitate suturing. The Endo Stitch™ (US Surgical, Norwalk, CT, USA) suturing device was developed to facilitate suture placement and knotting of advanced reconstructive laparoscopic procedures (e.g. laparoscopic dismembered pyeloplasty and bladder neck suspension) by passing a small needle with its secured suture back and forth between its jaws. After each pass, the needle is locked temporarily in place until the instrument handle is squeezed again to transfer it to the other arm. A 10 mm port is required for its use. It reduces the amount of time needed for placement of stitches and knot tying compared to conventional suturing [12, 13]. It has some disadvantages: its short needle cannot pass through thick tissue so cannot be used for reconstructive surgery requiring large bites, such as renorrhaphy during partial nephrectomy; in addition, it increases the cost of the case as it is disposable and needs reloading. The Suture Assistant® (Ethicon) and Reload Units are used in minimally invasive surgical applications. The Suture Assistant is a 5 mm sterile, single‐patient‐use instrument designed to secure suture knots intracorporeally. It is disposable and uses dedicated reloads. The Sew‐Right® SR5® (LSI Solutions, Rochester, NY, USA) is a reloadable 5 mm suturing device that uses two built‐in needles to place a simple suture precisely through even a relatively thick tissue. Its needle passes parallel to the instrument shaft. With a single squeeze of the lever against the handle, the first needle passes through the tissue. The needle automatically captures the suture and pulls it back through the tissue to complete the driving of the suture. The second needle is then selected to take a second bite. Once the suture is complete, the instrument is disengaged from the tissue, and a titanium knot is passed onto the suture to secure it. It is a disposable instrument and only a single simple suture is placed every load. The QuikStitch® (Pare Surgical, Englewood, CO, USA) is a mechanically assisted suture device of various sizes 3, 5, 10, and 12 mm, where the needle driver passes through a spool containing a pretied knot. Both the device and needle drivers are reusable, making it commercially more appealing than some other designs. Different needle shapes (e.g. straight or curved) and suture types (e.g. absorbable and nonabsorbable) are available [14]. Because of the technical difficulty in achieving ligation with sutures, clip systems are the preferred mechanical method for sealing blood vessels and ligation of small structures such as ducts during minimally invasive laparoscopic and robotic surgery. Clips are also faster. There are two main types of clips commonly used in our practice: metallic titanium clips and nonmetallic clips (Hem‐o‐lok). Clip appliers are classified into various categories: single‐load or multiload, and disposable or reusable “multiple uses” (Figures 82.4 and 82.5). Both types of applier can carry various types of metallic or nonmetallic clips. Figure 82.4 Multiple‐load “disposable” clip applier (10 mm Endo Clip™ II, Covidien) with its metallic titanium clips. (a) The applier has 360° rotational ability and is loaded with 10 mm clips. It has a separate trigger that reloads a clip when pulled. (b) The titanium clip has ridges and depressions along its internal surface. (c) Closure of the clip occurs from distal end first. Figure 82.5 Single‐load “reusable” metallic clip applier and the Hem‐o‐lok® (Weck®, Teleflex Medical, Morrisville, NC, USA). (a) The applier has 360° rotational ability and is loaded with a 10 mm clip. (b) The cartridge contains six clips. (c) The Hem‐o‐lok™ clip has a lock‐engagement mechanism and teeth within its jaws. The single‐load reusable clip applier has been the standard clip applier used in open and laparoscopic procedures. High‐quality reusable clip appliers are available from several manufacturers. They have the advantage of 360° rotational ability and low cost, but are not without disadvantages: The majority of clip appliers nowadays are multiloaded and disposable, carrying from 15–30 clips per unit. They are available in many models. This type of clip applier can save time and be helpful during emergency when clipping a bleeding vessel because of its ability to fire multiple clips without exiting the abdominal cavity to reload. Other characteristics include the following: The automatic reloading clip applier has a potential disadvantage in that the tips of the applier cannot be used as a dissecting instrument without dislodging the loaded clip into the field during dissection. The Hem‐o‐lok™ (Weck Closure Systems, Research Triangle Park, NC, USA) was introduced in 1999. It is a nonabsorbable radiolucent polymer clip, which has a lock‐engagement mechanism and teeth within its jaws (Figure 82.5). There are four sizes of Hem‐o‐lok clips and appliers (M, ML, L, and XL), ranging from 2 mm to 16 mm. This engaging clip latching mechanism enables the surgeon to feel the transmitted clip closure through the laparoscopic applier via tactile feedback. This design provides better security when the clip is applied to the tissue, and once engaged it is quite difficult to dislodge, even when operator tries to remove them using a purpose‐built Hem‐o‐lok clip remover. The use of Hem‐o‐lok has been reported to be safe for renal pedicle ligation during laparoscopic renal surgery [15]. Moreover, there are published reports in favor of its application during minimally invasive general surgery procedures such as appendectomy, cholecystectomy, and splenectomy [16–18]. The 5 mm Weck clip can be used during renorrhaphy of partial nephrectomy, using the sliding technique (Figure 82.6). Figure 82.6 Use of 5 mm (Weck Hem‐o‐lok Auto Endo5, Teleflex Medical) in the sliding‐clip renorrhaphy technique during robot‐assisted partial nephrectomy. (a) Application of the Weck to 3‐0 Vicryl suture and (b) cinching the thread through the Weck with the robotic needle driver. Complications are uncommon and only few cases reports have been published. Migration of the clips, although a rare problem, can cause serious complications (e.g. bowel obstruction, bladder or bowel perforation, stone formation and bladder neck contracture) that may necessitate further surgical intervention [19–23]. Hem‐o‐lok clips are contraindicated for ligation of the renal artery during laparoscopic living‐donor nephrectomy. This contraindication has been added to the instruction for use by the manufacturer Teleflex Medical in 2006, after receiving 15 medical device reports of 12 injuries and 3 deaths. Furthermore, an additional 3 kidney donor deaths have been reported since the contraindication was issued [24, 25]. Although there are published journal articles which support the continued use of Hem‐o‐lok clips for the renal artery ligation during laparoscopic living‐donor nephrectomy [26], the US Food and Drug Administration warns healthcare providers regarding this contraindication because of its potential life‐threatening complications. The basic principles of the Hem‐o‐lok and other clip types during their applications for vascular ligation are illustrated in Box 82.4. The failure rates of Hem‐o‐lok clips may be negligible when considering these principles during surgery [15, 27].
Minimally Invasive Reconstructive Techniques: Suture, Staple, and Clip Technology
Introduction
Sutures
Characteristics of suture materials
Suture length
Needle description
Needle entry
Suturing instruments
Laparoscopic needle drivers
Robotic needle drivers
Classifications of knots
The half knot
The slipknot
Blocking sequences
Classification of suturing techniques
Intracorporeal technique
Extracorporeal technique
Square knot
The Roeder slipknot
Knot‐tying devices
The Lapra‐Ty clip
The Ti‐Knot TK5
Ancillary suturing devices
The Endo Stitch
The Suture Assistant
The Sew‐Right SR5
The QuikStitch
Clips
Endoscopic clip appliers
Single‐load “reusable” clip applier
Multiple‐load “disposable” clip applier
Nonmetallic clips
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